L. S. Hermann

The short-term (2-12 weeks) antihyperglycaemic efficacy of metformin (M), glibenclamide (G), and their primary combination (MG) was assessed in a double-blind study including 165 unselected patients with Type 2 diabetes. Patients with diet failure were randomized to M, G or MG. The dose was titrated with a fasting blood glucose concentration (FBG) of < 6.7 mmol l-1 as the target, using at most six dose levels, the first three comprising increasing monotherapy (M or G) or low-dose primary combination (MGL), and the second three add-on therapies (M/G and G/M) and primary combination therapy escalated to high dose (MGH). Success rates were higher on MGL than on monotherapy. The difference in achieving acceptable control (FBG < or = 7.8 mmol 1(-1)) was 70% versus 51% (95% confidence interval 3-36%, p = 0.032). When the drugs were combined, a slightly greater FBG reduction (p = 0.026) was observed, at lower dosage (p = 0.013). The response could not be predicted from body weight, but depended upon initial FBG (p = 0.019) and meal-stimulated C-peptide (p = 0.007). FBG declined progressively with increasing doses of metformin, whereas glibenclamide exerted most of its effect at low dose. Primary combination therapy with metformin and sulphonylurea may be clinically useful.

AIM: To assess the adjunct effect of metformin to insulin in type 2 diabetes. METHODS: Obese and overweight type 2 diabetes patients treated with insulin for at least 1 year, and with poor glycaemic control (HbA1c > upper reference level + 2%), were included in a randomised, double-blind, placebo-controlled study. Patients were treated for 12 months with either metformin (850 mg b.i.d.) or placebo added to their usual insulin, which was stabilized during a 3-month placebo run-in period, but thereafter attempted to be unchanged. RESULTS: Thirty-seven patients were included. Two patients dropped out during run-in. There were no differences between the metformin (n = 16) and placebo (n = 19) group at baseline. Most patients received multiple insulin injections. Metabolic control was improved by addition of metformin. Mean change in HbA1c from baseline showed highly significant difference between groups at 3, 6, 9 and 12 months. Mean change (percentage units +/- s.d.) at 12 months was -1.1 +/- 0.7% vs. + 0.3 +/- 0.8% (p < 0.001) for HbA1c and -1.4 +/- 2.1 mmol/l vs. + 0.6 +/- 2.2 mmol/l (p = 0.025) for fasting blood glucose. Mean low density lipoprotein (LDL) cholesterol change differed slightly at 6 months, but not at 12 months. There were no changes in insulin dose, blood pressure, body weight, triglycerides, total- and high density lipoprotein (HDL) cholesterol, fibrinogen, C-peptide and laboratory safety variables, including serum B12. Combination therapy was well-tolerated with the same adverse event rate as insulin alone, but more patients with diarrhoea. CONCLUSION: Addition of metformin to insulin induced and maintained clinically significant and consistent long-term reduction of hyperglycaemia in obese, insulin-treated type 2 diabetes patients.

Metformin and glibenclamide were compared in a randomized, double-blind trial in patients with non-insulin-dependent diabetes mellitus (NIDDM) using a parallel group design. The study was performed in primary health care, and the main purpose was to assess combination therapy with the two drugs as primary treatment versus conventional oral therapy. After a 2 months diet period patients were randomized to commence treatment with either metformin, glibenclamide or the combination of both. Patients randomized to monotherapy received the alternative drug in addition if the maximal dose i.e. 3 g metformin or 14 mg glibenclamide was insufficient to normalize the fasting blood glucose concentration (FBG). Randomization and dose escalation occurred at FBG greater than or equal to 6.7 mmol/l. The titrated dose was continued for 6 months, whereafter placebo was given for 2 weeks. Seventy-two patients were randomized to either the metformin group (n = 38) or the glibenclamide group (n = 34). Fifty-six completed 6 months treatment, twenty-eight in each randomized group. Glycaemic control was unchanged after diet alone in all groups. The improvement during drug treatment was highly significant (p less than 0.001), mean FBG difference (+/- SEM) 3.2 +/- 0.4 mmol/l and mean HbA1c difference (+/- SEM) 1.5 +/- 0.2% (n = 56). There were no significant differences between patients treated solely with metformin (n = 16) and glibenclamide (n = 17) or between patients treated with a combination of glibenclamide added to metformin (n = 12) and metformin added to glibenclamide (n = 11).(ABSTRACT TRUNCATED AT 250 WORDS)