atorvastatin and cyclosporine

Cyclosporine inhibits the OATP1B1 transporter in the liver that mediates hepatic uptake of atorvastatin, and also inhibits CYP3A4, the enzyme responsible for atorvastatin metabolism. This reduces clearance and increases plasma concentrations of atorvastatin and its active metabolites.

Elevated atorvastatin levels increase the risk of dose-dependent myopathy, including muscle pain, weakness, and rhabdomyolysis, which can lead to acute kidney injury and death. The interaction is clinically significant; patients may experience symptoms within weeks of starting therapy.

Avoid co-prescription where possible. If concurrent use is unavoidable, use the lowest recommended atorvastatin dose (e.g., 10 mg daily) and monitor for muscle symptoms and creatine kinase levels. Advise the patient to report unexplained muscle pain or weakness.

Well established through pharmacokinetic studies and case reports; cyclosporine increases atorvastatin AUC several-fold. Regulatory guidelines recommend dose adjustment.