Quetiapine hemifumarate

Quetiapine hemifumarate is indicated for the treatment of schizophrenia as well as for the treatment of acute manic episodes associated with bipolar I disorder. The antipsychotic effect of quetiapine is thought by some to be mediated through antagonist activity at dopamine and serotonin receptors. Specifically the D1 and D2 dopamine, the alpha 1 adrenoreceptor and alpha 2 adrenoreceptor, and 5-HT1A and 5-HT2 serotonin receptor subtypes are antagonized. Quetiapine hemifumarate also has an antagonistic effect on the histamine H1 receptor.

Medicinal name:
  • Quetiapine 200 MG Oral Tablet
  • Quetiapine 300 MG Oral Tablet
  • Quetiapine 400 MG Oral Tablet
  • Quetiapine 25 MG Oral Tablet
  • Quetiapine 100 MG Oral Tablet
  • Quetiapine 50 MG Oral Tablet
  • Quetiapine 150 MG Oral Tablet
  • Quetiapine (as quetiapine fumarate) 25 MG Oral Tablet

Quetiapine hemifumarate - Pharmacology:

The mechanism of action of quetiapine, as with other drugs used to treat schizophrenia, is unknown. However, it is thought that the drug's therapeutic activity in schizophrenia is mediated through a combination of dopamine type 2 (D2) and serotonin type 2 (5HT2) receptor antagonism. Although quetiapine is known to bind other receptors with similar affinity, only the dopamine D2 and serotonin 5HT2 receptor binding is responsible for quetiapine's therapeutic activity in schizophrenia.

Quetiapine hemifumarate for patients

Physicians are advised to discuss the following issues with patients for whom they prescribe SEROQUEL. Orthostatic Hypotension: Patients should be advised of the risk of orthostatic hypotension, especially during the 3-5 day period of initial dose titration, and also at times of re-initiating treatment or increases in dose.
Interference with Cognitive and Motor Performance: Since somnolence was a commonly reported adverse event associated with SEROQUEL treatment, patients should be advised of the risk of somnolence, especially during the 3-5 day period of initial dose titration. Patients should be cautioned about performing any activity requiring mental alertness, such as operating a motor vehicle (including automobiles) or operating hazardous machinery, until they are reasonably certain that SEROQUEL therapy does not affect them adversely.
Pregnancy: Patients should be advised to notify their physician if they become pregnant or intend to become pregnant during therapy.
Nursing: Patients should be advised not to breast feed if they are taking SEROQUEL.
Concomitant Medication: As with other medications, patients should be advised to notify their physicians if they are taking, or plan to take, any prescription or over-the-counter drugs.
Alcohol: Patients should be advised to avoid consuming alcoholic beverages while taking SEROQUEL.
Heat Exposure and Dehydration: Patients should be advised regarding appropriate care in avoiding overheating and dehydration.

Quetiapine hemifumarate Interactions

The risks of using SEROQUEL in combination with other drugs have not been extensively evaluated in systematic studies. Given the primary CNS effects of SEROQUEL, caution should be used when it is taken in combination with other centrally acting drugs. SEROQUEL potentiated the cognitive and motor effects of alcohol in a clinical trial in subjects with selected psychotic disorders, and alcoholic beverages should be avoided while taking SEROQUEL.

Because of its potential for inducing hypotension, SEROQUEL may enhance the effects of certain antihypertensive agents. SEROQUEL may antagonize the effects of levodopa and dopamine agonists.

The Effect of Other Drugs on Quetiapine hemifumarate

Phenytoin: Coadministration of quetiapine (250 mg tid) and phenytoin (100 mg tid) increased the mean oral clearance of quetiapine by 5-fold. Increased doses of SEROQUEL may be required to maintain control of symptoms of schizophrenia in patients receiving quetiapine and phenytoin, or other hepatic enzyme inducers (e.g., carbamazepine, barbiturates, rifampin, glucocorticoids). Caution should be taken if phenytoin is withdrawn and replaced with a non-inducer (e.g., valproate).

Divalproex: Coadministration of quetiapine (150 mg bid) and divalproex (500 mg bid) increased the mean maximum plasma concentration of quetiapine at steady state by 17% without affecting the extent of absorption or mean oral clearance.

