Colchicine Drug Levels Not Predictive of Efficacy or Side Effects in Gout Flare Prevention
A new analysis of data from a randomized controlled trial has found that measuring colchicine plasma levels offers limited clinical value in predicting either the effectiveness of gout flare prophylaxis or the likelihood of adverse events. The results published in American College of Rheumatology, suggest that therapeutic drug monitoring (TDM) of colchicine may not be necessary in routine practice, even among older patients or those on concomitant statins.
“Our objective was to examine the relationship between colchicine plasma concentrations and clinical and demographic factors and to determine the relationship between colchicine concentrations and colchicine efficacy and colchicine-specific adverse events,” the authors stated.
The post hoc analysis drew from a 12-month trial of 200 patients with gout who were randomized to receive low-dose colchicine or placebo for the first 6 months while initiating allopurinol. Colchicine concentrations were measured at month three, both 30–80 minutes after dosing (peak) and just prior to dosing (trough). Investigators also assessed creatine kinase (CK) levels and recorded gout flares, adverse events, and serious adverse events throughout the study.
Of the 79 participants in the colchicine arm with pharmacokinetic data, multivariable analysis revealed that statin use and non-Māori/non-Pacific ethnicity were independently associated with higher trough levels. Age over 60 was linked to higher peak concentrations.
Interestingly, while both trough and peak colchicine concentrations were significantly higher in those who reported any adverse event between months four and six, the study found no association between colchicine levels and colchicine-specific adverse events, such as gastrointestinal symptoms or muscle-related issues. CK levels also remained unaffected across concentration levels.
“Trough or peak colchicine concentrations are not associated with gout flare prophylaxis efficacy. There is no consistent relationship between colchicine concentrations and colchicine-specific adverse events,” the authors concluded. “Although colchicine concentrations increase with concomitant statin use, this does not result in muscle-related adverse events. These findings indicate that colchicine therapeutic drug monitoring is of limited value in clinical practice.”
Reference
Stamp LK, Horne A, Mihov B, Drake J, Haslett J, Chapman P, Wright DFB, Frampton C, Dalbeth N. Colchicine concentrations and relationship With colchicine efficacy and adverse events: post hoc analysis of a randomized clinical trial of colchicine for gout flare prophylaxis. Arthritis Care Res (Hoboken). 2025 Sep;77(9):1157-1164. doi: 10.1002/acr.25548. Epub 2025 May 23.
