Dosage Forms. Tablet: 25 mg, 50 mg, 100 mg, 200 mg, 300 mg, 400 mg; Tablet, Extended Release: 50 mg, 150 mg, 200 mg, 300 mg, 400 mg
Common FDA Label Indication, Dosing, and Titration.
1. Bipolar disorder or schizophrenia, therapy initiation: Adults, regular release, 50 mg po bid × 1 d, increase 50 mg per day × 3 d, may titrate to 800 mg/d; Adults, extended release, 300 mg po hs × 1 d, then 600 mg po hs × 1 d, may titrate to 800 mg/d; Children 10-17 y of age, regular release, 50 mg po × 1 d, then 100 mg po × 1 d, then 200 mg po × 1 d, then 300 mg po × 1 d, then 400 mg po × 1 d, may titrate to 600 mg/d
2. Bipolar disorder or schizophrenia, maintenance: Adults, regular release: 400-800 mg/d po; Adults, extended release, 400-800 mg/d po; Children 10-17 y of age, regular release, titrate to lowest effective dose
3. Major depressive disorder: Adults, extended release, 50 mg po daily hs, may titrate to 300 mg/d
Off-Label Uses. None
MOA. Quetiapine is an antagonist at multiple neurotransmitter receptors in the brain. It antagonizes serotonin 5HT1A and 5HT2, Dopamine D1 and D2, histamine H1, and adrenergic,1 and 2 receptors. Efficacy in schizophrenia and bipolar disorder is due to the antagonism of a combination of D2 and 5HT2 receptors. Quetiapine also has no affinity for cholinergic muscarinic and benzodiazepine receptors.
Drug Characteristics: Quetiapine
Medication Safety Issues: Quetiapine
Drug Interactions: Quetiapine
Adverse Reactions: Quetiapine
Efficacy Monitoring Parameters. Improvement in signs and symptoms of schizophrenia, manic or mixed episodes associated with bipolar disorder, depression.
Toxicity Monitoring Parameters. BP, FPG and CBC, eye examination at baseline and periodically during therapy; patients at high risk for suicide should be closely supervised.
Key Patient Counseling Points. Take with food but avoid alcohol. Avoid activities requiring mental alertness or coordination. Use caution with activities leading to an increased core temperature. Rise slowly from a sitting/supine position. Report signs/symptoms of hyperglycemia, bradycardia, arrhythmia, tardive dyskinesia, or neuroleptic malignant syndrome.
Clinical Pearls. Regular release may be switched to extended release at the equivalent total daily dose taken once daily; individual dosage adjustments may be required. Elderly patients with dementia-related psychosis taking quetiapine are at an increased risk of death compared to placebo.