INS and Hypoglycemia: The recommendation to discontinue the sulphonylurea (glyburide) but not metformin after insulin combination therapy is started is based on some patients’ inability to adequately titrate the dose of bedtime NPH because of hypoglycaemia.43,44 It has been proposed that sulphonylureas can be continued for meals not covered by pre-prandial insulin using basal-bolus regimens.