[Long-term effect of combination glibenclamide-insulin treatment in the secondary failure of sulfonylurea therapy--results of a one-year double blind study].

: The long-term efficacy of combined insulin-glibenclamide treatment was investigated in 79 secondary drug failure patients by means of a double-blind, randomized placebo-controlled study. During a one-year follow-up period the patients on insulin plus glibenclamide required significantly lower exogenous insulin doses. Coincidentally, C-peptide concentrations were significantly raised in the verum versus the placebo group. Additionally, the administration of glibenclamide resulted in a decreased level of hyperglycaemia during the first six months of the observation period. Glibenclamide withdrawal after six and again after twelve months of the combined therapy provoked a deterioration of glycaemic control, as well as a lowering of the C-peptide concentrations. The findings demonstrate a prolonged beneficial effect of the combined treatment, in contrast to the solely short-term effects predicted by numerous studies. The metabolic improvement must be ascribed in part to the beta-cytotropic effect of glibenclamide. Extrapancreatic pathways via receptor/postreceptor mechanisms cannot be excluded.