Rhabdomyolysis in a patient treated with colchicine and atorvastatin

OBJECTIVE: To report a case of severe rhabdomyolysis that developed after administration of atorvastatin to a patient receiving regular colchicine treatment. CASE SUMMARY: A 45-year-old man with nephrotic syndrome and amyloidosis presented with dyspnea, altered mentation, and severe fatigue. He had been taking colchicine 1.5 mg/day for amyloidosis for 3 years without adverse effects. Atorvastatin 10 mg/day was prescribed for hypercholesterolemia one month prior to admission. After 2 weeks of atorvastatin treatment, he began to experience myalgia and reduced muscle strength. The creatinine and creatine kinase concentrations on admission were 8.1 mg/dL and 9035 U/L, respectively. The patient was diagnosed with rhabdomyolysis with the findings of myoglobinuric, oliguric acute renal failure, and more than 50-fold elevated creatine kinase concentration. His muscle strength improved after withdrawal of atorvastatin and colchicine. However, he died because of nosocomial pneumonia that developed during his hospital stay. The Naranjo probability scale indicated that atorvastatin and colchicine were probable causes of rhabdomyolysis. DISCUSSION: Atorvastatin and colchicine have well-known myotoxic adverse effects. Despite atorvastatin's proven safety, its use with certain drugs, such as colchicine, makes it a potential myotoxic drug. This might be because concomitant administration of P-glycoprotein substrates, such as statins, and colchicine, which is a P-glycoprotein inhibitor, modifies pharmacokinetics by increasing bioavailability and organ uptake of the substrates, leading to more adverse reactions and toxicities. CONCLUSIONS: We recommend checking the creatine kinase level one week after prescribing 2 or more potentially myotoxic drugs concomitantly, after dose increase of a myotoxic drug, or after prescribing a new drug to a patient already using other myotoxic agents.