Moderate
Bisoprolol × Haloperidol
Selective beta-adrenergic blockers×First-generation antipsychotics. Butyrophenone derivatives
Mechanism
Additive hypotension (haloperidol blocks α1-adrenoceptors) and QT prolongation risk (haloperidol is a known QT prolonger).
Symptoms
Lower blood pressure, postural dizziness, syncope. ECG: QT prolongation. Older patients: fall risk.
Management
Avoid the combination, especially parenteral haloperidol. Alternative antipsychotics with minimal α1 and QT effect: olanzapine or aripiprazole. For acute delirium: dexmedetomidine.
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.