Glipizide Dosage and Management for Type 2 Diabetes Mellitus
The recommended dosage of glipizide for type 2 diabetes mellitus is to start with 5 mg once daily given approximately 30 minutes before breakfast, with titration in increments of 2.5-5 mg based on blood glucose response, up to a maximum recommended once-daily dose of 15 mg or a total daily maximum of 40 mg if divided. 1
Initial Dosing and Administration
- Standard initial dose: 5 mg once daily, taken approximately 30 minutes before breakfast 1
- Special populations: For elderly patients, debilitated or malnourished patients, and those with liver disease, start with 2.5 mg 1
- Timing: Administer approximately 30 minutes before a meal to achieve the greatest reduction in postprandial hyperglycemia 1
- Administration with food: Unlike some other medications, glipizide absorption is affected by food, so proper timing before meals is important 2
Dose Titration and Maintenance
- Titration increments: 2.5-5 mg based on blood glucose response 1
- Titration interval: Allow at least several days between dose adjustments 1
- Maximum dosing:
- Maintenance regimen: Some patients may be effectively controlled on a once-daily regimen, while others show better response with divided dosing 1
Dosing in Special Populations
- Renal impairment: Initial and maintenance dosing should be conservative to avoid hypoglycemic reactions 1
- Hepatic impairment: Start with lower doses (2.5 mg) and use conservative maintenance dosing 1
- Elderly patients: Start with 2.5 mg and titrate cautiously 1
Formulations Available
- Immediate-release: Available in 5 mg, 10 mg doses 3
- Extended-release (GITS): Available in 5 mg, 20 mg doses 3
Monitoring and Follow-up
- Blood glucose monitoring: Regular monitoring of blood glucose is essential to determine:
- Minimum effective dose
- Primary failure (inadequate lowering at maximum dose)
- Secondary failure (loss of response after initial effectiveness) 1
- HbA1c monitoring: Glycosylated hemoglobin levels are valuable in monitoring response to therapy 1
- Follow-up interval: Assess glycemic response after 3 months on the maximum tolerated dose
Transitioning Between Medications
From insulin to glipizide:
- For patients on ≤20 units insulin daily: Insulin may be discontinued and glipizide started at usual dosages 1
- For patients on >20 units insulin daily: Reduce insulin by 50%, start glipizide at usual dosages, and make subsequent insulin reductions based on response 1
- During insulin withdrawal: Monitor urine for sugar and ketone bodies at least three times daily 1
- Consider hospitalization for transition in patients on >40 units insulin daily 1
From other oral hypoglycemics:
- No transition period necessary when transferring from other sulfonylureas to glipizide 1
- When switching from longer-acting sulfonylureas (e.g., chlorpropamide), observe carefully for 1-2 weeks for hypoglycemia due to potential overlapping effects 1
Drug Interactions and Precautions
- When coadministered with colesevelam, glipizide should be given at least 4 hours prior to colesevelam 1
- Hypoglycemia is a potential adverse effect, particularly in elderly, debilitated, or malnourished patients and those with renal or hepatic impairment 1
Place in Therapy
- Glipizide is a second-generation sulfonylurea that can be used as monotherapy or in combination with other agents for type 2 diabetes 3
- According to the American Diabetes Association standards, if metformin monotherapy does not achieve HbA1c targets after 3 months, a second agent should be added, which could include sulfonylureas like glipizide 3
- The choice of medication should be based on patient characteristics, disease factors, drug properties, and patient preferences 3
By following these dosing recommendations and monitoring guidelines, glipizide can be effectively used to manage hyperglycemia in patients with type 2 diabetes mellitus, with appropriate adjustments for special populations to minimize the risk of adverse effects, particularly hypoglycemia.