Interactions médicamenteuses avec la colchicine, les contre-indications sont-elles bien respectées ? Étude descriptive des prescriptions en Bretagne à partir des données de l’Assurance maladie

Abstract

Although the French Health Authority "ANSM" widely informed healthcare professionals about the risk factors for colchicine overdose, its impact and suitable dosages, cases of potentially fatal preventable overdose continue to be reported in France. Using the French National Health Insurance of the Brittany area, we quantified the proportion of prescriptions presenting an absolute drug contraindication (CI) to colchicine (according to the ANSM Drug Interactions "Thesaurus") and its impact in terms of hospitalisation. Between 2013 and 2016, nearly 77,000 patients (mean age, 66±15 years) were reimbursed for at least one colchicine-based drug (Colchimax®, Colchicine Opocalcium®), representing nearly 205,000 prescriptions. General practitioners were the main prescribers (93%). Among the prescriptions, 0.5% had absolute IC with colchicine: in 51% of cases with pristinamycin, followed by azithromycin (15.6%), clarithromycin (15.2%) and roxithromycin (11.9%). In the 15 days following the simultaneous prescription of colchicine and a contraindicated drug, 53 hospital stays were recorded. However, using only the primary diagnosis of hospitalization was not sufficiently relevant to conclude that there was no potential overdose of colchicine. Over the study period, the Thesaurus contained inconsistencies that confused clinicians: mention of absolute IC with colchicine in the "macrolide" and "pristinamycin" sections but not in the sections of 'potent CYP inhibitors' or macrolide class molecules. Overall, very few prescriptions included absolute IC with colchicine. Regular training and information of healthcare professionals remains essential to limit the risk of colchicine overdose and to remind them of the potentially fatal consequences.