Rationale. To date, liver transplantation is the most effective method of treating end-stage liver failure, and therefore this treatment has become widespread throughout the world. However, due to the improvement in the quality of transplant care and an increase in the long-term survival of patients, the development of concomitant pathology, which often requires medical treatment, is inevitably associated with a higher life expectancy of liver transplant recipients. Thus, in patients who underwent liver transplantation, there is. a significant increase in the incidence of dyslipidemia. However, a long-term immunosuppressive therapy in organ transplant patients can adversely modify the effect of the prescribed drugs, which requires careful monitoring and consideration of drug interactions.Purpose. Using a clinical example to demonstrate the importance of taking drug interactions into account in the treatment of patients after organ transplantation receiving immunosuppressive drugs.Material and methods. In the presented clinical case, a patient after orthotopic liver transplantation performed in 2005 underwent a staged treatment of cicatricial stricture of choledochal anastomosis in the S.P. Botkin City Clinical Hospital. During the following hospitalization, the patient complained of minor muscle pain when walking. At doctor's visit 3 weeks before hospitalization, a local physician prescribed therapy with atorvastatin 10 mg per day due to an increase in blood plasma cholesterol levels. The patient underwent removal of the self-expanding nitinol stent. During the follow-up examination, the patient had no evidence of an impaired bile outflow, however, muscle pain and weakness progressively increased, the rate of diuresis decreased, and in the biochemical analysis of blood there was an abrupt increase in the concentration of creatinine, aspartate aminotransferase, alanine aminotransferase. Atorvastatin was canceled, a diagnosis of acute non-traumatic rhabdomyolysis was established, treatment with hemodialysis and plasma exchange was started on 03/05/2020. The last session of renal replacement therapy was 03/30/20.Results. With the restoration of the diuresis rate, there was a spontaneous decrease in the level of creatinine to 170 μmol/L. The patient was discharged with satisfactory renal and hepatic function. The pain syndrome completely resolved. Conclusion. Drug interactions between atorvastatin and cyclosporine have resulted in acute rhabdomyolysis with life-threatening consequences. This once again confirms the importance of taking drug interactions into account when managing patients after solid organ transplantation.