[Clinically important effects of oral antidiabetic drug interactions]

Most of type 2. diabetic patients require medication for several concomitant diseases, most important being, hypertension, ischaemic heart disease, heart failure, dyslipidaemias, obesity. Thus the risk of drug interactions is important, particularly in elderly patients. Oral antidiabetic drugs include hypoglycaemic agents (sulphonylureas, meglitenides) and biguanides (metformin), alpha-glucosidase inhibitors, tiazolinidediones. Drug interactions with antihyperglycaemic agents can be divided into pharmacokinetic and pharmacodynamic interactions. Numerous drugs due to interactions enhance hypoglycaemic action of sulphonylureas, thus increase the risk of hypoglycaemia. Several drugs may cause impairment of glycaemic control through various mechanisms in diabetic patients treated with oral antidiabetic drugs. Currently the most controversial problem is safety of combination therapy with sulphonylurea and metformin, as several observations indicated that it can increase mortality from cardio-vascular causes.