LAMICTAL- lamotrigine_tablet

The precise mechanism(s) by which lamotrigine exerts its anticonvulsant action are unknown. In animal models designed to detect anticonvulsant activity, lamotrigine was effective in preventing seizure spread in the maximum electroshock (MES) and pentylenetetrazol (scMet) tests, and prevented seizures in the visually and electrically evoked after-discharge (EEAD) tests for antiepileptic activity. Lamotrigine also displayed inhibitory properties in the kindling model in rats both during kindling development and in the fully kindled state. The relevance of these models to human epilepsy, however, is not known. One proposed mechanism of action of lamotrigine, the relevance of which remains to be established in humans, involves an effect on sodium channels. In vitro pharmacological studies suggest that lamotrigine inhibits voltage-sensitive sodium channels, thereby stabilizing neuronal membranes and consequently modulating presynaptic transmitter release of excitatory amino acids (e. , glutamate and aspartate). Effect of Lamotrigine on N-Methyl d-Aspartate-Receptoren dashMediated Activity Lamotrigine did not inhibit N-methyl d-aspartate (NMDA)-induced depolarizations in rat cortical slices or NMDA-induced cyclic GMP formation in immature rat cerebellum, nor did lamotrigine displace compounds that are either competitive or noncompetitive ligands at this glutamate receptor complex (CNQX, CGS, TCHP). The IC 50 The mechanisms by which lamotrigine exerts its therapeutic action in bipolar disorder have not been established. Folate Metabolism In vitro, lamotrigine inhibited dihydrofolate reductase, the enzyme that catalyzes the reduction of dihydrofolate to tetrahydrofolate. Inhibition of this enzyme may interfere with the biosynthesis of nucleic acids and proteins. When oral daily doses of lamotrigine were given to pregnant rats during organogenesis, fetal, placental, and maternal folate concentrations were reduced. Significantly reduced concentrations of folate are associated with teratogenesis [see Use in Specific Populations ( 8. 1 Cardiac Electrophysiology Effect of Lamotrigine: Effect of Lamotrigine Metabolite: [see Clinical Pharmacology ( 12. 3 Accumulation in Kidneys Lamotrigine accumulated in the kidney of the male rat, causing chronic progressive nephrosis, necrosis, and mineralization. These findings are attributed to alpha-2 microglobulin, a species- and sex-specific protein that has not been detected in humans or other animal species. Melanin Binding Lamotrigine binds to melanin-containing tissues, e. , in the eye and pigmented skin. It has been found in the uveal tract up to 52 weeks after a single dose in rodents. The pharmacokinetics of lamotrigine have been studied in subjects with epilepsy, healthy young and elderly volunteers, and volunteers with chronic renal failure. Lamotrigine pharmacokinetic parameters for adult and pediatric subjects and healthy normal volunteers are summarized in Tables 14 16 Table 14. Mean Pharmacokinetic Parameters a a max b [see Drug Interactions ( 7 Adult Study Population Number of Subjects T max (h) t ½ (h) CL/F: Apparent Plasma Clearance (mL/min/kg) Healthy volunteers taking no other medications: Single-dose LAMICTAL 179 2. 10) Multiple-dose LAMICTAL 36 1. 15) Healthy volunteers taking valproate: Single-dose LAMICTAL 6 1. 42) Multiple-dose LAMICTAL 18 1. 33) Subjects with epilepsy taking valproate only: Single-dose LAMICTAL 4 4. 40) Subjects with epilepsy taking carbamazepine, phenytoin, phenobarbital, or primidone b Single-dose LAMICTAL 25 3. 04) Subjects with epilepsy taking carbamazepine, phenytoin, phenobarbital, or primidone: b Single-dose LAMICTAL 24 2. 22) Multiple-dose LAMICTAL 17 2. 82) Absorption Lamotrigine is rapidly and completely absorbed after oral administration with negligible first-pass metabolism (absolute bioavailability is 98%). The bioavailability is not affected by food. Peak plasma concentrations occur anywhere from 1. 8 hours following drug administration. The lamotrigine tablets for oral suspension were found to be equivalent, whether administered as dispersed in water, chewed and swallowed, or swallowed whole, to the lamotrigine compressed tablets in terms of rate and extent of absorption. In terms of rate and extent of absorption, lamotrigine orally disintegrating tablets, whether disintegrated in the mouth or swallowed whole with water, were equivalent to the lamotrigine compressed tablets swallowed with water. Dose Proportionality In healthy volunteers not receiving any other medications and given single doses, the plasma concentrations of lamotrigine increased in direct proportion to the dose administered over the range of 50 to 400 mg. In 2 small studies (n = 7 and 8) of patients with epilepsy who were maintained on other AEDs, there also was a linear relationship between dose and lamotrigine plasma concentrations at steady state following doses of 50 to 350 mg twice daily. Distribution Estimates of the mean apparent volume of distribution (Vd/F) of lamotrigine following oral administration ranged from 0. Vd/F is independent of dose and is similar following single and multiple doses in both patients with epilepsy and in healthy volunteers. Protein Binding Data from in vitro studies indicate that lamotrigine is approximately 55% bound to human plasma proteins at plasma lamotrigine concentrations from 1 to 10 mcg/mL (10 mcg/mL is 4 to 6 times the trough plasma concentration observed in the controlled efficacy trials). Because lamotrigine is not highly bound to plasma proteins, clinically significant interactions with other drugs through competition for protein binding sites are unlikely. The binding of lamotrigine to plasma proteins did not change in the presence of therapeutic concentrations of phenytoin, phenobarbital, or valproate. Lamotrigine did not displace other AEDs (carbamazepine, phenytoin, phenobarbital) from protein-binding sites. Metabolism Lamotrigine is metabolized predominantly by glucuronic acid conjugation; the major metabolite is an inactive 2-N-glucuronide conjugate. After oral administration of 240 mg of 14 Enzyme Induction The effects of lamotrigine on the induction of specific families of mixed-function oxidase isozymes have not been systematically evaluated. Following multiple administrations (150 mg twice daily) to normal volunteers taking no other medications, lamotrigine induced its own metabolism, resulting in a 25% decrease in t ½ [see Drug Interactions ( 7 Elimination The elimination half-life and apparent clearance of lamotrigine following oral administration of LAMICTAL to adult subjects with epilepsy and healthy volunteers is summarized in Table 14 Drug Interactions The apparent clearance of lamotrigine is affected by the coadministration of certain medications [see Warnings and Precautions ( 5. 13 7 The net effects of drug interactions with lamotrigine are summarized in Tables 13 15 Table 15. Summary of Drug Interactions with Lamotrigine a b c d e f g h i j Drug Drug Plasma Concentration with Adjunctive Lamotrigine a Lamotrigine Plasma Concentration with Adjunctive Drugs b Oral contraceptives (e. , ethinylestradiol/levonorgestrel) c left-right arrow d down arrow Aripiprazole Not assessed left-right arrow e Atazanavir/ritonavir left-right arrow f down arrow Bupropion Not assessed left-right arrow Carbamazepine left-right arrow down arrow Carbamazepine epoxide g ? Felbamate Not assessed left-right arrow Gabapentin Not assessed left-right arrow Lacosamide Not assessed left-right arrow Levetiracetam left-right arrow left-right arrow Lithium left-right arrow Not assessed Lopinavir/ritonavir left-right arrow e down arrow Olanzapine left-right arrow left-right arrow e Oxcarbazepine left-right arrow left-right arrow 10-Monohydroxy oxcarbazepine metabolite h left-right arrow Perampanel Not assessed left-right arrow e Phenobarbital/primidone left-right arrow down arrow Phenytoin left-right arrow down arrow Pregabalin left-right arrow left-right arrow Rifampin Not assessed down arrow Risperidone left-right arrow Not assessed 9-Hydroxyrisperidone i left-right arrow Topiramate left-right arrow j left-right arrow Valproate down arrow up arrow Valproate + phenytoin and/or carbamazepine Not assessed left-right arrow Zonisamide Not assessed left-right arrow Estrogen-Containing Oral Contraceptives In 16 female volunteers, an oral contraceptive preparation containing 30 mcg ethinylestradiol and 150 mcg levonorgestrel increased the apparent clearance of lamotrigine (300 mg/day) by approximately 2-fold with mean decreases in AUC of 52% and in C max Gradual transient increases in lamotrigine plasma levels (approximate 2-fold increase) occurred during the week of inactive hormone preparation (pill-free week) for women not also taking a drug that increased the clearance of lamotrigine (carbamazepine, phenytoin, phenobarbital, primidone, or other drugs such as rifampin and the protease inhibitors lopinavir/ritonavir and atazanavir/ritonavir that induce lamotrigine glucuronidation) [see Drug Interactions ( 7 In the same study, coadministration of lamotrigine (300 mg/day) in 16 female volunteers did not affect the pharmacokinetics of the ethinylestradiol component of the oral contraceptive preparation. There were mean decreases in the AUC and C max The effects of doses of lamotrigine other than 300 mg/day have not been systematically evaluated in controlled clinical trials. The clinical significance of the observed hormonal changes on ovulatory activity is unknown. However, the possibility of decreased contraceptive efficacy in some patients cannot be excluded. Therefore, patients should be instructed to promptly report changes in their menstrual pattern (e. , break-through bleeding). Dosage adjustments may be necessary for women receiving estrogen-containing oral contraceptive preparations [see Dosage and Administration ( 2. 