Possible drug-drug interactions among elderly patients receiving antiviral therapy for chronic hepatitis B

Aim To identify possible drug-drug interactions in patients taking medications for other comorbidities while on antiviral therapy for chronic hepatitis B. Methods The study enrolled patients with chronic hepatitis B aged >= 60 years who were treated with antiviral therapy in five hospitals in Turkey between January 1 and March 1, 2023. The Lexicomp (R) Drug Interactions program was used to identify possible drug-drug interactions. Results The study included 213 patients (119 [55.9%] men). The mean age was 68.5 years. A potential drug- drug interaction was identified in 112 patients (52.6%). The most common type of interaction was type C ("follow the treatment") (71.54%). The number of potential drug-drug interactions increased with an increase in the number of drugs used by the patients. A robust and affirmative correlation was observed between the number of medications used and the number of possible drug-drug interactions (r = 0.791, P < 0.001). Adverse interactions (interactions of types C and D, 3.7% of cases) were limited to patients receiving tenofovir disoproxil fumarate. Conclusion Nonsteroidal anti-inflammatory medications should be used cautiously in elderly patients with chronic hepatitis B treated with tenofovir disoproxil fumarate due to the increased risk of renal toxicity.