Purpose: Long-term acetaminophen (APAP) use has poorly defined effects on renal function. We investigated these effects using a real-world database.
Methods: We used a database of health data routinely collected from 185 hospitals serving 20 million patients in Japan. Individuals with chronic pain were selected for the study. The primary outcome was the change in renal function, as measured by 1/serum creatinine (SCr) during the postindex period.
Results: After excluding individuals who did not meet the inclusion criteria, 241,167 patients were included in the analysis (median age 79.0, range 65-101 years; 111,252 were men). APAP was prescribed significantly more frequently to patients with a low renal function (P < 0.001). The annual changes in 1/SCr median and interquartile range (IQR) were - 0.038 (- 0.182 to 0.101) in patients receiving APAP, - 0.040 (- 0.187 to 0.082) in patients receiving non-steroidal anti-inflammatory drugs (NSAIDs), and - 0.025 (- 0.142 to 0.079) in nonmedicated control patients (P < 0.001). These changes were not significantly different among patients with a low renal function, with 0.003 (- 0.066 to 0.113) in the APAP group, 0.000 (- 0.089 to 0.090) in the NSAID group, and - 0.009 (- 0.086 to 0.089) in the control group (P = 0.327).
Conclusion: Physicians tended to select APAP for individuals with a low renal function. The annual changes in 1/SCr were significantly different based on APAP and NSAID use or no analgesia, but the differences were not significant among patients with a low renal function. Overall, long-term use of APAP does not appear to exacerbate the renal function in a clinical setting.
Keywords: Acetaminophen; Longitudinal study; Real-world database; Renal function.