Which statement best describes the interaction between ciclosporin and atorvastatin?

• A. Increases risk of liver injury
• B. No interaction
• C. Increases risk of atorvastatin toxicity
• D. Increases renal clearance of statins

Answer: (C)

Cyclosporin strongly inhibits enzymes and transporters that handle atorvastatin, leading to higher levels of the statin in the blood. Atorvastatin is mainly cleared by the liver through CYP3A4 metabolism and hepatic uptake via OATP1B1/1B3. When ciclosporin blocks these pathways, the drug isn’t cleared as efficiently, so plasma concentrations rise. That increased exposure raises the risk of statin-related toxicity, especially muscle toxicity like myopathy and, in rare cases, rhabdomyolysis.

So the interaction is best described as increasing the risk of atorvastatin toxicity. It’s not about no interaction, nor about increased renal clearance, and while liver injury can be a consequence of statin toxicity, the core issue here is higher statin exposure leading to toxicity.