Moderate
Amitriptyline × Captopril
Tricyclic antidepressants (TCA)×ACE inhibitor
Mechanism
Additive orthostatic hypotension via different mechanisms. Captopril (ACE-I) dilates vessels; amitriptyline blocks α1-adrenoceptors and reduces compensatory response.
Symptoms
Postural dizziness, syncope, fatigue. Older patients: fall and fracture risk.
Management
In older patients, check standing and sitting blood pressure 1–2 weeks after starting amitriptyline. For neuropathic pain, alternative: gabapentin or pregabalin.
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.