Major
Carbamazepine × Ciclosporin
Antiepileptics. Carboxamide derivatives×Immunosuppressants. Calcineurin inhibitors
Mechanism
Carbamazepine induces CYP3A4 – the main cyclosporine metabolic route. Cyclosporine plasma levels drop sharply; immunosuppression weakens, raising transplant rejection risk.
Symptoms
Rejection symptoms depend on the organ: fever, graft tenderness, rising creatinine (kidney); jaundice and rising liver enzymes (liver); dyspnoea (heart, lungs). Symptoms appear 1–3 weeks after starting carbamazepine.
Management
Avoid the combination. Alternative anticonvulsants in transplant patients: levetiracetam, lamotrigine, or gabapentin (minimal CYP3A4 effect). If carbamazepine is unavoidable, measure cyclosporine levels 2–3 times weekly and increase the dose.