1 Other Hormonal Contraceptives or Hormone Replacement Therapy The effect of other hormonal contraceptive preparations or hormone replacement therapy on the pharmacokinetics of lamotrigine has not been systematically evaluated. It has been reported that ethinylestradiol, not progestogens, increased the clearance of lamotrigine up to 2-fold, and the progestin-only pills had no effect on lamotrigine plasma levels. Therefore, adjustments to the dosage of LAMICTAL in the presence of progestogens alone will likely not be needed. Aripiprazole In 18 patients with bipolar disorder on a stable regimen of 100 to 400 mg/day of lamotrigine, the lamotrigine AUC and C max Atazanavir/Ritonavir In a study in healthy volunteers, daily doses of atazanavir/ritonavir (300 mg/100 mg) reduced the plasma AUC and C max Bupropion The pharmacokinetics of a 100-mg single dose of lamotrigine in healthy volunteers (n = 12) were not changed by coadministration of bupropion sustained-release formulation (150 mg twice daily) starting 11 days before lamotrigine. Carbamazepine Lamotrigine has no appreciable effect on steady-state carbamazepine plasma concentration. Limited clinical data suggest there is a higher incidence of dizziness, diplopia, ataxia, and blurred vision in patients receiving carbamazepine with lamotrigine than in patients receiving other AEDs with lamotrigine [see Adverse Reactions ( 6. 1 The addition of carbamazepine decreases lamotrigine steady-state concentrations by approximately 40%. Felbamate In a trial in 21 healthy volunteers, coadministration of felbamate (1,200 mg twice daily) with lamotrigine (100 mg twice daily for 10 days) appeared to have no clinically relevant effects on the pharmacokinetics of lamotrigine. Folate Inhibitors Lamotrigine is a weak inhibitor of dihydrofolate reductase. Prescribers should be aware of this action when prescribing other medications that inhibit folate metabolism. Gabapentin Based on a retrospective analysis of plasma levels in 34 subjects who received lamotrigine both with and without gabapentin, gabapentin does not appear to change the apparent clearance of lamotrigine. Lacosamide Plasma concentrations of lamotrigine were not affected by concomitant lacosamide (200, 400, or 600 mg/day) in placebo-controlled clinical trials in patients with partial-onset seizures. Levetiracetam Potential drug interactions between levetiracetam and lamotrigine were assessed by evaluating serum concentrations of both agents during placebo-controlled clinical trials. These data indicate that lamotrigine does not influence the pharmacokinetics of levetiracetam and that levetiracetam does not influence the pharmacokinetics of lamotrigine. Lithium The pharmacokinetics of lithium were not altered in healthy subjects (n = 20) by coadministration of lamotrigine (100 mg/day) for 6 days. Lopinavir/Ritonavir The addition of lopinavir (400 mg twice daily)/ritonavir (100 mg twice daily) decreased the AUC, C max, Olanzapine The AUC and C max max In the same trial, the AUC and C max Oxcarbazepine The AUC and C max In the same trial, the AUC and C max Perampanel In a pooled analysis of data from 3 placebo-controlled clinical trials investigating adjunctive perampanel in patients with partial-onset and primary generalized tonic-clonic seizures, the highest perampanel dose evaluated (12 mg/day) increased lamotrigine clearance by <10%. An effect of this magnitude is not considered to be clinically relevant. Phenobarbital, Primidone The addition of phenobarbital or primidone decreases lamotrigine steady-state concentrations by approximately 40%. Phenytoin Lamotrigine has no appreciable effect on steady-state phenytoin plasma concentrations in patients with epilepsy. The addition of phenytoin decreases lamotrigine steady-state concentrations by approximately 40%. Pregabalin Steady-state trough plasma concentrations of lamotrigine were not affected by concomitant pregabalin (200 mg 3 times daily) administration. There are no pharmacokinetic interactions between lamotrigine and pregabalin. Rifampin In 10 male volunteers, rifampin (600 mg/day for 5 days) significantly increased the apparent clearance of a single 25-mg dose of lamotrigine by approximately 2-fold (AUC decreased by approximately 40%). Risperidone In a 14 healthy volunteers study, multiple oral doses of lamotrigine 400 mg daily had no clinically significant effect on the single-dose pharmacokinetics of risperidone 2 mg and its active metabolite 9-OH risperidone. Following the coadministration of risperidone 2 mg with lamotrigine, 12 of the 14 volunteers reported somnolence compared with 1 out of 20 when risperidone was given alone, and none when lamotrigine was administered alone. Topiramate Topiramate resulted in no change in plasma concentrations of lamotrigine. Administration of lamotrigine resulted in a 15% increase in topiramate concentrations. Valproate When lamotrigine was administered to healthy volunteers (n = 18) receiving valproate, the trough steady-state valproate plasma concentrations decreased by an average of 25% over a 3-week period, and then stabilized. However, adding lamotrigine to the existing therapy did not cause a change in valproate plasma concentrations in either adult or pediatric patients in controlled clinical trials. The addition of valproate increased lamotrigine steady-state concentrations in normal volunteers by slightly more than 2‑fold. In 1 trial, maximal inhibition of lamotrigine clearance was reached at valproate doses between 250 and 500 mg/day and did not increase as the valproate dose was further increased. Zonisamide In a study in 18 patients with epilepsy, coadministration of zonisamide (200 to 400 mg/day) with lamotrigine (150 to 500 mg/day for 35 days) had no significant effect on the pharmacokinetics of lamotrigine. Known Inducers or Inhibitors of Glucuronidation Drugs other than those listed above have not been systematically evaluated in combination with lamotrigine. Since lamotrigine is metabolized predominately by glucuronic acid conjugation, drugs that are known to induce or inhibit glucuronidation may affect the apparent clearance of lamotrigine and doses of lamotrigine may require adjustment based on clinical response. Other In vitro assessment of the inhibitory effect of lamotrigine at OCT2 demonstrate that lamotrigine, but not the N(2)-glucuronide metabolite, is an inhibitor of OCT2 at potentially clinically relevant concentrations, with IC 50 [see Drug Interactions ( 7 Results of in vitro experiments suggest that clearance of lamotrigine is unlikely to be reduced by concomitant administration of amitriptyline, clonazepam, clozapine, fluoxetine, haloperidol, lorazepam, phenelzine, sertraline, or trazodone. Results of in vitro experiments suggest that lamotrigine does not reduce the clearance of drugs eliminated predominantly by CYP2D6. Specific Populations Patients with Renal Impairment: [see Dosage and Administration ( 2. 1 Patients with Hepatic Impairment: [see Dosage and Administration ( 2. 1 Pediatric Patients: Table 16 Population pharmacokinetic analyses involving subjects aged 2 to 18 years demonstrated that lamotrigine clearance was influenced predominantly by total body weight and concurrent AED therapy. The oral clearance of lamotrigine was higher, on a body weight basis, in pediatric patients than in adults. Weight-normalized lamotrigine clearance was higher in those subjects weighing 30 kg. Accordingly, patients weighing 30 kg being administered the same AEDs [see Dosage and Administration ( 2. Mean Pharmacokinetic Parameters in Pediatric Subjects with Epilepsy a [see Drug Interactions ( 7 b max c Pediatric Study Population Number of Subjects T max (h) t ½ (h) CL/F (mL/min/kg) Ages 10 months-5. 3 years Subjects taking carbamazepine, phenytoin, phenobarbital, or primidone a 10 3. 28) Subjects taking antiepileptic drugs with no known effect on the apparent clearance of lamotrigine 7 5. 42) Subjects taking valproate only 8 2. 77) Ages 5-11 years Subjects taking carbamazepine, phenytoin, phenobarbital, or primidone a 7 1. 58) Subjects taking carbamazepine, phenytoin, phenobarbital, or primidonea plus valproate 8 3. 93) Subjects taking valproate only b 3 4. 26) Ages 13-18 years Subjects taking carbamazepine, phenytoin, phenobarbital, or primidone a 11 ___ c ___ c 1. 3 Subjects taking carbamazepine, phenytoin, phenobarbital, or primidone a 8 ___ c ___ c 0. 5 Subjects taking valproate only 4 ___ c ___ c 0. 3 Geriatric Patients: Male and Female Patients: Racial or Ethnic Groups:.

