Drug-induced lung disease adverse effect with Ledipasvir Acetonate/Sofosbuvir

BACKGROUND: Interferon and ribavirin have been used as therapeutic agents for chronic hepatitis C infection or C-compensated cirrhosis in the conventional treatment. Hepatitis C virus (HCV) -specific direct-acting antiviral agents that directly inhibit the growth process of HCV have been approved since 2011. However, in the early post-marketing vigilance phase of ledipasvir acetonate/sofosbuvir (LDV/SOF), there were reports of interstitial lung disease in 4 out of 32,700 cases with death in 1 case; the onset mechanism is unknown. CASE PRESENTATION: Treatment for hepatitis C was deemed to be necessary, and the patient was referred to our hospital. Oral administration of LDV/SOF was started. On day 8 of administration, a fever of 38–39 °C and coughing were observed followed by the gradual appearance of shortness of breath. As there was no improvement, the patient visited her primary care physician on day 16 of administration and the patient was brought urgently to our hospital on the same day. Blood tests and imaging tests were conducted at our hospital on the day of emergency transport; inflammatory response markers showed abnormal values, and sialylated carbohydrate antigen Krebs von den Lungen-6 was within the normal value range at 303 U/mL. Because the possibility of infection was low based on results of imaging and bronchoalveolar lavage, drug-induced lung disease was suspected, LDV/SOF administration was discontinued, and steroid administration was started. Following steroid pulse therapy, treatment with oral prednisolone tablets was gradually tapered. The patient’s symptoms were relieved and she was discharged. CONCLUSIONS: The patient’s medication history in this case indicated that there were no drugs taken before or after administration of LDV/SOF until the adverse reaction occurred, and there were no supplements or dietary supplements taken. Therefore, LDV/SOF has been proposed as the cause of the suspected adverse effect. Pharmacists should try to collect adverse effect reports to identify adverse effects early.