Effect of Colchicine on Clostridium Difficile Infection Incidence, Recurrence, and Severity

ObjectiveThe objective of this study was to determine the impact of colchicine use on the incidence, recurrence, and severity of Clostridium difficile infections (CDIs). DesignThis was a retrospective cohort analysis of data extracted from a large electronic medical records database. A secondary analysis using a self-controlled case series design was also used. SettingData from recorded patient prescriptions, inpatient and outpatient encounters, as well as laboratory tests and results during the study period were included. ResultsDuring fiscal years 2008 and 2009, a total of 77,202 patients treated in the United States Veterans Affairs system were prescribed and filled at least one 30-day prescription of colchicine. These were matched to 308,808 colchicine nonusers. A total of 1016 cases of CDI were developed during the study period in the cohort (users and nonusers). Overall, compared with nonusers, those who filled a colchicine prescription had a higher risk for experiencing a CDI event (adjusted relative risk, 1.44; 95% confidence interval, 1.15–1.97; P = 0.001) during the study period. An alternative self-controlled case series study design revealed similar findings (adjusted relative risk, 1.24; 95% confidence interval, 1.03–1.49; P = 0.02). ConclusionsColchicine use was associated with a statistically significant increased risk for CDI incidence and its severity (demarked by intensive care unit admission and associated death). This finding remained significant after controlling for confounders and was replicated through 2 different study designs. Furthermore, the enhanced risk applied to both initial incidence and recurrence. The risk was dose dependent, with a higher colchicine dose associated with greater CDI incidence.