Moderate
Amitriptyline × Bisoprolol
Tricyclic antidepressants (TCA)×Selective beta-adrenergic blockers
Mechanism
Amitriptyline (TCA) causes orthostatic hypotension via α1-adrenergic blockade. Combined with bisoprolol: dizziness on standing. Anticholinergic effect of amitriptyline may aggravate bradycardia.
Symptoms
Lower blood pressure, postural dizziness, fatigue. Older patients: fall risk. With additional antihypertensives: bradycardia (pulse below 60/min).
Management
The combination is acceptable at low amitriptyline doses (25–50 mg). For neuropathic pain, gabapentin or pregabalin (no α1-blockade) is preferable. Check blood pressure standing and sitting at 1 week after start.
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.