MajorCalcium channel blockers (dihydropyridines)×Antiepileptics. Carboxamide derivatives
Updated · Methodology
Mechanism
Carbamazepine induces CYP3A4 – the main amlodipine metabolic route. Amlodipine plasma levels fall and the antihypertensive effect weakens.
Symptoms
Blood pressure returns to baseline or higher, headache. In angina, episodes reappear. Symptoms emerge 1–2 weeks after starting carbamazepine.
Management
During carbamazepine therapy, increase amlodipine 1.5- to 2-fold with blood pressure monitoring, or switch to an ACE-I (enalapril) or diuretic (hydrochlorothiazide). Alternative anticonvulsants without induction: levetiracetam, lamotrigine.
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.
Summary of a multi-drug list →
Medicine list: everything you take in one place →
Sources
- FDA: Tegretol (carbamazepine) prescribing information (2009)– ; DailyMed setid 8d409411-aa9f-4f3a-a52c-fbcb0c3ec053
- AEMPS: Ficha técnica: Amlodipino (nº registro 65461), sección 4.5 (2025)– AEMPS, CIMA, nº registro 65461, revisión 08/2025, sección 4.5