Oral hypoglycaemics - a review of the evidence.

BACKGROUND

The range of oral hypoglycaemic agents (OHAs) has increased from one insulin sensitiser (metformin) and one class of insulin secretagogues (sulphonylureas) with the addition of further class of insulin secretagogues (glitinides), a further class of insulin sensitisers (glitazones) and two new classes: an alpha glycosidase inhibitor and glucagon-like peptide agents. Recent data has influenced the recommended sequence and usage of OHAs and glycaemic targets.

OBJECTIVE

This article reviews the recent evidence in type 2 diabetes about the pros and cons of oral hypoglycaemic agents and the benefits and costs of intensive glycaemic control. It suggests a stepwise approach to glycaemic control with OHAs according to the evidence base currently available.

CONCLUSIONS

Before 2008, the recommended glycaemic management was healthy lifestyle, metformin and sulphonylurea if tolerated, then rosiglitazone or insulin. Pioglitazone could be used with insulin therapy but not as triple therapy. In 2007 and 2008 data about glitazones demonstrated a potential increased risk of myocardial infarction with rosiglitazone and increased risk of heart failure, peripheral fractures and macular oedema with both pioglitazone and rosiglitazone. In 2009 a new class of hypoglycaemic agents, glucagon-like peptide 1 agents, became available. Three trials published in 2009 failed to show a statistically significant reduction in cardiovascular events with intensive glycaemic management compared to conventional management. The current recommended target for HbA1c is <7% but higher or lower targets may be appropriate for individual patients.