ModerateCalcium channel blockers (dihydropyridines)×First-generation antipsychotics. Butyrophenone derivatives
Updated · Methodology
Mechanism
Additive hypotension (haloperidol blocks α1-adrenoceptors) and sedation. Haloperidol prolongs QT; amlodipine does not contribute to QT.
Symptoms
Lower blood pressure, postural dizziness, fatigue. Older patients: fall risk.
Management
Avoid the combination, especially with parenteral haloperidol. Alternative antipsychotics with minimal α1-blockade: olanzapine or aripiprazole.
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.
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Sources
- FDA: Haloperidol tablet (Ajanta Pharma USA Inc.) – Prescribing Information (2020)– ; DailyMed setid 31e33656-2f53-49e6-9816-261ea2e6961a