Cardiovascular effects of oral hypoglycaemic drugs

1. There is increasing evidence that sulfonylurea and biguanide oral hypoglycaemic drugs have cardiovascular effects and influence risk factors for cardiovascular disease in patients with non-insulin-dependent diabetes because of actions that are unrelated to alterations in glycaemic control. 2. While sulfonylureas may have anti-arrhythmic effects following myocardial ischaemia, there is concern that their action on vascular ATP-sensitive potassium channels may contribute to elevated blood pressure and enhanced vascular responsiveness. 3. In contrast to sulfonylureas, metformin (a biguanide) appears to reduce blood pressure and have beneficial effects on plasma lipoproteins by reducing low-density lipoprotein cholesterol and possibly increasing high-density lipoprotein cholesterol levels. 4. The pharmacological basis and clinical significance of these effects of sulfonylureas and biguanides require further investigation.