Safety of Colchicine for Gout: A Ten-Year Survey of the Hong Kong Population

Abstract

Background Colchicine is an effective and inexpensive treatment for acute gout. It commonly causes diarrhoea, and may infrequently cause neutropenia and death. We previously reported the fatal interaction between colchicine and erythromycin (Hung et al. Clin Infect Dis. 2005). We therefore initiated a population-wide survey to study the prevalence and predictors of neutropenia and deaths associated with colchicine. Methods We searched the Hong Kong Hospital Authority Clinical Data Analysis and Reporting System for patients who developed neutropenia and received colchicine from Jan 2006 to Dec 2015. The database contains vital status, medical diagnoses, medication and admission records. Results During the 10-year period, 202,999 patients (mean age 68.6±15.6 years; 65% male) received colchicine (mean daily dose 1.2 mg and mean treatment duration 15.1 days). 89% of patients received colchicine for acute attack and 62% took it for prophylaxis. 137 (0.07%) non-cancer patients developed neutropenia, 21 of whom died (0.01% mortality among treated and 15% among those who developed neutropenia). We compared the 137 cases of colchicine-induced neutropenia with 137 randomly-selected controls. Patients with neutropenia had longer duration of prescription (cases vs. controls: 27.1±1.2 vs. 8.2±1.2; p<0.001), higher serum creatinine (150.1±17.8 vs. 109.5±6.6; p=0.034) and lower baseline white blood cell count (WBC) (7.28±0.40 vs. 10.45±0.97; p=0.001). The duration of treatment and baseline WBC level were predictors of colchicine-induced neutropenia (odds ratio for every 2.7 days of treatment, 2.1 [95%CI: 1.6-2.9]; odds ratio for every 1x109/L WBC: 0.88 [95%CI: 0.80-0.96]). Conclusions Colchicine-induced neutropenia is rare but life-threatening. This risk can be reduced by raising awareness, considering risk-benefit, avoiding interacting drugs and, as suggested by this study, recognizing at-risk patients and limiting treatment duration. Acknowledgments This study was supported by the Seed Funding Programme for Basic Research of the University of Hong Kong.