Major
Ciclosporin × Rifampicin
Immunosuppressants. Calcineurin inhibitors×Antituberculous antibiotic
Mechanism
Rifampicin strongly induces CYP3A4 and P-glycoprotein. Cyclosporine plasma levels fall by 50–70%; immunosuppression is lost, raising transplant rejection risk.
Symptoms
Rejection symptoms depend on the organ: fever, graft tenderness, rising creatinine (kidney), jaundice (liver), dyspnoea (heart, lungs). Symptoms appear 1–3 weeks after starting rifampicin.
Management
Avoid the combination. Alternative anti-TB drug: rifabutin (weaker CYP3A4 induction) with cyclosporine dose titration. If rifampicin is unavoidable, raise cyclosporine 2- to 3-fold with trough (C0) twice weekly.