Quetiapine Fumarate Tablets

Pharmacodynamic properties Quetiapine is an atypical antipsychotic that interacts with multiple neurotransmitter receptors. In the brain, quetiapine has a high affinity for serotonin (5HT2) receptors, which is greater than the affinity for dopamine D1 and dopamine D2 receptors in the brain. Quetiapine also has a high affinity for histamine receptors and adrenergic α1 receptors, a low affinity for adrenergic α1 receptors, but has little affinity for cholinergic receptors or benzodiazepine receptors. Quetiapine showed positive results in antipsychotic activity assays such as conditioned avoidance reflexes. Quetiapine tablets do not produce a persistent increase in prolactin. In a multiple-dose clinical trial, it was found that there was no difference in the changes in prolactin levels in different doses of quetiapine groups, and there was no difference between the placebo group. Clinical trials have shown that quetiapine tablets are effective in treating both positive and negative symptoms of schizophrenia. One trial compared with chlorpromazine and two trials compared with haloperidol showed that the short-term efficacy of quetiapine tablets was comparable to that of the control drug. Toxicology Acute toxicity studies The acute toxicity of quetiapine is very low. Oral (500 mg/kg) or intraperitoneal injection (100 mg/kg) administration to mice and rats resulted in typical antipsychotic effects. Repeated dose toxicity studies in rats, dogs and monkeys showed the expected antipsychotic-like central nervous system effects (such as sedation at low doses, tremor, convulsion or weakness at high doses). Reversible morphological and functional effects on the liver consistent with induction of liver enzymes were observed in mice, rats and monkeys. Thyroid cell hyperplasia and corresponding changes in plasma thyroid hormone levels were observed in rats and monkeys. Transient increases in heart rate have occurred in dogs, but were not accompanied by effects on blood pressure. Cataracts were not found in monkeys or rodents at doses up to 225 mg/kg/day. No drug-related corneal opacities were found in human clinical studies monitoring. No neutropenia or agranulocytosis was found in all toxicity studies. Reproductive toxicity studies showed that quetiapine had no teratogenic effects. Mutagenicity studies Genetic toxicology studies on quetiapine showed that quetiapine had no mutagenic or clastogenic effects.

25 mg tablets: round, 6 mm, pink, biconvex, coated tablets. 100 mg tablets: round, 8.5 mm, yellow, biconvex, coated tablets. 200 mg tablets: round, 11 mm, white, biconvex, coated tablets.

Quetiapine fumarate tablets are used to treat schizophrenia; quetiapine fumarate tablets are used to treat manic episodes of bipolar disorder.

Oral, twice a day, before or after meals. Adults: For the treatment of schizophrenia: The total daily dose at the beginning of treatment is: 50 mg on the first day, 100 mg on the second day, 200 mg on the third day, and 300 mg on the fourth day. From the fourth day onwards, the dose is gradually increased to the effective dose range, generally 300-450 mg per day. The dose can be adjusted to 150-750 mg per day based on the patient's clinical response and tolerance. For the treatment of manic episodes of bipolar disorder: When used as a monotherapy or adjunctive therapy with mood stabilizers, the total daily dose at the beginning of treatment is 100 mg on the first day, 200 mg on the second day, 300 mg on the third day, and 400 mg on the fourth day. The dose can be further adjusted to 800 mg per day on the sixth day, but the daily dose increase should not exceed 200 mg. The dose can be adjusted to 200-800 mg per day based on the patient's clinical response and tolerance, and the commonly used effective dose range is 400-800 mg per day. Elderly patients: Like other antipsychotic drugs, this product should be used with caution in elderly patients, especially when starting to take the drug. The starting dose for elderly patients should be 25 mg per day. Then increase the dose by 25-50 mg per day to the effective dose, but the effective dose may be lower than that of younger patients. Patients with renal and hepatic impairment: The clearance of quetiapine after oral administration is reduced by about 25% in patients with renal and hepatic impairment. Quetiapine is extensively metabolized in the liver, so it should be used with caution in patients with hepatic impairment. For patients with renal or hepatic impairment, the starting dose of this product should be 25 mg per day. Then increase the dose by 25-50 mg per day to the effective dose. Or follow the doctor's advice.

The most common and significant adverse events reported in short-term controlled trials of quetiapine were drowsiness (17.5%), dizziness (10%), constipation (9%), postural hypotension (7%), dry mouth (7%), and abnormal liver enzymes (6%). As with other antipsychotics with alpha-1 adrenergic blocking properties, quetiapine may cause orthostatic hypotension (with dizziness), palpitations, and syncope in some patients; these events tend to occur during the initial dose increase period. Seizures have been reported occasionally in patients taking quetiapine, but the incidence is no greater than that in the placebo group. As with other antipsychotics, neuroleptic malignant syndrome is rare in patients treated with quetiapine. As with other antipsychotics, quetiapine is associated with changes in white blood cell counts, with an incidence of 1.6% reported in controlled clinical trials. Eosinophilia has been reported occasionally. Asymptomatic increases in serum aminotransferases (ALT, AST) or ψ-GT levels have been observed in some patients taking quetiapine. This increase usually recovers during continued quetiapine treatment. Mild increases in serum triglycerides and total cholesterol levels in the nonfasting state have been observed during quetiapine treatment. Quetiapine treatment may be associated with mild, dose-related decreases in thyroid hormone levels, particularly total T4 and free T4. The effects on total T4 and free T4 recover in almost all patients after quetiapine is discontinued.

Quetiapine tablets are contraindicated in patients who are allergic to any of the components of the product.

Precautions during pregnancy and lactation: The efficacy and safety of quetiapine tablets in human pregnancy have not been confirmed. The excretion of quetiapine in human breast milk is not yet clear. If a lactating woman takes quetiapine, she should be advised to discontinue breastfeeding during the medication period.

The co-administration of quetiapine tablets with lithium will not affect the pharmacokinetics of lithium, and will not induce the liver enzyme system related to the metabolism of antipyrine. The co-administration of quetiapine tablets with phenytoin can increase the clearance of quetiapine. If quetiapine is co-administered with phenytoin or other liver enzyme inducers (such as carbamazepine, barbiturates, rifampicin), the dose of quetiapine tablets should be increased to maintain the effect of antipsychotic symptoms. If phenytoin is discontinued and replaced with a non-inducing agent (such as sodium valproate), the dose of quetiapine tablets needs to be reduced. The co-administration of antipsychotic drugs risperidone or haloperidol will not significantly change the pharmacokinetics of quetiapine. However, the co-administration of quetiapine tablets with thioridazine will increase the clearance of quetiapine. The co-administration of quetiapine tablets with the antidepressants imipramine or fluoxetine will not significantly change the pharmacokinetics of quetiapine. Among the cytochrome P450 enzymes, the main enzyme mediating metabolism is CYP3A4. Co-administration with cimetidine or fluoxetine (both known P450 inhibitors) did not alter the pharmacokinetics of quetiapine, but caution should be exercised if quetiapine tablets are co-administered with strong inhibitors of CYP3A4 (such as systemic ketoconazole or erythromycin).

Store below 30°C.

25mg*20 tablets

3 years.

AstraZeneca Pharmaceutical Co., Ltd.

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