Troglitazone: Current Therapeutic Role in Type 2 Diabetes Mellitus

OBJECTIVE

To describe the role of troglitazone in the treatment of non-insulin-dependent diabetes mellitus.

METHODS

The potential mechanisms of action of the thiazolidinediones are outlined, and studies that have been conducted in animals and in humans are reviewed.

RESULTS

Although the precise mode of action of troglitazone, a thiazolidinedione, is unknown, this agent is an insulin sensitizer that has been shown to decrease fasting insulin, fasting plasma glucose, and blood pressure levels in humans. The effect of troglitazone is progressively greater over time; in several studies, the maximal action occurred as long as 12 weeks after initiation of treatment. The usual daily dose is 200 to 600 mg, and no dosage adjustment is necessary in patients with renal insufficiency. Adverse events, including fluid retention and hepatic dysfunction, may limit the utility of troglitazone in some clinical situations.

CONCLUSION

Both in monotherapy and in combination with sulfonylureas, insulin, or metformin, troglitazone has proved to be an effective agent for the treatment of type 2 diabetes mellitus.

Insulin resistance: current concepts

Insulin sensitivity varies greatly within the general population; factors contributing to this variability include genetic pre-disposition, obesity, unfavorable body fat distribution, and lack of physical activity. Impaired insulin sensitivity may lead to impaired glucose tolerance and, even in individuals with modest insulin deficiency, to the development of type 2 diabetes mellitus. Of equal concern in patients with impaired insulin sensitivity is the development of the insulin resistance syndrome, in which hypertension, dyslipidemia, and impaired glucose tolerance form a cluster of risk factors for cardiovascular disease. Treatment of insulin resistance includes metformin and the thiazolidinedione troglitazone. Both drugs have been shown to be effective in the treatment of insulin resistance, one of the central abnormalities in type 2 diabetes mellitus. The purpose of this study was to review the current understanding of insulin resistance and its implications for the treatment of type 2 diabetes mellitus. To do this, a MEDLINE search of the clinical literature was conducted and the content analyzed.