Numerous interactions have been reported with the sulfonylureas, largely representing either pharmacokinetics interactions (due to the displacement of the antidiabetic plasma proteins or alteration in its metabolism or excretion) or pharmacological interactions with drugs having an independent effect on blood glucose. In the former class, most reports concern older sulfonylureas eg, chlorpropamide and tolbutamide, although the possibility of such reactions with newer drugs should be borne in mind.