Long-term safety and efficacy of glipizide.

We studied the effect of long-term glipizide therapy in a small group of closely monitored patients. Fasting plasma glucose, glucose tolerance, glucose-stimulated insulin secretion, and insulin sensitivity were measured on multiple occasions throughout the investigation. Our observations show that glipizide therapy is effective in certain patients with noninsulin-dependent diabetes mellitus over a prolonged time period. The major effect of the drug appears to be mediated by its alteration of insulin sensitivity, but glipizide also causes a sustained increase in glucose-stimulated insulin secretion in most patients.