LAMICTAL is indicated for: Epilepsyem dashadjunctive therapy in patients aged 2 years and older: 1. 1 Epilepsyem dashmonotherapy in patients aged 16 years and older: 1. 1 Bipolar disorder: 1. 2 Limitations of Use: Treatment of acute manic or mixed episodes is not recommended. Effectiveness of LAMICTAL in the acute treatment of mood episodes has not been established. Adjunctive Therapy LAMICTAL is indicated as adjunctive therapy for the following seizure types in patients aged 2 years and older: Monotherapy LAMICTAL is indicated for conversion to monotherapy in adults (aged 16 years and older) with partial-onset seizures who are receiving treatment with carbamazepine, phenytoin, phenobarbital, primidone, or valproate as the single antiepileptic drug (AED). Safety and effectiveness of LAMICTAL have not been established (1) as initial monotherapy; (2) for conversion to monotherapy from AEDs other than carbamazepine, phenytoin, phenobarbital, primidone, or valproate; or (3) for simultaneous conversion to monotherapy from 2 or more concomitant AEDs. LAMICTAL is indicated for the maintenance treatment of bipolar I disorder to delay the time to occurrence of mood episodes (depression, mania, hypomania, mixed episodes) in patients treated for acute mood episodes with standard therapy [see Clinical Studies ( 14. 2 Limitations of Use Treatment of acute manic or mixed episodes is not recommended.

1 16 2. 10 Epilepsy: Table 1 2 3 2. 2 Table 4 2. 3 Bipolar disorder: 5 6 2. 4 Rash There are suggestions, yet to be proven, that the risk of severe, potentially life-threatening rash may be increased by (1) coadministration of LAMICTAL with valproate, (2) exceeding the recommended initial dose of LAMICTAL, or (3) exceeding the recommended dose escalation for LAMICTAL. However, cases have occurred in the absence of these factors [see Boxed Warning The risk of nonserious rash may be increased when the recommended initial dose and/or the rate of dose escalation for LAMICTAL is exceeded and in patients with a history of allergy or rash to other AEDs. LAMICTAL Starter Kits and LAMICTAL ODT Patient Titration Kits provide LAMICTAL at doses consistent with the recommended titration schedule for the first 5 weeks of treatment, based upon concomitant medications, for patients with epilepsy (older than 12 years) and bipolar I disorder (adults) and are intended to help reduce the potential for rash. The use of LAMICTAL Starter Kits and LAMICTAL ODT Patient Titration Kits is recommended for appropriate patients who are starting or restarting LAMICTAL [see How Supplied/Storage and Handling ( 16 It is recommended that LAMICTAL not be restarted in patients who discontinued due to rash associated with prior treatment with lamotrigine unless the potential benefits clearly outweigh the risks. If the decision is made to restart a patient who has discontinued LAMICTAL, the need to restart with the initial dosing recommendations should be assessed. The greater the interval of time since the previous dose, the greater consideration should be given to restarting with the initial dosing recommendations. If a patient has discontinued lamotrigine for a period of more than 5 half-lives, it is recommended that initial dosing recommendations and guidelines be followed. The half-life of lamotrigine is affected by other concomitant medications [see Clinical Pharmacology ( 12. 3 LAMICTAL Added to Drugs Known to Induce or Inhibit Glucuronidation Because lamotrigine is metabolized predominantly by glucuronic acid conjugation, drugs that are known to induce or inhibit glucuronidation may affect the apparent clearance of lamotrigine. Drugs that induce glucuronidation include carbamazepine, phenytoin, phenobarbital, primidone, rifampin, estrogen-containing oral contraceptives, and the protease inhibitors lopinavir/ritonavir and atazanavir/ritonavir. Valproate inhibits glucuronidation. For dosing considerations for LAMICTAL in patients on estrogen-containing contraceptives and atazanavir/ritonavir, see below and Table 13 1 2 5 6 13 Target Plasma Levels for Patients with Epilepsy or Bipolar Disorder A therapeutic plasma concentration range has not been established for lamotrigine. Dosing of LAMICTAL should be based on therapeutic response [see Clinical Pharmacology ( 12. 3 Women Taking Estrogen-Containing Oral Contraceptives Starting LAMICTAL in Women Taking Estrogen-Containing Oral Contraceptives: [see Clinical Pharmacology ( 12. 3 1 5 7 Adjustments to the Maintenance Dose of LAMICTAL in Women Taking Estrogen-Containing Oral Contraceptives: (1) Taking Estrogen-Containing Oral Contraceptives: [see Drug Interactions ( 7 12. 3 (2) Starting Estrogen-Containing Oral Contraceptives: [see Drug Interactions ( 7 12. 3 1 5 [see Drug Interactions ( 7 12. 3 (3) Stopping Estrogen-Containing Oral Contraceptives: [see Drug Interactions ( 7 12. 3 [see Clinical Pharmacology ( 12. 3 [see Drug Interactions ( 7 12. 3 Women and Other Hormonal Contraceptive Preparations or Hormone Replacement Therapy The effect of other hormonal contraceptive preparations or hormone replacement therapy on the pharmacokinetics of lamotrigine has not been systematically evaluated. It has been reported that ethinylestradiol, not progestogens, increased the clearance of lamotrigine up to 2-fold, and the progestin-only pills had no effect on lamotrigine plasma levels. Therefore, adjustments to the dosage of LAMICTAL in the presence of progestogens alone will likely not be needed. Patients Taking Atazanavir/Ritonavir While atazanavir/ritonavir does reduce the lamotrigine plasma concentration, no adjustments to the recommended dose-escalation guidelines for LAMICTAL should be necessary solely based on the use of atazanavir/ritonavir. Dose escalation should follow the recommended guidelines for initiating adjunctive therapy with LAMICTAL based on concomitant AED or other concomitant medications (see Tables 1 2 5 [see Clinical Pharmacology ( 12. 3 Patients with Hepatic Impairment Experience in patients with hepatic impairment is limited. Based on a clinical pharmacology study in 24 subjects with mild, moderate, and severe liver impairment [see Use in Specific Populations ( 8. 3 Patients with Renal Impairment Initial doses of LAMICTAL should be based on patients’ concomitant medications (see Tables 1 3 5 [see Use in Specific Populations ( 8. 3 Discontinuation Strategy Epilepsy: If a decision is made to discontinue therapy with LAMICTAL, a step-wise reduction of dose over at least 2 weeks (approximately 50% per week) is recommended unless safety concerns require a more rapid withdrawal [see Warnings and Precautions ( 5. 10 Discontinuing carbamazepine, phenytoin, phenobarbital, primidone, or other drugs such as rifampin and the protease inhibitors lopinavir/ritonavir and atazanavir/ritonavir that induce lamotrigine glucuronidation should prolong the half-life of lamotrigine; discontinuing valproate should shorten the half-life of lamotrigine. Bipolar Disorder: [see Warnings and Precautions ( 5. 10 This section provides specific dosing recommendations for patients older than 12 years and patients aged 2 to 12 years. Within each of these age-groups, specific dosing recommendations are provided depending upon concomitant AEDs or other concomitant medications (see Table 1 Table 2 Table 3 Patients Older than 12 Years Recommended dosing guidelines are summarized in Table 1 Table 1. Escalation Regimen for LAMICTAL in Patients Older than 12 Years with Epilepsy a [see Drug Interactions ( 7 12. 3 b [see Dosage and Administration ( 2. 1 [see Dosage and Administration ( 2. 