Thioridazine: Thioridazine (200 mg bid) increased the oral clearance of quetiapine (300 mg bid) by 65%.

Cimetidine: Administration of multiple daily doses of cimetidine (400 mg tid for 4 days) resulted in a 20% decrease in the mean oral clearance of quetiapine (150 mg tid). Dosage adjustment for quetiapine is not required when it is given with cimetidine.

P450 3A Inhibitors: Coadministration of ketoconazole (200 mg once daily for 4 days), a potent inhibitor of cytochrome P4503A, reduced oral clearance of quetiapine by 84%, resulting in a 335% increase in maximum plasma concentration of quetiapine. Caution is indicated when SEROQUEL is administered with ketoconazole and other inhibitors of cytochrome P450 3A (e.g., itraconazole, fluconazole, and erythromycin).

Fluoxetine, Imipramine, Haloperidol, and Risperidone: Coadministration of fluoxetine (60 mg once daily); imipramine (75 mg bid), haloperidol (7.5 mg bid), or risperidone (3 mg bid) with quetiapine (300 mg bid) did not alter the steady-state pharmacokinetics of quetiapine.

Effect of Quetiapine hemifumarate on Other Drugs

Lorazepam: The mean oral clearance of lorazepam (2 mg, single dose) was reduced by 20% in the presence of quetiapine administered as 250 mg tid dosing.

Divalproex: The mean maximum concentration and extent of absorption of total and free valproic acid at steady state were decreased by 10 to 12% when divalproex (500 mg bid) was administered with quetiapine (150 mg bid). The mean oral clearance of total valproic acid (administered as divalproex 500 mg bid) was increased by 11% in the presence of quetiapine (150 mg bid). The changes were not significant

Lithium: Concomitant administration of quetiapine (250 mg tid) with lithium had no effect on any of the steady-state pharmacokinetic parameters of lithium.

Antipyrine: Administration of multiple daily doses up to 750 mg/day (on a tid schedule) of quetiapine to subjects with selected psychotic disorders had no clinically relevant effect on the clearance of antipyrine or urinary recovery of antipyrine metabolites. These results indicate that quetiapine does not significantly induce hepatic enzymes responsible for cytochrome P450 mediated metabolism of antipyrine.

Quetiapine hemifumarate Contraindications

SEROQUEL is contraindicated in individuals with a known hypersensitivity to this medication or any of its ingredients.

Manufacturers name:

  • Aphena Pharma Solutions - Tennessee, LLC
  • American Health Packaging
  • Breckenridge Pharmaceutical, Inc
  • DrReddys Laboratories Limited
  • Major Pharmaceuticals
  • AvKARE, Inc
  • REMEDYREPACK INC
  • BluePoint Laboratories
  • Lupin Pharmaceuticals, Inc
  • Sandoz Inc
  • Golden State Medical Supply, Inc
  • Cardinal Health
  • Citron Pharma LLC
  • Aurobindo Pharma Limited
  • Ascend Laboratories, LLC
  • Sun Pharma Global FZE
  • Alembic Pharmaceuticals Limited
  • NCS HealthCare of KY, Inc dba Vangard Labs
  • Bryant Ranch Prepack
  • Physicians Total Care, Inc
  • Torrent Pharmaceuticals Limited
  • Apotex Corp
  • Accord Healthcare Inc
  • Teva Pharmaceuticals USA Inc
  • Roxane Laboratories, Inc
  • DIRECT RX
  • Northstar Rx LLC
  • Unit Dose Services
  • TYA Pharmaceuticals
  • Preferred Pharmaceuticals, Inc
  • Clinical Solutions Wholesale
  • STAT Rx USA LLC
  • Proficient Rx LP
  • Jubilant Cadista Pharmaceuticals Inc
  • Mylan Pharmaceuticals Inc
  • McKesson Packaging Services a business unit of McKesson Corporation
  • Safecor Health, LLC

Generic name, Overdose, Half Life Quetiapine hemifumarate, Food Interactions, Chemical, etc..

Quetiapine hemifumarate see also Hibiscus flowers

Depression
Brand Names containing Quetiapine