Moderate
Amlodipine × Quetiapine
Calcium channel blockers (dihydropyridines)×Atypical antipsychotics
Mechanism
Additive hypotension. Quetiapine blocks α1-adrenoceptors; amlodipine dilates vessels.
Symptoms
Lower blood pressure, postural dizziness, fatigue. Older patients: fall risk.
Management
The combination is acceptable at low quetiapine doses (≤300 mg/day). Check blood pressure 1–2 weeks after start. In older patients, olanzapine or aripiprazole (less α1-blockade) is preferable.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.