3 In Patients TAKING Valproate a In Patients NOT TAKING Carbamazepine, Phenytoin, Phenobarbital, Primidone, b a In Patients TAKING Carbamazepine, Phenytoin, Phenobarbital, or Primidone b a Weeks 1 and 2 25 mg every other 25 mg every day 50 mg/day Weeks 3 and 4 25 mg every day 50 mg/day 100 mg/day (in 2 divided doses) Week 5 onward to maintenance Increase by 25 to 50 mg/day every 1 to 2 weeks. Increase by 50 mg/day every 1 to 2 weeks. Increase by 100 mg/day every 1 to 2 weeks. Usual maintenance dose 100 to 200 mg/day with valproate alone 100 to 400 mg/day with valproate and other drugs that induce glucuronidation (in 1 or 2 divided doses) 225 to 375 mg/day (in 2 divided doses) 300 to 500 mg/day (in 2 divided doses) Patients Aged 2 to 12 Years Recommended dosing guidelines are summarized in Table 2 Lower starting doses and slower dose escalations than those used in clinical trials are recommended because of the suggestion that the risk of rash may be decreased by lower starting doses and slower dose escalations. Therefore, maintenance doses will take longer to reach in clinical practice than in clinical trials. It may take several weeks to months to achieve an individualized maintenance dose. Maintenance doses in patients weighing <30 kg, regardless of age or concomitant AED, may need to be increased as much as 50%, based on clinical response. The smallest available strength of LAMICTAL tablets for oral suspension is 2 mg, and only whole tablets should be administered. If the calculated dose cannot be achieved using whole tablets, the dose should be rounded down to the nearest whole tablet [see How Supplied/Storage and Handling ( 16 Table 2. Escalation Regimen for LAMICTAL in Patients Aged 2 to 12 Years with Epilepsy Note: Only whole tablets should be used for dosing. a [see Drug Interactions ( 7 12. 3 In Patients TAKING Valproate a In Patients NOT TAKING Carbamazepine, Phenytoin, Phenobarbital, Primidone, b a In Patients TAKING Carbamazepine, Phenytoin, Phenobarbital, or Primidone b a Weeks 1 and 2 0. 15 mg/kg/day in 1 or 2 divided doses, rounded down to the nearest whole tablet (see Table 3 0. 3 mg/kg/day in 1 or 2 divided doses, rounded down to the nearest whole tablet 0. 6 mg/kg/day in 2 divided doses, rounded down to the nearest whole tablet Weeks 3 and 4 0. 3 mg/kg/day in 1 or 2 divided doses, rounded down to the nearest whole tablet (see Table 3 0. 6 mg/kg/day in 2 divided doses, rounded down to the nearest whole tablet 1. 2 mg/kg/day in 2 divided doses, rounded down to the nearest whole tablet Week 5 onward to maintenance The dose should be increased every 1 to 2 weeks as follows: calculate 0. 3 mg/kg/day, round this amount down to the nearest whole tablet, and add this amount to the previously administered daily dose. The dose should be increased every 1 to 2 weeks as follows: calculate 0. 6 mg/kg/day, round this amount down to the nearest whole tablet, and add this amount to the previously administered daily dose. The dose should be increased every 1 to 2 weeks as follows: calculate 1. 2 mg/kg/day, round this amount down to the nearest whole tablet, and add this amount to the previously administered daily dose. Usual maintenance dose 1 to 5 mg/kg/day (maximum 200 mg/day in 1 or 2 divided doses) 1 to 3 mg/kg/day with valproate alone 4. 5 mg/kg/day (maximum 300 mg/day in 2 divided doses) 5 to 15 mg/kg/day (maximum 400 mg/day in 2 divided doses) Maintenance dose in patients <30 kg May need to be increased by as much as 50%, based on clinical response. May need to be increased by as much as 50%, based on clinical response. The Initial Weight-Based Dosing Guide for Patients Aged 2 to 12 Years Taking Valproate (Weeks 1 to 4) with Epilepsy If the patient’s weight is Give this daily dose, using the most appropriate combination of LAMICTAL 2- and 5-mg tablets Greater than And less than Weeks 1 and 2 Weeks 3 and 4 6. 7 kg 14 kg 2 mg every other 2 mg every day 14. 1 kg 27 kg 2 mg every day 4 mg every day 27. 1 kg 34 kg 4 mg every day 8 mg every day 34. 1 kg 40 kg 5 mg every day 10 mg every day Usual Adjunctive Maintenance Dose for Epilepsy The usual maintenance doses identified in Tables 1 2 without valproate valproate alone The goal of the transition regimen is to attempt to maintain seizure control while mitigating the risk of serious rash associated with the rapid titration of LAMICTAL. The recommended maintenance dose of LAMICTAL as monotherapy is 500 mg/day given in 2 divided doses. To avoid an increased risk of rash, the recommended initial dose and subsequent dose escalations for LAMICTAL should not be exceeded [see Boxed Warning Conversion from Adjunctive Therapy with Carbamazepine, Phenytoin, Phenobarbital, or Primidone to Monotherapy with LAMICTAL After achieving a dose of 500 mg/day of LAMICTAL using the guidelines in Table 1 Conversion from Adjunctive Therapy with Valproate to Monotherapy with LAMICTAL The conversion regimen involves the 4 steps outlined in Table 4 Table 4. Conversion from Adjunctive Therapy with Valproate to Monotherapy with LAMICTAL in Patients Aged 16 Years and Older with Epilepsy LAMICTAL Valproate Step 1 Achieve a dose of 200 mg/day according to guidelines in Table 1 Maintain established stable dose. Step 2 Maintain at 200 mg/day. Decrease dose by decrements no greater than 500 mg/day/week to 500 mg/day and then maintain for 1 week. Step 3 Increase to 300 mg/day and maintain for 1 week. Simultaneously decrease to 250 mg/day and maintain for 1 week. Step 4 Increase by 100 mg/day every week to achieve maintenance dose of 500 mg/day. Discontinue. Conversion from Adjunctive Therapy with Antiepileptic Drugs other than Carbamazepine, Phenytoin, Phenobarbital, Primidone, or Valproate to Monotherapy with LAMICTAL No specific dosing guidelines can be provided for conversion to monotherapy with LAMICTAL with AEDs other than carbamazepine, phenytoin, phenobarbital, primidone, or valproate. The goal of maintenance treatment with LAMICTAL is to delay the time to occurrence of mood episodes (depression, mania, hypomania, mixed episodes) in patients treated for acute mood episodes with standard therapy [see Indications and Usage ( 1. 2 Patients taking LAMICTAL for more than 16 weeks should be periodically reassessed to determine the need for maintenance treatment. Adults The target dose of LAMICTAL is 200 mg/day (100 mg/day in patients taking valproate, which decreases the apparent clearance of lamotrigine, and 400 mg/day in patients not taking valproate and taking either carbamazepine, phenytoin, phenobarbital, primidone, or other drugs such as rifampin and the protease inhibitor lopinavir/ritonavir that increase the apparent clearance of lamotrigine). In the clinical trials, doses up to 400 mg/day as monotherapy were evaluated; however, no additional benefit was seen at 400 mg/day compared with 200 mg/day [see Clinical Studies ( 14. 2 Treatment with LAMICTAL is introduced, based on concurrent medications, according to the regimen outlined in Table 5 Table 6 Table 6 If other drugs are subsequently introduced, the dose of LAMICTAL may need to be adjusted. In particular, the introduction of valproate requires reduction in the dose of LAMICTAL [see Drug Interactions ( 7 12. 3 To avoid an increased risk of rash, the recommended initial dose and subsequent dose escalations of LAMICTAL should not be exceeded [see Boxed Warning Table 5. Escalation Regimen for LAMICTAL in Adults with Bipolar Disorder a [see Drug Interactions ( 7 12. 3 In Patients TAKING Valproate a In Patients NOT TAKING Carbamazepine, Phenytoin, Phenobarbital, Primidone, b a In Patients TAKING Carbamazepine, Phenytoin, Phenobarbital, or Primidone b a Weeks 1 and 2 25 mg every other 25 mg daily 50 mg daily Weeks 3 and 4 25 mg daily 50 mg daily 100 mg daily, in divided doses Week 5 50 mg daily 100 mg daily 200 mg daily, in divided doses Week 6 100 mg daily 200 mg daily 300 mg daily, in divided doses Week 7 100 mg daily 200 mg daily up to 400 mg daily, in divided doses Table 6. Dosage Adjustments to LAMICTAL in Adults with Bipolar Disorder following Discontinuation of Psychotropic Medications a [see Drug Interactions ( 7 12. 3 Discontinuation of Psychotropic Drugs (excluding Valproate, a b After Discontinuation of Valproate a After Discontinuation of Carbamazepine, Phenytoin, Phenobarbital, or Primidone b Current Dose of LAMICTAL (mg/day) 100 Current Dose of LAMICTAL (mg/day) 400 Week 1 Maintain current dose of LAMICTAL 150 400 Week 2 Maintain current dose of LAMICTAL 200 300 Week 3 onward Maintain current dose of LAMICTAL 200 200 LAMICTAL tablets for oral suspension may be swallowed whole, chewed, or dispersed in water or diluted fruit juice. If the tablets are chewed, consume a small amount of water or diluted fruit juice to aid in swallowing. To disperse LAMICTAL tablets for oral suspension, add the tablets to a small amount of liquid (1 teaspoon, or enough to cover the medication). Approximately 1 minute later, when the tablets are completely dispersed, swirl the solution and consume the entire quantity immediately. No attempt should be made to administer partial quantities of the dispersed tablets. LAMICTAL ODT orally disintegrating tablets should be placed onto the tongue and moved around in the mouth. The tablet will disintegrate rapidly, can be swallowed with or without water, and can be taken with or without food.

