Chemical similarities are present among sulfonamides, sulfonylureas, carbonic anhydrase inhibitors, thiazides, and loop diuretics (except ethacrynic acid). Use in patients with sulfonamide allergy is specifically contraindicated in product labeling, however, a risk of cross-reaction exists in patients with allergy to any of these compounds; avoid use when previous reaction has been severe.
The extended release formulation consists of drug within a nondeformable matrix; following drug release/absorption, the matrix/shell is expelled in the stool. The use of nondeformable products in patients with known stricture/narrowing of the GI tract has been associated with symptoms of obstruction. Avoid use of extended release tablets (Glucotrol® XL) in patients with severe gastrointestinal narrowing or esophageal dysmotility.
Product labeling states oral hypoglycemic drugs may be associated with an increased cardiovascular mortality as compared to treatment with diet alone or diet plus insulin. Data to support this association are limited, and several studies, including a large prospective trial (UKPDS) have not supported an association.
Cardiovascular: Edema, syncope
Central nervous system: Anxiety, depression, dizziness, headache, insomnia, nervousness
Dermatologic: Rash, urticaria, photosensitivity, pruritus
Endocrine & metabolic: Hypoglycemia, hyponatremia, SIADH (rare)
Gastrointestinal: Anorexia, nausea, vomiting, diarrhea, epigastric fullness, constipation, heartburn, flatulence
Hematologic: Blood dyscrasias, aplastic anemia, hemolytic anemia, bone marrow suppression, thrombocytopenia, agranulocytosis
Hepatic: Cholestatic jaundice, hepatic porphyria
Neuromuscular & skeletal: Arthralgia, leg cramps, myalgia, tremor
Ocular: Blurred vision
Renal: Diuretic effect (minor)
Miscellaneous: Diaphoresis, disulfiram-like reaction
Postmarketing and/or case reports: Abdominal pain
Anabolic steroids may increase hypoglycemic effect; monitor blood glucose.
ACE inhibitors may increase hypoglycemic effect; monitor blood glucose.
Beta-blockers decrease hypoglycemic effect, mask most hypoglycemic symptoms, decrease glycogenolysis; avoid use in diabetics with frequent hypoglycemic episodes.
Cholestyramine decreases glipizide's absorption; separate administration times.
Corticosteroids cause hyperglycemia; adjustment of hypoglycemic agent may be necessary.
Cyclosporine serum concentration is increased; monitor cyclosporine levels and renal function.
CYP2C8/9 inducers: May decrease the levels/effects of glipizide. Example inducers include carbamazepine, phenobarbital, phenytoin, rifampin, rifapentine, and secobarbital.
CYP2C8/9 inhibitors: May increase the levels/effects of glipizide. Example inhibitors include delavirdine, fluconazole, gemfibrozil, ketoconazole, nicardipine, NSAIDs, pioglitazone, and sulfonamides.
Ethanol (large amounts) decreases hypoglycemic effect; avoid concurrent use; rare disulfiram reaction.
H2 antagonists, antacids, oral sodium bicarbonate may increase the hypoglycemic effect; monitor glucose response.
Rifampin may decrease hypoglycemic effects of glipizide; monitor blood glucose.
Tacrolimus serum concentrations may be increased; monitor tacrolimus serum concentrations and renal function.
Ethanol: Caution with ethanol (may cause hypoglycemia or rare disulfiram reaction).
Food: A delayed release of insulin may occur if glipizide is taken with food. Immediate release tablets should be administered 30 minutes before meals to avoid erratic absorption.
Herb/Nutraceutical: Caution with chromium, garlic, gymnema (may cause hypoglycemia).
Onset of action: Peak effect: Blood glucose reductions: 1.5-2 hours
Duration: 12-24 hours
Absorption: Delayed with food
Protein binding: 92% to 99%
Metabolism: Hepatic with metabolites
Half-life elimination: 2-4 hours
Excretion: Urine (60% to 80%, 91% to 97% as metabolites); feces (11%)
Immediate release tablet: Maximum recommended once-daily dose: 15 mg; maximum recommended total daily dose: 40 mg
Extended release tablet (Glucotrol® XL): Maximum recommended dose: 20 mg
When transferring from insulin to glipizide:
Current insulin requirement
Current insulin requirement >20 units: Decrease insulin by 50% and initiate glipizide at usual dose; gradually decrease insulin dose based on patient response. Several days should elapse between dosage changes.
