Fexofenadine

501.66

501.66

1533716-785-6

C61764

Crystals from methanol-butanone

R - Respiratory system

2933399090

81

3

1.2±0.1 g/cm3

142.5 °C

697.3°C at 760 mmHg

375.5±31.5 °C

1.597

In water, 2.4X10-2 mg/L at 25 deg C (est)

-20°C Freezer

pKa1 = 8.76 (tertiary nitrogen); pKa2 4.28 (carboxylic acid) (est)

226.9 Ų [M+H]+ [CCS Type: TW, Method: Major Mix IMS/Tof Calibration Kit (Waters)]

Molecular weight is 538.13. Fexofenadine hydrochloride is a white to off-white crystalline powder. It is freely soluble in methanol and ethanol, slightly soluble in chloroform and water, and insoluble in hexane. Fexofenadine hydrochloride is a racemate and exists as a zwitterion in aqueous media at physiological pH /Hydrochloride/

Commercially available fexofenadine hydrochloride capsules have an expiration date of 18 or 24 months after the date of manufacture when packaged in the manufacturer's unopened blister packages or high-density polyethylene bottles, respectively. Commercially available fexofenadine hydrochloride 30-mg conventional tablets have an expiration date of 18 months after the date of manufacture when packaged either in the manufacturer's unopened blister packages or high-density polyethylene bottles, whe

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

The Approved Drug Products with Therapeutic Equivalence Evaluations List identifies currently marketed prescription drug products, incl fexofenadine hydrochloride, approved on the basis of safety and effectiveness by FDA under sections 505 of the Federal Food, Drug, and Cosmetic Act. /fexofenadine hydrochloride/

No deaths were observed following the oral administration of up to 5000 mg/kg in both mice and rats (equivalent to approximately 100-200x the recommended human dose). Single doses of up to 800 mg and chronic exposure of up to 690 mg twice daily for 1 month in humans did not result in clinically significant adverse events. Symptoms of overdosage are consistent with fexofenadine's adverse effect profile and are likely to include dizziness, drowsiness, and dry mouth. If overdosage occurs, employ symptomatic and supportive treatment. Hemodialysis does not effectively remove fexofenadine from the blood and is therefore of no benefit.

Fexofenadine use is not generally associated with liver enzyme elevations but terfenadine, a second generation antihistamine that is metabolized in part to fexofenadine, was the attributed cause of several reported cases of clinically apparent liver injury. Terfenadine was also linked to cardiac arrhythmias and prolongation of the QTc interval for which reason it was withdrawn from use in 1997, just as fexofenadine was introduced. Liver injury from terfenadine typically arose after 1 to 5 months and was associated with a hepatocellular pattern of liver enzyme abnormalities without immunoallergic or autoimmune features. Fexofenadine has not been linked to similar cases of cardiac arrhythmias or liver injury.

Increased concentrations of fexofenadine have been reported in 2 controlled drug interaction studies in healthy individuals receiving 120 mg of fexofenadine hydrochloride twice daily concomitantly with erythromycin dosages of 500 mg every 8 hours or ketoconazole 400 mg once daily. In these studies, area under the plasma-concentration time curve (AUC) of fexofenadine increased by 109 or 164% following concomitant administration with erythromycin or ketoconazole, respectively, while peak plasma concentrations of fexofenadine increased by 82 or 135%, respectively. However, no clinically important adverse effects or changes in the QT interval corrected for rate (QTc) were reported after concomitant administration of erythromycin or ketoconazole with fexofenadine.|Administration of a single 120-mg dose (2 capsules of 60 mg) of fexofenadine hydrochloride within 15 minutes of administration of an aluminum and magnesium hydroxides antacid (Maalox) decreased the AUC and peak plasma concentration of fexofenadine by 41 and 43%, respectively. Therefore, the manufacturer states that fexofenadine (alone or in fixed combination with pseudoephedrine hydrochloride) should not be taken closely in time with antacids containing aluminum and magnesium.|Fruit (grapefruit, orange, apple) juices may reduce bioavailability and systemic exposure of fexofenadine. In clinical studies, the size of wheal and flare was substantially larger when fexofenadine hydrochloride was administered with grapefruit juice or orange juice compared with water; based on literature reports, the same effects may be extrapolated to other fruit juices such as apple juice. The clinical importance of these observations is unknown. Based on a population pharmacokinetic analysis of combined data from the studies using concomitant grapefruit juice or orange juice with data from a bioequivalence study, bioavailability of fexofenadine was reduced by 36%. Therefore, to maximize the effects of fexofenadine, the manufacturer recommends that the drug be administered with water.

