4 known interactions • 2 major • 2 moderate • 0 minor
Always disclose all medications to your healthcare providers — prescription medicines, OTC medications, vitamins, and herbal supplements. This list may not include every possible interaction. Use our Medicine Interaction Checker to screen your complete medication list.
Potentially life-threatening or causing permanent damage. Avoid combination.
May worsen condition or require dose adjustment. Monitor closely.
Usually limited clinical effect. Manage with routine monitoring.
CYP3A4 inhibitors (ketoconazole, ritonavir, erythromycin)
CYP3A4 inhibitors significantly increase quetiapine plasma levels, increasing sedation, QTc prolongation, and metabolic risks.
Management: Reduce quetiapine dose by up to 1/6 when used with strong CYP3A4 inhibitors.
CYP3A4 inducers (carbamazepine, phenytoin, rifampin)
Inducers dramatically reduce quetiapine levels (by up to 87%), potentially causing loss of antipsychotic efficacy.
Management: Increase quetiapine dose up to 5x when adding carbamazepine. Reduce back when inducer stopped.
CNS depressants / alcohol
Additive sedation and CNS depression.
Management: Avoid alcohol. Use with caution with other CNS depressants.
Antihypertensives
Additive hypotension (quetiapine blocks alpha-1 adrenergic receptors).
Management: Monitor blood pressure; advise patients to rise slowly from sitting/lying positions.
Always ask your pharmacist about potential interactions with food, alcohol, and supplements specific to Quetiapine. Some medicines have significant interactions with grapefruit juice, high-fat meals, dairy products, or vitamin K-rich foods.