A Cochrane review included 2 studies with a total of 228 subjects, comparing colchicine with placebo in acute gouty flares. In one study 0.5 mg colchicine was given every 2 hours until there was either complete relief of symptoms or toxicity and the total doses were not specified. In the other study a total of 4.8 mg colchicine was given over 6 hours. This study also included a low-dose colchicine arm (total 1.8 mg over 1 hour).
A greater proportion of people receiving high-dose colchicine experienced a 50% or greater decrease in pain from baseline up to 32 to 36 hours compared with placebo (RR 2.16, 95% CI 1.28 to 3.65; NNTB 4, 95% CI 3 to 12; 2 studies, n=124). Total number of adverse events (diarrhoea, vomiting or nausea) were greater in high-dose colchicine (RR 3.81, 95% CI 2.28 to 6.38; NNTH 2, 95% CI 2 to 5; 2 studies, n=124) than placebo. There was more people in the high-dose colchicine group who had a 50% or greater decrease in composite clinical score from baseline up to 32 to 36 hours than people in the placebo group (RR 10.50, 95% CI 1.48 to 74.38; 1 study, n=43).
Low-dose colchicine was more efficacious than placebo with respect to the proportion of people who achieve a 50% or greater decrease in pain from baseline to 32 to 36 hours (RR 2.43, 95% CI 1.05 to 5.64; NNTB 5, 95% CI 2 to 20; 1 study, n=103). There was no difference in adverse events (diarrhoea, nausea or vomiting) with low-dose colchicine compared to placebo (RR 1.24, 95% CI 0.55 to 2.79; 1 study, n=103). Proportion of people achieving 50% or greater decrease in pain from baseline up to 32 to 36 hours with high-dose colchicine was similar compared to low-dose (RR 0.87, 95% CI 0.56 to 1.36; 1 study, n=126). There were statistically significantly more adverse events in those who received high-dose colchicine versus low-dose group (RR 3.00, 95% CI 1.98 to 4.54; NNTH 2, 95% CI 2 to 3; 1 study, n=126). No studies comparing colchicine to NSAIDs or other active treatments such as glucocorticoids were found.
Comment: The quality of evidence is downgraded by imprecise results (few patients and outcome events) and by indirectness (no comparison with NSAIDs or glucocorticoids).