The following serious adverse reactions are described in more detail in the Warnings and Precautions [see Warnings and Precautions ( 5. 1 [see Warnings and Precautions ( 5. 2 [see Warnings and Precautions ( 5. 3 [see Warnings and Precautions ( 5. 4 [see Warnings and Precautions ( 5. 5 [see Warnings and Precautions ( 5. 6 [see Warnings and Precautions ( 5. 7 [see Warnings and Precautions ( 5. 10 [see Warnings and Precautions ( 5. 11 [see Warnings and Precautions ( 5. 12 Epilepsy: 6. 1 Bipolar disorder: 6. 1 To report SUSPECTED ADVERSE REACTIONS, contact GlaxoSmithKline at 1-888-825-5249 or FDA at 1-800-FDA-1088 or www. gov/medwatch. Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in practice. Epilepsy Most Common Adverse Reactions in All Clinical Trials: Adjunctive Therapy in Adults with Epilepsy: [see Warnings and Precautions ( 5. 1 Approximately 11% of the 3,378 adult patients who received LAMICTAL as adjunctive therapy in premarketing clinical trials discontinued treatment because of an adverse reaction. The adverse reactions most commonly associated with discontinuation were rash (3. 0%), dizziness (2. 8%), and headache (2. In a dose-response trial in adults, the rate of discontinuation of LAMICTAL for dizziness, ataxia, diplopia, blurred vision, nausea, and vomiting was dose related. Monotherapy in Adults with Epilepsy: Approximately 10% of the 420 adult patients who received LAMICTAL as monotherapy in premarketing clinical trials discontinued treatment because of an adverse reaction. The adverse reactions most commonly associated with discontinuation were rash (4. 5%), headache (3. 1%), and asthenia (2. Adjunctive Therapy in Pediatric Patients with Epilepsy: In 339 patients aged 2 to 16 years with partial-onset seizures or generalized seizures of Lennox-Gastaut syndrome, 4. 2% of patients on LAMICTAL and 2. 9% of patients on placebo discontinued due to adverse reactions. The most commonly reported adverse reaction that led to discontinuation of LAMICTAL was rash. Approximately 11. 5% of the 1,081 pediatric patients aged 2 to 16 years who received LAMICTAL as adjunctive therapy in premarketing clinical trials discontinued treatment because of an adverse reaction. 4%), reaction aggravated (1. 7%), and ataxia (0. Controlled Adjunctive Clinical Trials in Adults with Epilepsy: Table 8 Table 8. Adverse Reactions in Pooled, Placebo-Controlled Adjunctive Trials in Adult Patients with Epilepsy a,b a b Body System/ Adverse Reaction Percent of Patients Receiving Adjunctive LAMICTAL (n = 711) Percent of Patients Receiving Adjunctive Placebo (n = 419) Body as a whole Headache 29 19 Flu syndrome 7 6 Fever 6 4 Abdominal pain 5 4 Neck pain 2 1 Reaction aggravated (seizure exacerbation) 2 1 Digestive Nausea 19 10 Vomiting 9 4 Diarrhea 6 4 Dyspepsia 5 2 Constipation 4 3 Anorexia 2 1 Musculoskeletal Arthralgia 2 0 Nervous Dizziness 38 13 Ataxia 22 6 Somnolence 14 7 Incoordination 6 2 Insomnia 6 2 Tremor 4 1 Depression 4 3 Anxiety 4 3 Convulsion 3 1 Irritability 3 2 Speech disorder 3 0 Concentration disturbance 2 1 Respiratory Rhinitis 14 9 Pharyngitis 10 9 Cough increased 8 6 Skin and appendages Rash 10 5 Pruritus 3 2 Special senses Diplopia 28 7 Blurred vision 16 5 Vision abnormality 3 1 Urogenital Female patients only (n = 365) (n = 207) Dysmenorrhea 7 6 Vaginitis 4 1 Amenorrhea 2 1 In a randomized, parallel trial comparing placebo with 300 and 500 mg/day of LAMICTAL, some of the more common drug-related adverse reactions were dose related (see Table 9 Table 9. Dose-Related Adverse Reactions from a Randomized, Placebo-Controlled, Adjunctive Trial in Adults with Epilepsy a P b P Adverse Reaction Percent of Patients Experiencing Adverse Reactions Placebo (n = 73) LAMICTAL 300 mg (n = 71) LAMICTAL 500 mg (n = 72) Ataxia 10 10 28 a,b Blurred vision 10 11 25 a,b Diplopia 8 24 a 49 a,b Dizziness 27 31 54 a,b Nausea 11 18 25 a Vomiting 4 11 18 a The overall adverse reaction profile for LAMICTAL was similar between females and males and was independent of age. Because the largest non-Caucasian racial subgroup was only 6% of patients exposed to LAMICTAL in placebo-controlled trials, there are insufficient data to support a statement regarding the distribution of adverse reaction reports by race. Generally, females receiving either LAMICTAL as adjunctive therapy or placebo were more likely to report adverse reactions than males. The only adverse reaction for which the reports on LAMICTAL were >10% more frequent in females than males (without a corresponding difference by gender on placebo) was dizziness (difference = 16. There was little difference between females and males in the rates of discontinuation of LAMICTAL for individual adverse reactions. Controlled Monotherapy Trial in Adults with Partial-Onset Seizures: Table 10 Table 10. Adverse Reactions in a Controlled Monotherapy Trial in Adult Patients with Partial-Onset Seizures a,b a b c d Body System/ Adverse Reaction Percent of Patients Receiving LAMICTAL c (n = 43) Percent of Patients Receiving Low-Dose Valproate d (n = 44) Body as a whole Pain 5 0 Infection 5 2 Chest pain 5 2 Digestive Vomiting 9 0 Dyspepsia 7 2 Nausea 7 2 Metabolic and nutritional Weight decrease 5 2 Nervous Coordination abnormality 7 0 Dizziness 7 0 Anxiety 5 0 Insomnia 5 2 Respiratory Rhinitis 7 2 Urogenital (female patients only) (n = 21) (n = 28) Dysmenorrhea 5 0 Adverse reactions that occurred with a frequency of 2% of patients receiving LAMICTAL and numerically more frequent than placebo were: Body as a Whole: Digestive: Metabolic and Nutritional: Nervous System: Respiratory: Skin and Appendages: Special Senses: Incidence in Controlled Adjunctive Trials in Pediatric Patients with Epilepsy: Table 11 Table 11. Adverse Reactions in Pooled, Placebo-Controlled, Adjunctive Trials in Pediatric Patients with Epilepsy a a Body System/ Adverse Reaction Percent of Patients Receiving LAMICTAL (n = 168) Percent of Patients Receiving Placebo (n = 171) Body as a whole Infection 20 17 Fever 15 14 Accidental injury 14 12 Abdominal pain 10 5 Asthenia 8 4 Flu syndrome 7 6 Pain 5 4 Facial edema 2 1 Photosensitivity 2 0 Cardiovascular Hemorrhage 2 1 Digestive Vomiting 20 16 Diarrhea 11 9 Nausea 10 2 Constipation 4 2 Dyspepsia 2 1 Hemic and lymphatic Lymphadenopathy 2 1 Metabolic and nutritional Edema 2 0 Nervous system Somnolence 17 15 Dizziness 14 4 Ataxia 11 3 Tremor 10 1 Emotional lability 4 2 Gait abnormality 4 2 Thinking abnormality 3 2 Convulsions 2 1 Nervousness 2 1 Vertigo 2 1 Respiratory Pharyngitis 14 11 Bronchitis 7 5 Increased cough 7 6 Sinusitis 2 1 Bronchospasm 2 1 Skin Rash 14 12 Eczema 2 1 Pruritus 2 1 Special senses Diplopia 5 1 Blurred vision 4 1 Visual abnormality 2 0 Urogenital Male and female patients Urinary tract infection 3 0 Bipolar Disorder in Adults The most common adverse reactions seen in association with the use of LAMICTAL as monotherapy (100 to 400 mg/day) in adult patients (aged 18 to 82 years) with bipolar disorder in the 2 double-blind, placebo-controlled trials of 18 months’ duration are included in Table 12 During the monotherapy phase of the double-blind, placebo-controlled trials of 18 months’ duration, 13% of 227 patients who received LAMICTAL (100 to 400 mg/day), 16% of 190 patients who received placebo, and 23% of 166 patients who received lithium discontinued therapy because of an adverse reaction. The adverse reactions that most commonly led to discontinuation of LAMICTAL were rash (3%) and mania/hypomania/mixed mood adverse reactions (2%). Approximately 16% of 2,401 patients who received LAMICTAL (50 to 500 mg/day) for bipolar disorder in premarketing trials discontinued therapy because of an adverse reaction, most commonly due to rash (5%) and mania/hypomania/mixed mood adverse reactions (2%). The overall adverse reaction profile for LAMICTAL was similar between females and males, between elderly and nonelderly patients, and among racial groups. Adverse Reactions in 2 Placebo-Controlled Trials in Adult Patients with Bipolar I Disorder a,b a b c [see Warnings and Precautions ( 5. 1 Body System/ Adverse Reaction Percent of Patients Receiving LAMICTAL (n = 227) Percent of Patients Receiving Placebo (n = 190) General Back pain 8 6 Fatigue 8 5 Abdominal pain 6 3 Digestive Nausea 14 11 Constipation 5 2 Vomiting 5 2 Nervous System Insomnia 10 6 Somnolence 9 7 Xerostomia (dry mouth) 6 4 Respiratory Rhinitis 7 4 Exacerbation of cough 5 3 Pharyngitis 5 4 Skin Rash (nonserious) c 7 5 Other reactions that occurred in 5% or more patients but equally or more frequently in the placebo group included: dizziness, mania, headache, infection, influenza, pain, accidental injury, diarrhea, and dyspepsia. Adverse reactions that occurred with a frequency of 1% of patients receiving LAMICTAL and numerically more frequent than placebo were: General: Cardiovascular: Digestive: Metabolic and Nutritional: Musculoskeletal: Nervous System: Respiratory: Urogenital: Adverse Reactions following Abrupt Discontinuation: [see Warnings and Precautions ( 5. 