Drug-induced Urinary Retention: An Analysis of a National Spontaneous Adverse Drug Reaction Reporting Database

Background: Numerous drugs have been associated with urinary retention (UR), but updated information on drugs that may induce UR is limited. Objective: To evaluate drug-induced UR using the Italian spontaneous adverse drug reactions (ADRs) reporting database. Design, setting, and participants: We selected all suspected spontaneous reports of drug-induced UR collected into the Italian spontaneous reporting system (SRS) database from its inception to June 30, 2019. Outcome measurements and statistical analysis: The Mantel-Haenszel χ² test and the Mann-Whitney U test were performed for statistical comparisons of categorical and continuous variables, respectively. As a measure of disproportionality, we calculated the reporting odds ratios (RORs) with corresponding 95% confidence intervals using a statistical case/noncase methodology. Results and limitations: A total of 506 383 ADR reports were received in the Italian SRS database during the study period. Of these, 421 reports (0.1%) included UR-related ADRs, for a total of 497 suspected drugs. The median (interquartile range [IQR]) age of patients experiencing UR was 67 (47–77) yr. Overall, 174 (41.3%) ADR reports were considered serious. One-third of male patients experiencing UR suffered from benign prostatic hyperplasia, followed by diabetes mellitus (N = 58, 13.8%), and bladder-related disorders (N = 21, 5.0%). The median lag time between the start of drug treatment and UR onset was 7 (IQR 1–47.5) d. Overall, a statistically significant ROR was reported for 39 individual drugs, and for five (12.8%) of them (dapagliflozin, gabapentin, lithium, celecoxib, and piroxicam) UR was not described in their summary of product characteristics. Limitations include under-reporting and selective over-reporting of suspected ADRs and lacking information on the number of drug users. Conclusions: A disproportionality analysis identified five potentially new UR signals for dapagliflozin, gabapentin, lithium, celecoxib, and piroxicam, requiring further evaluation. Patient summary: In this analysis of the Italian spontaneous reporting system database, we found new urinary retention signals, requiring further evaluation, for dapagliflozin, gabapentin, lithium, celecoxib, and piroxicam.