Below is a transcript of the latest statement (December 2008) published on Diabetes Care about the role of sulfonylureas in the medical management of hyperglycemia in type 2 diabetes.
Sulfonylureas lower glycemia by enhancing insulin secretion (see mechanism of action). In terms of efﬁcacy, they appear to be similar to metformin, lowering A1C levels by 1.5 percentage points (26,49). The major adverse side effect is hypoglycemia, which can be prolonged and life threatening, but such episodes, characterized by a need for assistance, coma, or seizure, are infrequent. However, severe episodes are relatively more frequent in the elderly.
Chlorpropamide and glibenclamide (known as glyburide in the U.S. and Canada), are associated with a substantially greater risk of hypoglycemia than other second-generation sulfonylureas (gliclazide, glimepiride, glipizide, and their extended formulations), which are preferable (Table 1) (53,54). In addition, weight gain of 2 kg is common following the initiation of sulfonylurea therapy.
Although the onset of the glucose lowering effect of sulfonylurea monotherapy is relatively rapid compared with, for example, the thiazolidinediones (TZDs), maintenance of glycemic targets over time is not as good as monotherapy with a TZD or metformin (55). Sulfonylurea therapy was implicated as a potential cause of increased CVD mortality in the University Group Diabetes Program (UGDP) study (56). Concerns raised by the UGDP that sulfonylureas, as a drug class, may increase CVD mortality in type 2 diabetes were not substantiated by the UKPDS or ADVANCE study (6,12). The glycemic beneﬁts of sulfonylureas are nearly fully realized at half-maximal doses, and higher doses should generally be avoided.