10 Mania/Hypomania/Mixed Episodes: LAMICTAL has been administered to 6,694 individuals for whom complete adverse reaction data was captured during all clinical trials, only some of which were placebo controlled. During these trials, all adverse reactions were recorded by the clinical investigators using terminology of their own choosing. To provide a meaningful estimate of the proportion of individuals having adverse reactions, similar types of adverse reactions were grouped into a smaller number of standardized categories using modified COSTART dictionary terminology. The frequencies presented represent the proportion of the 6,694 individuals exposed to LAMICTAL who experienced an event of the type cited on at least 1 occasion while receiving LAMICTAL. All reported adverse reactions are included except those already listed in the previous tables or elsewhere in the labeling, those too general to be informative, and those not reasonably associated with the use of the drug. Adverse reactions are further classified within body system categories and enumerated in order of decreasing frequency using the following definitions: frequent infrequent rare Body as a Whole Infrequent: Cardiovascular System Infrequent: Dermatological Infrequent: Rare: Digestive System Infrequent: Rare: Endocrine System Rare: Hematologic and Lymphatic System Infrequent: Rare: Metabolic and Nutritional Disorders Infrequent: Rare: Musculoskeletal System Infrequent: Rare: Nervous System Frequent: Infrequent: Rare: Respiratory System Infrequent: Rare: Special Senses Frequent: Infrequent: Rare: Urogenital System Infrequent: Rare: The following adverse reactions have been identified during postapproval use of LAMICTAL. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Blood and Lymphatic Agranulocytosis, hemolytic anemia, lymphadenopathy not associated with hypersensitivity disorder. Gastrointestinal Esophagitis. Hepatobiliary Tract and Pancreas Pancreatitis. Immunologic Hypogammaglobulinemia, lupus-like reaction, vasculitis. Lower Respiratory Apnea. Musculoskeletal Rhabdomyolysis has been observed in patients experiencing hypersensitivity reactions. Nervous System Aggression, exacerbation of Parkinsonian symptoms in patients with pre-existing Parkinson’s disease, tics. Non-site Specific Progressive immunosuppression. Renal and Urinary Disorders Tubulointerstitial nephritis (has been reported alone and in association with uveitis).

LAMICTAL is contraindicated in patients who have demonstrated hypersensitivity (e. , rash, angioedema, acute urticaria, extensive pruritus, mucosal ulceration) to the drug or its ingredients [see Boxed Warning 5. 3 Hypersensitivity to the drug or its ingredients. ( Boxed Warning 4.

7 Pregnancy Exposure Registry There is a pregnancy exposure registry that monitors pregnancy outcomes in women exposed to AEDs, including LAMICTAL, during pregnancy. Encourage women who are taking LAMICTAL during pregnancy to enroll in the North American Antiepileptic Drug (NAAED) Pregnancy Registry by calling 1-888-233-2334 or visiting http://www. aedpregnancyregistry. Risk Summary Data from several prospective pregnancy exposure registries and epidemiological studies of pregnant women have not detected an increased frequency of major congenital malformations or a consistent pattern of malformations among women exposed to lamotrigine compared with the general population (see Data) Lamotrigine decreased fetal folate concentrations in rats, an effect known to be associated with adverse pregnancy outcomes in animals and humans (see Data) The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2% to 4% and 15% to 20%, respectively. Clinical Considerations As with other AEDs, physiological changes during pregnancy may affect lamotrigine concentrations and/or therapeutic effect. There have been reports of decreased lamotrigine concentrations during pregnancy and restoration of pre-pregnancy concentrations after delivery. Dose adjustments may be necessary to maintain clinical response. Data Human Data: The NAAED Pregnancy Registry observed an increased risk of isolated oral clefts: among 2,200 infants exposed to lamotrigine early in pregnancy, the risk of oral clefts was 3. 2 per 1,000 (95% CI: 1. 3), a 3-fold increased risk versus unexposed healthy controls. This finding has not been observed in other large international pregnancy registries. Furthermore, a case-control study based on 21 congenital anomaly registries covering over 10 million births in Europe reported an adjusted odds ratio for isolated oral clefts with lamotrigine exposure of 1. 45 (95% CI: 0. Several meta-analyses have not reported an increased risk of major congenital malformations following lamotrigine exposure in pregnancy compared with healthy and disease-matched controls. No patterns of specific malformation types were observed. The same meta-analyses evaluated the risk of additional maternal and infant outcomes including fetal death, stillbirth, preterm birth, small for gestational age, and neurodevelopmental delay. Although there are no data suggesting an increased risk of these outcomes with lamotrigine monotherapy exposure, differences in outcome definition, ascertainment methods, and comparator groups limit the conclusions that can be drawn. Animal Data: 2 In a study in which pregnant rats were administered lamotrigine (oral doses of 0, 5, or 25 mg/kg) during the period of organogenesis and offspring were evaluated postnatally, neurobehavioral abnormalities were observed in exposed offspring at both doses. The lowest effect dose for developmental neurotoxicity in rats is less than the human dose of 400 mg/day on a mg/m 2 When pregnant rats were administered lamotrigine (oral doses of 0, 5, 10, or 20 mg/kg) during the latter part of gestation and throughout lactation, increased offspring mortality (including stillbirths) was seen at all doses. The lowest effect dose for pre- and post-natal developmental toxicity in rats is less than the human dose of 400 mg/day on a mg/m 2 When administered to pregnant rats, lamotrigine decreased fetal folate concentrations at doses greater than or equal to 5 mg/kg/day, which is less than the human dose of 400 mg/day on a mg/m 2 Risk Summary Lamotrigine is present in milk from lactating women taking LAMICTAL (see Data) The developmental and health benefits of breastfeeding should be considered along with the mother’s clinical need for LAMICTAL and any potential adverse effects on the breastfed infant from LAMICTAL or from the underlying maternal condition. Clinical Considerations Human milk-fed infants should be closely monitored for adverse events resulting from lamotrigine. Measurement of infant serum levels should be performed to rule out toxicity if concerns arise. Human milk-feeding should be discontinued in infants with lamotrigine toxicity. Data Data from multiple small studies indicate that lamotrigine plasma levels in nursing infants have been reported to be as high as 50% of maternal plasma concentrations. Epilepsy LAMICTAL is indicated as adjunctive therapy in patients aged 2 years and older for partial-onset seizures, the generalized seizures of Lennox-Gastaut syndrome, and PGTC seizures. Safety and efficacy of LAMICTAL used as adjunctive treatment for partial-onset seizures were not demonstrated in a small, randomized, double-blind, placebo-controlled withdrawal trial in very young pediatric patients (aged 1 to 24 months). LAMICTAL was associated with an increased risk for infectious adverse reactions (LAMICTAL 37%, placebo 5%), and respiratory adverse reactions (LAMICTAL 26%, placebo 5%). Infectious adverse reactions included bronchiolitis, bronchitis, ear infection, eye infection, otitis externa, pharyngitis, urinary tract infection, and viral infection. Respiratory adverse reactions included nasal congestion, cough, and apnea. Bipolar Disorder Safety and efficacy of LAMICTAL for the maintenance treatment of bipolar disorder were not established in a double-blind, randomized withdrawal, placebo-controlled trial that evaluated 301 pediatric patients aged 10 to 17 years with a current manic/hypomanic, depressed, or mixed mood episode as defined by DSM-IV-TR. In the randomized phase of the trial, adverse reactions that occurred in at least 5% of patients taking LAMICTAL (n = 87) and were twice as common compared with patients taking placebo (n = 86) were influenza (LAMICTAL 8%, placebo 2%), oropharyngeal pain (LAMICTAL 8%, placebo 2%), vomiting (LAMICTAL 6%, placebo 2%), contact dermatitis (LAMICTAL 5%, placebo 2%), upper abdominal pain (LAMICTAL 5%, placebo 1%), and suicidal ideation (LAMICTAL 5%, placebo 0%). Juvenile Animal Data In a juvenile animal study in which lamotrigine (oral doses of 0, 5, 15, or 30 mg/kg) was administered to young rats from postnatal day 7 to 62, decreased viability and growth were seen at the highest dose tested and long-term neurobehavioral abnormalities (decreased locomotor activity, increased reactivity, and learning deficits in animals tested as adults) were observed at the 2 highest doses. The no-effect dose for adverse developmental effects in juvenile animals is less than the human dose of 400 mg/day on a mg/m 2 Clinical trials of LAMICTAL for epilepsy and bipolar disorder did not include sufficient numbers of patients aged 65 years and older to determine whether they respond differently from younger patients or exhibit a different safety profile than that of younger patients. In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function and of concomitant disease or other drug therapy. Experience in patients with hepatic impairment is limited. Based on a clinical pharmacology study in 24 subjects with mild, moderate, and severe liver impairment [see Clinical Pharmacology ( 12. 