Influence of food on the disposition of the antidiabetic drug metformin in diabetic patients at steady-state.

The effect of food on the bioavailability of the antidiabetic drug metformin (Glucophage, Lipha Laboratories) was investigated in patients at steady-state. Seventeen diabetic patients (5 males and 12 females) treated with a long-term metformin therapy received their morning dose after an overnight fasting or after each of four types of breakfast: low protein, low fat, low carbohydrate or standard. Mean (+/- SD) and median areas under the serum concentration curves (AUC), maximum concentrations (Cmax) and time to reach the Cmax (Tmax) were calculated. Compared to fasting conditions, AUC and Cmax for metformin were bioequivalent after the four types of breakfast except the low fat (high carbohydrate) diet which had results slightly reduced (90% CI = [0.76-0.90]). The intraindividual variability was calculated and found to be lower than the interindividual variability.