Safety and efficacy of fexofenadine hydrochloride have not been established in children younger than 6 years of age.

Fexofenadine is 60-70% bound to plasma proteins, primarily to albumin and α₁-acid glycoprotein. The extent of protein binding is decreased to 56-68% and 56-75% in patients with renal and hepatic impairment, respectively.

While data specific to fexofenadine were not located(SRC, 2006), the literature suggests that some pharmaceutically active compounds originating from human and veterinary therapy are not eliminated completely in municipal sewage treatment plants and are therefore discharged into receiving waters(1). Wastewater treatment processes often were not designed to remove them from the effluent(2). Selected organic waste compounds may be degrading to new and more persistent compounds that may be released instead of or in addition to the parent compound(2).

It is not known if fexofenadine hydrochloride is distributed into breast milk

In the United States, fexofenadine is indicated for the symptomatic treatment of allergic rhinitis in patients ≥2 years old and chronic idiopathic urticaria in patients ≥6 months old. In Canada, fexofenadine carries the same indications but is approved only for patients ≥12 years old. Fexofenadine is also available in combination with [pseudoephedrine] for the symptomatic treatment of season allergic rhinitis in patients ≥12 years old.|FDA Label

Fexofenadine is a second generation antihistamine that is used for the treatment of allergic rhinitis, angioedema and chronic urticaria. Fexofenadine has not been linked to serum enzyme elevations during therapy or to instances of clinically apparent acute liver injury.

Antihistamines

Histamine H1 antagonists|Antihistaminic|Fexofenadine is indicated to relieve symptoms that are associated with seasonal allergic rhinitis, such as sneezing;rhinorrhea; itchy eyes, nose and throt; and red watery eyes. /Included in US product label/|Fexofenadine is indicated for the treatment of uncomplicated skin manifestations of chronic idiopathic urticaria. It significantly reduces pruritus and the number of wheals. /Included in US product label/

In controlled clinical studies in patients 12 years of age and older with allergic rhinitis receiving oral fexofenadine hydrochloride dosages of 60 mg twice daily or placebo, drowsiness or fatigue occurred in 1.3% of patients, compared with 0.9% of those receiving placebo. In these studies in patients receiving fexofenadine hydrochloride dosages of 180 mg once daily (as conventional tablets) or placebo, headache was reported in 10.6 or 7.5% of patients, respectively. In controlled studies in children 6-11 years of age with seasonal allergic rhinitis receiving fexofenadine hydrochloride dosages of 30 mg twice daily or placebo, headache was reported in 7.2 or 6.6% of patients, respectively, while pain was reported in 2.4 or 0.4% of patients, respectively.|Sleep disorder, insomnia, or paroniria has occurred in patients receiving fexofenadine hydrochloride.|During controlled clinical studies, nausea and dyspepsia were reported in 1.6 and 1.3%, respectively, of patients receiving oral fexofenadine hydrochloride dosages of 60 mg twice daily versus 1.5 and 0.6%, respectively, of those receiving placebo.|Clinical data from over 2000 patients indicate that fexofenadine hydrochloride lacks the cardiotoxic potential of its parent drug terfenadine. In 714 patients with seasonal allergic rhinitis, fexofenadine hydrochloride dosages of 60-240 mg twice daily were not associated with statistically significant mean increases in the QT interval corrected for rate (QTc) in controlled clinical studies. In addition, in 231 healthy individuals, fexofenadine hydrochloride dosages of 240 mg given once daily for 1 year also were not associated with statistically significant increases in the mean QTc. Even at dosages exceeding these (e.g., up to 400 mg twice daily for 6 days in 40 patients, up to 690 mg twice daily for about 1 month in 32 patients, up to 800 mg given in a single dose in 87 patients), statistically significant mean increases in the QTc or other ECG abnormalities have not been reported in healthy adults or patients with seasonal allergic rhinitis.|For more Drug Warnings (Complete) data for FEXOFENADINE (15 total), please visit the HSDB record page.

