Objective: To evaluate the clinical utility of pioglitazone therapy in patients who previously received troglitazone.
Methods: We undertook an observational study involving patients with type 2 diabetes, who were originally treated with troglitazone and subsequently converted to pioglitazone therapy. Drug efficacy was evaluated by comparing baseline hemoglobin A1c (HbA1c) levels, weight, blood pressure, and lipid profiles (during troglitazone treatment) with corresponding values 6 months after final pioglitazone dose titration. Drug safety was evaluated by review of hepatic enzyme levels and documented reports of side effects.
Results: The study cohort consisted of 316 patients in whom pioglitazone therapy was initiated after they had received troglitazone for at least 1 year. Discontinuation of pioglitazone treatment subsequently occurred in 43 patients; in 7 additional patients, no follow-up occurred. We found no significant difference between baseline and follow-up mean HbA1c values. Aspartate aminotransferase levels did not significantly change after 6 months of pioglitazone therapy; however, alanine aminotransferase levels increased by a statistically significant 3.8 U/L (95% confidence interval, 2.6 to 4.9). Pioglitazone treatment was discontinued because of edema in 29 of the 309 evaluable patients (9.4%).
Conclusion: Pioglitazone was as effective as troglitazone in maintaining HbA1c levels. The hepatic safety of pioglitazone was also demonstrated.