What is the recommended dosing for glipizide (sulfonylurea) in adults with impaired glucose regulation?

Glipizide Dosing for Adults with Impaired Glucose Regulation

The recommended initial dosing for glipizide in adults with impaired glucose regulation is 5 mg once daily, given approximately 30 minutes before breakfast, with conservative initial dosing of 2.5 mg daily recommended for elderly patients or those with liver disease. 1

Initial Dosing

• Initial dose should be 5 mg once daily, administered approximately 30 minutes before breakfast to achieve the greatest reduction in postprandial hyperglycemia 1
• For elderly patients, debilitated or malnourished patients, and patients with impaired renal or hepatic function, a more conservative initial dose of 2.5 mg is recommended to avoid hypoglycemic reactions 1
• Glipizide should be administered at least 4 hours prior to colesevelam if these medications are used concurrently 1

Dose Titration

• Dosage adjustments should be made in increments of 2.5-5 mg, based on blood glucose response 1
• Allow at least several days between titration steps to properly assess glycemic response 1
• If response to a single dose is not satisfactory, dividing that dose may prove more effective 1
• The maximum recommended once-daily dose is 15 mg 1
• Doses above 15 mg should ordinarily be divided and given before meals of adequate caloric content 1
• The maximum recommended total daily dose is 40 mg 1

Renal Considerations

• For patients with renal impairment (CrCl 30-50 mL/min/1.73 m²), initiate conservatively at 2.5 mg once daily and titrate slowly to avoid hypoglycemia 2
• Patients with renal impairment are at higher risk of developing severe hypoglycemia (odds ratio 4.0 compared to those without renal impairment) 3

Maintenance Dosing

• Some patients may be effectively controlled on a once-daily regimen, while others show better response with divided dosing 1
• Total daily doses above 15 mg should ordinarily be divided 1
• Total daily doses above 30 mg have been safely given on a twice-daily basis to long-term patients 1

Important Considerations and Cautions

• Increasing the glipizide dose to more than 10 mg once daily produces little or no additional benefit and may reduce beta-cell function 4
• Patients with renal impairment and those taking multiple medications (particularly diuretics and benzodiazepines) are at increased risk of severe hypoglycemia 3
• Severe hypoglycemia can occur with glipizide treatment, particularly in elderly patients (mean age 75 years in reported cases) 3
• Hypoglycemia can be prolonged or recurrent for up to 60 hours in some patients 3
• Blood glucose must be monitored periodically to determine the minimum effective dose, detect primary failure (inadequate glucose lowering at maximum dose), and detect secondary failure (loss of response after initial effectiveness) 1
• Glycosylated hemoglobin levels are also valuable in monitoring response to therapy 1

Switching from Other Medications

• When transferring from longer half-life sulfonylureas (e.g., chlorpropamide), patients should be observed carefully for 1-2 weeks for hypoglycemia due to potential overlapping drug effects 1
• For patients on insulin whose daily requirement is 20 units or less, insulin may be discontinued and glipizide therapy begun at usual dosages 1
• For patients on insulin whose daily requirement is greater than 20 units, the insulin dose should be reduced by 50% when starting glipizide 1