Ombitasvir-Paritaprevir-Ritonavir Therapy in a Kidney Transplant Recipient With Chronic Hepatitis C Virus Genotype 1 Infection: A Case Report on the Importance of Considering Drug-Drug Interactions and Monitoring Cyclosporine Levels.

A 74-year-old Japanese man with a history of chronic hepatitis C and kidney transplant (KT) was administered pegylated-interferon plus ribavirin therapy. However, this therapy was ineffective. The patient was then hospitalized to receive ombitasvir (OBV) plus paritaprevir (PTV) plus ritonavir (r) antiviral combination therapy. He tested negative for the virus after 4 weeks, and completed 12 weeks of treatment. The patient ultimately achieved a sustained virological response after the 12 weeks of treatment. Cyclosporine (CyA) trough levels, during the OBV-PTV-r therapy, reached a peak within 5 days of initiating therapy, and increases in serum creatinine and total bilirubin were also observed. However, onset of irreversible nephropathy and hepatopathy were avoided by reducing the CyA dosage. The OBV-PTV-r therapy demonstrated a sufficient antiviral effect and could be safely administered postoperatively to patients having undergone KT. When a combination therapy with interferon-free, direct-acting antivirals is used in patients post-transplantation, consideration of drug-drug interactions with and monitoring CyA are of vital importance.