Major
Carbamazepine × Simvastatin
Antiepileptics. Carboxamide derivatives×HMG-CoA reductase inhibitors (statins)
Mechanism
Carbamazepine induces CYP3A4 – the main simvastatin metabolic route. Simvastatin plasma levels fall 5- to 10-fold; lipid-lowering effect drops proportionally.
Symptoms
The patient feels nothing. Laboratory: LDL cholesterol and total cholesterol rise. In high cardiovascular risk patients, myocardial infarction and stroke risk increase.
Management
During carbamazepine therapy, increase simvastatin 2- to 3-fold with lipid profile and creatine kinase monitoring, or switch to pravastatin/rosuvastatin (metabolism less CYP3A4-dependent). 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.