3 [see Dosage and Administration ( 2. 1 Lamotrigine is metabolized mainly by glucuronic acid conjugation, with the majority of the metabolites being recovered in the urine. In a small study comparing a single dose of lamotrigine in subjects with varying degrees of renal impairment with healthy volunteers, the plasma half-life of lamotrigine was approximately twice as long in the subjects with chronic renal failure [see Clinical Pharmacology ( 12. 3 Initial doses of LAMICTAL should be based on patients’ AED regimens; reduced maintenance doses may be effective for patients with significant renal impairment. Few patients with severe renal impairment have been evaluated during chronic treatment with lamotrigine. Because there is inadequate experience in this population, LAMICTAL should be used with caution in these patients [see Dosage and Administration ( 2.

Significant drug interactions with LAMICTAL are summarized in this section. Uridine 5´-diphospho-glucuronyl transferases (UGT) have been identified as the enzymes responsible for metabolism of lamotrigine. Drugs that induce or inhibit glucuronidation may, therefore, affect the apparent clearance of lamotrigine. Strong or moderate inducers of the cytochrome P450 3A4 (CYP3A4) enzyme, which are also known to induce UGT, may also enhance the metabolism of lamotrigine. Those drugs that have been demonstrated to have a clinically significant impact on lamotrigine metabolism are outlined in Table 13 [see Dosage and Administration ( 2. 1 Additional details of these drug interaction studies are provided in the Clinical Pharmacology section [see Clinical Pharmacology ( 12. Established and Other Potentially Significant Drug Interactions down arrow = Decreased (induces lamotrigine glucuronidation). Concomitant Drug Effect on Concentration of Lamotrigine or Concomitant Drug Clinical Comment Estrogen-containing oral contraceptive preparations containing 30 mcg ethinylestradiol and 150 mcg levonorgestrel down arrow lamotrigine Decreased lamotrigine concentrations approximately 50%. down arrow levonorgestrel Decrease in levonorgestrel component by 19%. Carbamazepine and carbamazepine epoxide down arrow lamotrigine Addition of carbamazepine decreases lamotrigine concentration approximately 40%. ? carbamazepine epoxide May increase carbamazepine epoxide levels. Lopinavir/ritonavir down arrow lamotrigine Decreased lamotrigine concentration approximately 50%. Atazanavir/ritonavir down arrow lamotrigine Decreased lamotrigine AUC approximately 32%. Phenobarbital/primidone down arrow lamotrigine Decreased lamotrigine concentration approximately 40%. Phenytoin down arrow lamotrigine Decreased lamotrigine concentration approximately 40%. Rifampin down arrow lamotrigine Decreased lamotrigine AUC approximately 40%. Valproate up arrow lamotrigine Increased lamotrigine concentrations slightly more than 2-fold. ? valproate There are conflicting study results regarding effect of lamotrigine on valproate concentrations: 1) a mean 25% decrease in valproate concentrations in healthy volunteers, 2) no change in valproate concentrations in controlled clinical trials in patients with epilepsy. Effect of LAMICTAL on Organic Cationic Transporter 2 Substrates Lamotrigine is an inhibitor of renal tubular secretion via organic cationic transporter 2 (OCT2) proteins [see Clinical Pharmacology ( 12. 3 7 12.

OVERDOSAGE
Overdoses involving quantities up to 15 g have been reported for LAMICTAL, some of which have been fatal. Overdose has resulted in ataxia, nystagmus, seizures (including tonic-clonic seizures), decreased level of consciousness, coma, and intraventricular conduction delay. There are no specific antidotes for lamotrigine. Following a suspected overdose, hospitalization of the patient is advised. General supportive care is indicated, including frequent monitoring of vital signs and close observation of the patient. If indicated, emesis should be induced; usual precautions should be taken to protect the airway. It should be kept in mind that immediate-release lamotrigine is rapidly absorbed [see Clinical Pharmacology ( 12.
NONCLINICAL TOXICOLOGY
No evidence of carcinogenicity was seen in mice or rats following oral administration of lamotrigine for up to 2 years at doses up to 30 mg/kg/day and 10 to 15 mg/kg/day, respectively. The highest doses tested are less than the human dose of 400 mg/day on a body surface area (mg/m 2 Lamotrigine was negative in in vitro gene mutation (Ames and mouse lymphoma tk No evidence of impaired fertility was detected in rats given oral doses of lamotrigine up to 20 mg/kg/day. The highest dose tested is less than the human dose of 400 mg/day on a mg/m 2
CLINICAL STUDIES
Monotherapy with LAMICTAL in Adults with Partial-Onset Seizures Already Receiving Treatment with Carbamazepine, Phenytoin, Phenobarbital, or Primidone as the Single Antiepileptic Drug The effectiveness of monotherapy with LAMICTAL was established in a multicenter, double-blind clinical trial enrolling 156 adult outpatients with partial-onset seizures. The patients experienced at least 4 simple partial-onset, complex partial‑onset, and/or secondarily generalized seizures during each of 2 consecutive 4-week periods while receiving carbamazepine or phenytoin monotherapy during baseline. LAMICTAL (target dose of 500 mg/day) or valproate (1,000 mg/day) was added to either carbamazepine or phenytoin monotherapy over a 4-week period. Patients were then converted to monotherapy with LAMICTAL or valproate during the next 4 weeks, then continued on monotherapy for an additional 12-week period. Trial endpoints were completion of all weeks of trial treatment or meeting an escape criterion. Criteria for escape relative to baseline were: (1) doubling of average monthly seizure count, (2) doubling of highest consecutive 2-day seizure frequency, (3) emergence of a new seizure type (defined as a seizure that did not occur during the 8-week baseline) that is more severe than seizure types that occur during study treatment, or (4) clinically significant prolongation of generalized tonic-clonic seizures. The primary efficacy variable was the proportion of patients in each treatment group who met escape criteria. The percentages of patients who met escape criteria were 42% (32/76) in the group receiving LAMICTAL and 69% (55/80) in the valproate group. The difference in the percentage of patients meeting escape criteria was statistically significant ( P = Patients in the control group were intentionally treated with a relatively low dose of valproate; as such, the sole objective of this trial was to demonstrate the effectiveness and safety of monotherapy with LAMICTAL, and cannot be interpreted to imply the superiority of LAMICTAL to an adequate dose of valproate. Adjunctive Therapy with LAMICTAL in Adults with Partial-Onset Seizures The effectiveness of LAMICTAL as adjunctive therapy (added to other AEDs) was initially established in 3 pivotal, multicenter, placebo-controlled, double-blind clinical trials in 355 adults with refractory partial-onset seizures. The patients had a history of at least 4 partial-onset seizures per month in spite of receiving 1 or more AEDs at therapeutic concentrations and in 2 of the trials were observed on their established AED regimen during baselines that varied between 8 to 12 weeks. In the third trial, patients were not observed in a prospective baseline. In patients continuing to have at least 4 seizures per month during the baseline, LAMICTAL or placebo was then added to the existing therapy. In all 3 trials, change from baseline in seizure frequency was the primary measure of effectiveness. The results given below are for all partial-onset seizures in the intent-to-treat population (all patients who received at least 1 dose of treatment) in each trial, unless otherwise indicated. The median seizure frequency at baseline was 3 per week while the mean at baseline was 6. 