A 16% reduction (not statistically significant) in the risk of combined fatal or nonfatal myocardial infarction and sudden death has been reported. In this trial, lowering blood glucose with sulfonylurea therapy did not significantly effect cardiovascular complications. The largest of the trials, the United Kingdom Prospective Diabetes Study (UKPDS), has demonstrated that intensive therapy with sulfonylureas does not increase the risk of myocardial infarction or diabetes-related death when compared to conventional therapy. There are conflicting studies regarding the possible cardiovascular risks associated with the use of oral sulfonylurea antidiabetic agents like glipizide. In some cases, especially when patient has been receiving greater than 40 units of insulin daily, it may be advisable to consider hospitalization during the transition period. Several days should elapse between glipizide titration steps. Subsequent reductions in insulin dosage should depend on individual patient response.
Monitor blood glucose and other appropriate parameters 3 times daily or as indicated. For patients being treated with more than 20 units of insulin per day, the manufacturer recommends that the daily insulin dose be decreased 50% and glipizide be initiated with usual doses. For patients being treated with less than 20 units of insulin per day, the usual starting dose of glipizide may be used. SWITCHING FROM INSULIN: Some patients treated with insulin can be switched successfully to glipizide therapy. Daily doses more than 30 mg/day should be divided into 2 doses. Some patients not responding to once daily dosing may have better response with twice daily dosing. Max once daily dose: 15 mg PO once daily. Usual maintenance dosage: 10 to 15 mg PO once daily. Several days should elapse between dosage adjustments.
Dosage adjustments should be in increments of 2.5 to 5 mg. Geriatric patients or those patients at risk for hypoglycemia may be started on 2.5 mg/day. Initially, 5 mg PO once daily given 30 minutes before breakfast.