Evaluation of tolvaptan-associated hepatic disorder using different national pharmacovigilance databases.

Tolvaptan-associated hepatic disorder is a rare, but lethal adverse event; however, the precise risk and time of onset remain unclear. This study aimed to characterize the severity, time‑to‑onset, and outcomes of hepatic disorder based on patient age and sex. Patient data were acquired from the Japanese Adverse Drug Event Report database (JADER) and the JAPIC AERS database, which consists of the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS) processed by the Japan Pharmaceutical Information Center. Hepatic disorder was classified as severe or nonsevere. Tolvaptan use was associated with hepatic disorder in analyses using the FAERS [Severe hepatic disorder: reporting odds ratio (ROR) 4.93, 95% confidence interval (CI) 4.33‒5.61; information component (IC) 2.11, 95% CI 1.92‒2.29; nonsevere hepatic disorder: ROR 6.78, 95% CI 6.01‒7.65; IC 2.51, 95% CI 2.33‒2.68] and the JADER (severe hepatic disorder: ROR 4.21, 95% CI 3.57‒4.97; IC 1.86, 95% CI 1.63‒2.10; nonsevere hepatic disorder: ROR 4.27, 95% CI 3.68‒4.95; IC 1.83, 95% CI 1.62‒2.04). A time‑to‑onset analysis revealed that the median onset time was significantly longer in patients aged < 60 years compared with patients aged ≥ 60, regardless of the severity (FAERS: severe hepatic disorder 7 vs. 58 days, p < 0.0001; nonsevere hepatic disorder 8 vs. 52.5 days, p < 0.0001; JADER: severe hepatic disorder 9.5 vs. 32 days, p = 0.0017; nonsevere hepatic disorder 9 vs. 89 days, p < 0.0001). Severe outcomes were observed, regardless of the severity of hepatic disorder. Patients should be monitored for liver function based on age to prevent fatal outcomes.