There was no evidence of tolerance to these effects (tachyphylaxis) after 28 days of therapy /with fexofenadine/...

Fexofenadine relieves allergy symptoms by antagonizing the actions of histamine, an endogenous compound predominantly responsible for allergic symptomatology. The relatively long duration of action of fexofenadine (approximately 24 hours) allows for once or twice daily dosing, and its rapid absorption allows for an onset of action within 1-3 hours. Fexofenadine should not be taken with fruit juice, as this may impair its absorption.

A class of non-sedating drugs that bind to but do not activate histamine receptors (DRUG INVERSE AGONISM), thereby blocking the actions of histamine or histamine agonists. These antihistamines represent a heterogenous group of compounds with differing chemical structures, adverse effects, distribution, and metabolism. Compared to the early (first generation) antihistamines, these non-sedating antihistamines have greater receptor specificity, lower penetration of BLOOD-BRAIN BARRIER, and are less likely to cause drowsiness or psychomotor impairment. (See all compounds classified as Histamine H1 Antagonists, Non-Sedating.)|Agents that are used to treat allergic reactions. Most of these drugs act by preventing the release of inflammatory mediators or inhibiting the actions of released mediators on their target cells. (From AMA Drug Evaluations Annual, 1994, p475) (See all compounds classified as Anti-Allergic Agents.)

Fexofenadine is rapidly absorbed following oral administration and its absolute bioavailability is approximately 33%. The T_max following oral administration is approximately 1-3 hours. The steady-state AUC_ss(0-12h) and C_max following twice daily dosing of 60mg are 1367 ng/mL.h and 299 ng/mL, respectively. Fexofenadine AUC is decreased by >20% when coadministered with fruit juices (e.g. apple, orange, grapefruit) due to their inhibition of OATP transporters - for this reason, prescribing information recommends administering fexofenadine only with water. Similarly, coadministration of fexofenadine with a high-fat meal appears to decrease AUC and C_max by >20%.|Approximately 80% of an ingested dose is eliminated in the feces, likely largely unchanged due to fexofenadine's limited metabolism, and 11% is eliminated in the urine. The principal pathways of fexofenadine elimination are biliary and renal.|The volume of distribution is approximately 5.4-5.8 L/kg.|The oral clearance of fexofenadine is approximately 50.6 L/h and the renal clearance is approximately 4.32 L/h.|Fexofenadine hydrochloride is rapidly absorbed from the GI tract following oral administration. Following oral administration of two 60-mg fexofenadine hydrochloride capsules, peak plasma concentrations are achieved in about 2.6 hours. Following oral administration of a single 60-mg capsule or 60- or 180-mg conventional tablet in healthy individuals, mean peak plasma concentrations were 131, 142, and 494 ng/mL, respectively. In healthy men, peak plasma concentrations of 167 ng/mL were achieved within 1.42 hours following oral administration of 60-mg fexofenadine hydrochloride doses every 12 hours for 9 doses.|Following oral administration of fexofenadine hydrochloride capsules in fasting children (mean age: 8-11.6 years) with a history of allergic rhinitis with or without mild asthma, peak plasma fexofenadine concentrations of about 178 or 286 ng/mL were attained in approximately 2.4 hours after a 30- or 60-mg dose, respectively.|Following oral administration of a 60-mg dose of fexofenadine hydrochloride, the AUC was 56% greater in children 7-12 years of age with allergic rhinitis than in healthy adults. Plasma exposure in children receiving 30 mg of fexofenadine hydrochloride is similar to that of adults receiving 60 mg of the drug. Limited data indicate that peak plasma fexofenadine concentrations in adolescents (12-16 years of age) were similar to those in adults, while peak plasma concentrations in geriatric adults (65 years of age and older) were 99% greater than in healthy individuals younger than 65 years of age. AUC also was higher in geriatric adults (65-80 years of age) than in younger adults (19-45 years of age)...|Peak plasma concentrations of fexofenadine were 87 and 111% higher in patients with mild (creatinine clearance of 41-80 mL/minute) to severe (creatinine clearance of 11-40 mL/minute) renal impairment, respectively, compared with those observed in healthy adults. In patients undergoing dialysis (creatinine clearance of 10 mL/minute or less), peak plasma concentrations of fexofenadine were 82% higher than in healthy adults.|For more Absorption, Distribution and Excretion (Complete) data for FEXOFENADINE (12 total), please visit the HSDB record page.