6 per week for all patients enrolled in efficacy trials. One trial (n = 216) was a double-blind, placebo-controlled, parallel trial consisting of a 24-week treatment period. Patients could not be on more than 2 other anticonvulsants and valproate was not allowed. Patients were randomized to receive placebo, a target dose of 300 mg/day of LAMICTAL, or a target dose of 500 mg/day of LAMICTAL. The median reductions in the frequency of all partial-onset seizures relative to baseline were 8% in patients receiving placebo, 20% in patients receiving 300 mg/day of LAMICTAL, and 36% in patients receiving 500 mg/day of LAMICTAL. The seizure frequency reduction was statistically significant in the 500-mg/day group compared with the placebo group, but not in the 300-mg/day group. A second trial (n = 98) was a double-blind, placebo-controlled, randomized, crossover trial consisting of two 14-week treatment periods (the last 2 weeks of which consisted of dose tapering) separated by a 4-week washout period. The target dose of LAMICTAL was 400 mg/day. When the first 12 weeks of the treatment periods were analyzed, the median change in seizure frequency was a 25% reduction on LAMICTAL compared with placebo (P The third trial (n = 41) was a double-blind, placebo-controlled, crossover trial consisting of two 12-week treatment periods separated by a 4-week washout period. Patients could not be on more than 2 other anticonvulsants. Thirteen patients were on concomitant valproate; these patients received 150 mg/day of LAMICTAL. The 28 other patients had a target dose of 300 mg/day of LAMICTAL. The median change in seizure frequency was a 26% reduction on LAMICTAL compared with placebo ( P No differences in efficacy based on age, sex, or race, as measured by change in seizure frequency, were detected. Adjunctive Therapy with LAMICTAL in Pediatric Patients with Partial-Onset Seizures The effectiveness of LAMICTAL as adjunctive therapy in pediatric patients with partial-onset seizures was established in a multicenter, double-blind, placebo-controlled trial in 199 patients aged 2 to 16 years (n = 98 on LAMICTAL, n = 101 on placebo). Following an 8-week baseline phase, patients were randomized to 18 weeks of treatment with LAMICTAL or placebo added to their current AED regimen of up to 2 drugs. Patients were dosed based on body weight and valproate use. Target doses were designed to approximate 5 mg/kg/day for patients taking valproate (maximum dose: 250 mg/day) and 15 mg/kg/day for the patients not taking valproate (maximum dose: 750 mg/day). The primary efficacy endpoint was percentage change from baseline in all partial-onset seizures. For the intent-to-treat population, the median reduction of all partial-onset seizures was 36% in patients treated with LAMICTAL and 7% on placebo, a difference that was statistically significant ( P Adjunctive Therapy with LAMICTAL in Pediatric and Adult Patients with Lennox-Gastaut Syndrome The effectiveness of LAMICTAL as adjunctive therapy in patients with Lennox-Gastaut syndrome was established in a multicenter, double-blind, placebo-controlled trial in 169 patients aged 3 to 25 years (n = 79 on LAMICTAL, n = 90 on placebo). Following a 4-week, single-blind, placebo phase, patients were randomized to 16 weeks of treatment with LAMICTAL or placebo added to their current AED regimen of up to 3 drugs. Patients were dosed on a fixed-dose regimen based on body weight and valproate use. Target doses were designed to approximate 5 mg/kg/day for patients taking valproate (maximum dose: 200 mg/day) and 15 mg/kg/day for patients not taking valproate (maximum dose: 400 mg/day). The primary efficacy endpoint was percentage change from baseline in major motor seizures (atonic, tonic, major myoclonic, and tonic-clonic seizures). For the intent-to-treat population, the median reduction of major motor seizures was 32% in patients treated with LAMICTAL and 9% on placebo, a difference that was statistically significant ( P Adjunctive Therapy with LAMICTAL in Pediatric and Adult Patients with Primary Generalized Tonic-Clonic Seizures The effectiveness of LAMICTAL as adjunctive therapy in patients with PGTC seizures was established in a multicenter, double-blind, placebo-controlled trial in 117 pediatric and adult patients aged 2 years and older (n = 58 on LAMICTAL, n = 59 on placebo). Patients with at least 3 PGTC seizures during an 8-week baseline phase were randomized to 19 to 24 weeks of treatment with LAMICTAL or placebo added to their current AED regimen of up to 2 drugs. Patients were dosed on a fixed-dose regimen, with target doses ranging from 3 to 12 mg/kg/day for pediatric patients and from 200 to 400 mg/day for adult patients based on concomitant AEDs. The primary efficacy endpoint was percentage change from baseline in PGTC seizures. For the intent-to-treat population, the median percent reduction in PGTC seizures was 66% in patients treated with LAMICTAL and 34% on placebo, a difference that was statistically significant ( P Adults The effectiveness of LAMICTAL in the maintenance treatment of bipolar I disorder was established in 2 multicenter, double-blind, placebo-controlled trials in adult patients (aged 18 to 82 years) who met DSM-IV criteria for bipolar I disorder. Trial 1 enrolled patients with a current or recent (within 60 days) depressive episode as defined by DSM-IV and Trial 2 included patients with a current or recent (within 60 days) episode of mania or hypomania as defined by DSM-IV. Both trials included a cohort of patients (30% of 404 subjects in Trial 1 and 28% of 171 patients in Trial 2) with rapid cycling bipolar disorder (4 to 6 episodes per year). In both trials, patients were titrated to a target dose of 200 mg of LAMICTAL as add-on therapy or as monotherapy with gradual withdrawal of any psychotropic medications during an 8- to 16-week open-label period. Overall 81% of 1,305 patients participating in the open-label period were receiving 1 or more other psychotropic medications, including benzodiazepines, selective serotonin reuptake inhibitors (SSRIs), atypical antipsychotics (including olanzapine), valproate, or lithium, during titration of LAMICTAL. Patients with a CGI-severity score of 3 or less maintained for at least 4 continuous weeks, including at least the final week on monotherapy with LAMICTAL, were randomized to a placebo-controlled double-blind treatment period for up to 18 months. The primary endpoint was TIME (time to intervention for a mood episode or one that was emerging, time to discontinuation for either an adverse event that was judged to be related to bipolar disorder, or for lack of efficacy). The mood episode could be depression, mania, hypomania, or a mixed episode. In Trial 1, patients received double-blind monotherapy with LAMICTAL 50 mg/day (n = 50), LAMICTAL 200 mg/day (n = 124), LAMICTAL 400 mg/day (n = 47), or placebo (n = 121). LAMICTAL (200- and 400-mg/day treatment groups combined) was superior to placebo in delaying the time to occurrence of a mood episode (Figure 1). Separate analyses of the 200- and 400-mg/day dose groups revealed no added benefit from the higher dose. In Trial 2, patients received double-blind monotherapy with LAMICTAL (100 to 400 mg/day, n = 59), or placebo (n = 70). LAMICTAL was superior to placebo in delaying time to occurrence of a mood episode (Figure 2). The mean dose of LAMICTAL was about 211 mg/day. Although these trials were not designed to separately evaluate time to the occurrence of depression or mania, a combined analysis for the 2 trials revealed a statistically significant benefit for LAMICTAL over placebo in delaying the time to occurrence of both depression and mania, although the finding was more robust for depression. Figure 1: Kaplan-Meier Estimation of Cumulative Proportion of Patients with Mood Episode (Trial 1) Figure 2: Kaplan-Meier Estimation of Cumulative Proportion of Patients with Mood Episode (Trial 2) Figure 1: Kaplan-Meier Estimation of Cumulative Proportion of Patients with Mood Episode (Trial 1) Figure 2: Kaplan-Meier Estimation of Cumulative Proportion of Patients with Mood Episode (Trial 2).

LAMICTAL- lamotrigine_tablet, for suspension

LAMICTAL- lamotrigine_tablet Product manual source documgent