Elderly: Initial: 2.5 mg/day; increase by 2.5-5 mg/day at 1- to 2-week intervals
Dosing adjustment/comments in renal impairment: Clcr<10 mL/minute: Some investigators recommend not using
Dosing adjustment in hepatic impairment: Initial dosage should be 2.5 mg/day
Fasting blood glucose: <120 mg/dL
Glycosylated hemoglobin: <7%
Tablet (Glucotrol®): 5 mg, 10 mg
Tablet, extended release: 5 mg, 10 mg
(Glucotrol® XL): 2.5 mg, 5 mg, 10 mg
Alexander RW, "Prolonged Hypoglycemia Following Acetohexamide Administration,"Diabetes, 1966, 15(5):362-4.
"A Study of the Effects of Hypoglycemia Agents on Vascular Complications in Patients With Adult-onset Diabetes. VI. Supplementary Report on Nonfatal Events in Patients Treated With Tolbutamide. The University Group Diabetes Program,"Diabetes, 1976, 25(12):1129-53.
Berelowitz M, Fischette C, Cefalu W, et al, "Comparative Efficacy of a Once-Daily Controlled-Release Formulation of Glipizide and Immediate-Release Glipizide in Patients With NIDDM,"Diabetes Care, 1994, 17(12):1460-4.
Brodows RG, "Benefits and Risks With Glyburide and Glipizide in Elderly NIDDM Patients,"Diabetes Care, 1992, 15(1):75-80.
Cowen DL, Burtis B, and Youmans J, "Prolonged Coma After Acetohexamide Ingestion,"JAMA, 1967, 201(2):141-2.
"Effect of Intensive Blood-Glucose Control With Metformin on Complications in Overweight Patients With Type 2 Diabetes (UKPDS 34). UK Prospective Diabetes Study (UKPDS) Group,"Lancet, 1998, 352(9131):854-65.
Frederick KA and Wang RY, "Delayed Hypoglycemia in a Child After Ingestion of a Single Glipizide Tablet,"Vet Hum Toxicol, 1994, 35:365.
Garratt KN, Brady PA, Hassinger NL, et al, "Sulfonylurea Drugs Increase Early Mortality in Patients With Diabetes Mellitus After Direct Angioplasty for Acute Myocardial Infarction,"J Am Coll Cardiol, 1999, 33(1):119-24.
Goran B, Bo B, Martin F, et al, "Glipizide-Induced Severe Hypoglycemia,"Acta Endocrinol (Copenh), 1981, 98(Suppl 245):13.
"Intensive Blood-Glucose Control With Sulphonylureas or Insulin Compared With Conventional Treatment and Risk of Complications in Patients With Type 2 Diabetes (UKPDS 33) UK Prospective Diabetes Study (UKPDS) Group,"Lancet, 1998, 352(9131):837-53.
Kilo C, Meenan A, and Bloomgarden Z, "Glyburide Versus Glipizide in the Treatment of Patients With Noninsulin-Dependent Diabetes Mellitus,"Clin Ther, 1992, 14(6):801-12.
Klamann A, Sarfert P, Launhardt V, et al, "Myocardial Infarction in Diabetic vs Nondiabetic Subjects. Survival and Infarct Size Following Therapy With Sulfonylureas (Glibenclamide),"Eur Heart J, 2000, 21(3):220-9.
Kradjan WA, Kobayashi KA, Bauer LA, et al, "Glipizide Pharmacokinetics: Effects of Age, Diabetes, and Multiple Dosing,"J Clin Pharmacol, 1989, 29(12):1121-7.
Kradjan WA, Takeuchi KY, Opheim KE, et al, "Pharmacokinetics and Pharmacodynamics of Glipizide After Once-Daily and Divided Doses,"Pharmacotherapy, 1995, 15(4):465-71.
Meinert CL, Knatterud GL, Prout TE, et al, "A Study of the Effects of Hypoglycemic Agents on Vascular Complications in Patients With Adult-Onset Diabetes. II. Mortality Results,"Diabetes, 1970, 19:789-830.
Nadel HL, "Formulary Conversion From Glipizide to Glyburide: A Cost-Minimization Analysis,"Hosp Pharm, 1995, 30:467-9, 472-4.
O'Keefe JH, Blackstone EH, Sergeant P, et al, "The Optimal Mode of Coronary Revascularization for Diabetics. A Risk-Adjusted Long-Term Study Comparing Coronary Angioplasty and Coronary Bypass Surgery,"Eur Heart J, 1998, 19(11):1696-703.
Rosenstock J, Corrao PJ, Goldberg RB, et al, "Diabetes Control in the Elderly: A Randomized, Comparative Study of Glyburide Versus Glipizide in Noninsulin Dependent Diabetes Mellitus,"Clin Ther, 1993, 15(6):1031-40.
"Standards of Medical Care for Patients With Diabetes Mellitus. American Diabetes Association,"Diabetes Care, 1994, 17(6):616-23.