Fexofenadine is very minimally metabolized, with only 5% of an ingested dose undergoing hepatic metabolism. The only identified metabolites are a methyl ester of fexofenadine (3.6% of the total dose) and MDL 4829 (1.5% of the total dose). The enzymes responsible for this metabolism have not been elucidated.|About 5% of a single oral dose of fexofenadine is metabolized.|Negligible amounts of fexofenadine (about 0.5-1.5% of a dose) are metabolized in the liver by the cytochrome P-450 microsomal enzyme system to an inactive metabolite, while about 3.5% of a fexofenadine dose is metabolized by a second metabolic pathway (unrelated to the cytochrome P-450 microsomal enzyme system) to the methyl ester derivative of fexofenadine. The methyl ester metabolite of fexofenadine is found only in feces, and it has been suggested that the intestinal flora probably are involved in this metabolism.

The terminal elimination half-life is approximately 11-15 hours.|Following oral administration of 60 mg of fexofenadine hydrochloride twice daily in healthy individuals, the mean elimination half-life of the drug at steady state reportedly is about 14.4-14.6 hours; mean elimination half-life reportedly was similar in geriatric adults (65 years of age or older) who received a single 80-mg oral dose of fexofenadine hydrochloride.|... Elimination half-life was about 18 hours in fasting children (mean age: 8-11.6 years) who received single oral 30- or 60-mg doses of fexofenadine hydrochloride as capsules.|In patients with mild (creatinine clearance of 41-80 mL/minute) to severe (creatinine clearance of 11-40 mL/minute) renal impairment, mean elimination half-lives were 59 and 72% longer than those observed in healthy individuals, respectively.|In patients undergoing dialysis (creatinine clearance of 10 mL/minute or less), elimination half-life was 31% longer than in healthy individuals.

