Combined sulphonylurea-biguanide therapy for non-insulin dependent diabetics. Metabolic effects of glibenclamide and metformin or phenformin in newly diagnosed obese patients

Summary

Fasting, pre-prandial and post-prandial blood glucose levels and blood lactate, blood pyruvate, serum cholesterol, serum triglycerides and body weight were measured in 30 obese, newly diagnosed, non-insulin-dependent diabetics at the end of 4 subsequent periods of different regimens, each lasting for 5 days. In the first period, patients remained on free diet; in the second period, a hypocaloric diet (20 kcal/kg IBW) was followed; in the third period, glibenclamide (2.5 mg 3-times daily) was added to hypocaloric diet. During the last period, the patients were divided into two groups: Group A (15 patients) received, in addition to diet and glibenclamide, phenformin (25 mg 3-times daily) and Group B (15 patients) received, in addition to diet and glibenclamide, metformin (500 mg 3-times daily). Five similar patients served as controls and, at the end of the free-diet period, were put on hypocaloric diet and continued this regimen throughout the study period. The results showed that biguanides allowed a better glycaemic control when added to glibenclamide and that metformin, when compared to phenformin, had the same hypoglycaemic effect and a less marked hyperlactataemic action. Changes in body weight and triglycerides levels were similar in Groups A, B and controls, suggesting that the variations were a direct consequence of dietetic therapy. The serum total cholesterol level was significantly reduced when patients received metformin treatment and this is probably correlated with the reported hypolipidaemic effect of the drug. In view of these findings, it is suggested that metformin should be preferred to phenformin in association with glibenclamide when this drug alone fails to permit a good metabolic control.

Key Words::

• Metformin
• phenformin
• glibenclamide
• diabetes mellitus