Please note that it has not been updated and that more recent literature may have become available since it was written. It has a favorable safety profile, with an incidence of extrapyramidal symptoms and changes in prolactin levels no different from placebo across the dosage range. 2-4 Unlike clozapine, quetiapine does not cause significant hematological effects. Quetiapine is rapidly absorbed after oral administration and extensively metabolized in the liver by the cytochrome P-450 enzyme system.
Urinary excretion is the main route of elimination of the drug.
No clinically significant drug interactions have been reported for quetiapine to date, but increased doses of quetiapine may be required if drugs that induce hepatic enzymes are used concurrently. Although no dosage adjustments are required, caution should be used when administering quetiapine with drugs that are potent inhibitors of the CYP3A4 enzyme. Somnolence, headache, dizziness, and weight gain are the most common adverse effects reported with quetiapine. In comparative trials with haloperidol, extrapyramidal symptoms occurred less frequently in the quetiapine treated groups. Quetiapine is safe and effective in treating the symptoms of schizophrenia.