The H₁ histamine receptor is responsible for mediating hypersensitivity and allergic reactions. Exposure to an allergen results in degranulation of mast cells and basophils, which then release histamine and other inflammatory mediators. Histamine binds to, and activates, H₁ receptors, which results in the further release of pro-inflammatory cytokines, such as interleukins, from basophils and mast cells. These downstream effects of histamine binding are responsible for a wide variety of allergic symptoms, such as pruritus, rhinorrhea, and watery eyes. Fexofenadine is considered an “inverse agonist” of the H₁ receptor because it binds to and stabilizes the inactive form of the receptor, preventing its activation and subsequent downstream effects. It has a potent and selective affinity for H₁ receptors, and there is no evidence that it carries antidopaminergic, antiserotonergic, anticholinergic, sedative, or adrenergic blocking activity. Fexofenadine does not cross the blood-brain barrier and thus is unlikely to cause significant CNS effects.|Fexofenadine is a specific, selective, histamine H1-receptor antagonist. ... Fexofenadine has been shown to inhibit histamine release from peritoneal mast cells in rats. Unlike terfenadine, fexofenadine does not block the potassium channel involved in repolarization of cardiac cells (i.e., blockade of the delayed rectifier potassium current IK). As a result, fexofenadine lacks the cardiotoxic potential of terfenadine. Fexofenadine also does not possess appreciable anticholinergic, antidopaminergic, or alpha- or beta-adrenergic blocking effects at usual antihistaminic doses in pharmacologic studies.|It has been suggested that the increased safety profile of fexofenadine compared with the parent drug results from the lack of fexofenadine-induced cardiotoxicity in addition to only minimal metabolism of fexofenadine in the liver by the cytochrome P-450 microsomal enzyme system. Evidence from animal models using fexofenadine have suggested that the apparent lack of cardiotoxic effects of the drug may have resulted at least in part from lack of blockade of the potassium channel involved in repolarization of cardiac cells (ie, blockade of the delayed rectifier potassium current IK). Prolongations in the QTc interval were not reported in dogs receiving oral fexofenadine hydrochloride dosages of 10 mg/kg daily for 5 days or in rabbits receiving an IV fexofenadine hydrochloride dose of 10 mg/kg (resulting in plasma fexofenadine concentrations 28 or 63 times the therapeutic plasma concentrations in humans, respectively, based on a dosage of 60 mg of fexofenadine hydrochloride given twice daily). In addition, no effect was observed on calcium-channel current, delayed potassium-channel current, or action potential duration in guinea pig myocytes, sodium current in rat neonatal myocytes, or on the delayed rectifier potassium channel cloned from human heart at fexofenadine concentrations up to 1.0 X10-5 M (approximately equivalent to 32 times the therapeutic plasma concentrations in humans, based on a dosage of 60 mg of fexofenadine hydrochloride given twice daily).|In vitro, terfenadine exhibits a similar affinity for histamine H1-receptors from brain and peripheral tissues; however, in vivo, unlike first generation antihistamines, terfenadine and fexofenadine do not readily cross the blood-brain barrier and therefore do not appear to interact appreciably with H1-receptors within the CNS at usual doses.

For the treatment of fexofenadine overdosage, usual measures to remove unabsorbed drug from the GI tract, and supportive and symptomatic treatment should be initiated. Experience with terfenadine (no longer commercially available in the US), the parent drug, indicates that fexofenadine is not effectively removed by hemodialysis.|Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 ml/kg up to 200 ml of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . Cover skin burns with dry sterile dressings after decontamination ... . /Poisons A and B/|Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam or lorazepam ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Poisons A and B/

Allegra

Oral, Capsules, 60 mg, Allegra, Sanofi-Aventis; Tablets, film-coated, 30 mg, Allegra ( with povidone), Sanofi-Aventis 60 mg, Allegra ( with povidone), Sanofi-Aventis 180 mg, Allegra ( with povidone), Sanofi-Aventis

Analyte: fexofenadine hydrochloride; matrix: chemical identification; procedure: infrared absorption spectrophotometry with comparison to standards /fexofenadine hydrochloride/|Analyte: fexofenadine hydrochloride; matrix: chemical identification; procedure: retention time of the major peak of the liquid chromatogram with comparison to standards /fexofenadine hydrochloride/|Analyte: fexofenadine hydrochloride; matrix: chemical identification; procedure: differential scanning calorimetry with analysis between 25 °C and 225 °C; sample exhibits single endotherm between 193 °C and 199 °C /fexofenadine hydrochloride/|Analyte: fexofenadine hydrochloride; matrix: chemical purity; procedure: liquid chromatography with detection at 220 nm and comparison to standards /fexofenadine hydrochloride/|For more Analytic Laboratory Methods (Complete) data for FEXOFENADINE (7 total), please visit the HSDB record page.

Human Drugs -> FDA Approved Drug Products with Therapeutic Equivalence Evaluations (Orange Book) -> Active Ingredients|Pharmaceuticals