Postmarketing pharmacovigilance of adverse drug reactions: the case of rosiglitazone in Mexico

Abstract

Commercialization of rosiglitazone, an oral blood glucose-lowering drug of the thiazolidinedione class, was recently suspended in Europe and significantly restricted in the United States due to a possibly increased risk of ischemic heart disease; the drug is still being marketed in Mexico. This study was aimed to analyze the post-marketing occurrence of adverse drug reactions (ADRs) with rosiglitazone when used in combination therapy in Mexican Type 2 Diabetes patients. A prospective observational study was conducted at a primary health-care clinic in Mexico City. Eligible subjects were adult patients with Type 2 diabetes inadequately controlled with maximal doses of oral monotherapy, in which one of two combined therapeutic schemes was prescribed: rosiglitazone/glibenclamide (R/G), or rosiglitazone/metformin (R/M). Patients' blood pressure, weight, treatment adherence and occurrence of ADRs were monitored during a 6-month follow-up period. 174 patients received treatment with R/M or R/G (112 and 62 patients, respectively). At least one ADR was observed in about 75%, of patients. Prior to the end of the follow-up period, moderate ADRs leading to discontinuation of the treatment occurred in 29.5% and 14.5% of patients treated with R/M and R/G, respectively. The ADRs most frequently observed were peripheral edema and moderate weight gain. The use of rosiglitazone in combination with other oral anti-diabetic drugs was associated with a high frequency of ADRs in Mexican patients with Type 2 diabetes. Post-marketing studies are relevant to identify drug-associated risks to patients in clinical practice.