Rosiglitazone: a new therapy for Type 2 diabetes

Rosiglitazone (Avandiatrade mark) is a new generation thiazolidinedione used in the treatment of Type 2 diabetes. As with other thiazolidinediones, it binds to the gamma-isoform of the peroxisome proliferator-activated receptor (PPAR), a nuclear hormone receptor. Subsequent to PPAR-gamma activation, rosiglitazone increases insulin suppression of hepatic glucose output and increases peripheral glucose uptake in the muscles, thereby improving the glycaemic state of the individual. In rodent models of obesity and Type 2 diabetes, rosiglitazone has been shown to have positive effects in the main target organs responsible for the condition, namely the liver, pancreas, skeletal muscle and adipose tissue. These studies also suggest that rosiglitazone may help in preserving renal and pancreatic function that deteriorates in chronic hyperinsulinaemia. In clinical studies, rosiglitazone has been shown to be effective, safe and well-tolerated, not only when used as monotherapy, but also when used in combination with sulphonylureas, metformin or insulin. Unlike troglitazone, rosiglitazone is not metabolised via CYP3A4 and is thus unlikely to be subject to clinically important drug interactions. In addition, no evidence of hepatotoxicity has been associated with rosiglitazone to date. Rosiglitazone should therefore be strongly considered as part of the overall management of Type 2 diabetes.