[Combined treatment of type-2 diabetics with insulin and glibenclamide after secondary drug failure. Double-blind, insulin-placebo-controlled crossover study].

A double-blind, placebo-controlled, crossover-therapy study was carried out using intraindividual comparisons on 18 type II diabetics. All patients were secondary drug failure patients and had been on insulin-glibenclamide combination therapy for periods of 1-14 months. On the last day of each of the 2-week-treatment periods (insulin-glibenclamide [verum phase] versus insulin-placebo [placebo phase]) the patients received a standard breakfast equivalent to 100 g glucose. Medication was given 30 minutes before the standard breakfast. The blood glucose level during insulin-glibenclamide therapy was 35-45 mg/dl below that during insulin-placebo treatment at all time points investigated. Correspondingly, the glucose excretion was reduced by about 40% during the verum phase. beta-Hydroxybutyrate in serum and urine and glycosylated haemoglobin (HbA1) measurements made during the verum phase were also significantly lower. As expected, the insulin level in serum showed no change. In contrast, C peptide concentrations were significantly raised by 15-40% during the verum phase. Combination therapy with insulin and glibenclamide produced therefore a marked improvement in the metabolic status of C peptide-positive patients classified as secondary drug failure patients to oral therapy.