How often should Glipizide be taken?

Glipizide Dosing Frequency: Once or Twice Daily

Glipizide can be taken once daily for extended-release (XL) formulation with a maximum of 20 mg daily, while immediate-release (IR) formulation can be taken once or twice daily depending on dose and glycemic control, with a maximum of 40 mg daily. 1, 2

Immediate-Release Glipizide Dosing

• Initial recommended dose is 5 mg given approximately 30 minutes before breakfast 1
• Geriatric patients or those with liver disease should start with 2.5 mg 1
• Dosage adjustments should be made in increments of 2.5-5 mg based on blood glucose response 1
• The maximum recommended once-daily dose is 15 mg 1
• Doses above 15 mg should be divided and given before meals 1
• The maximum total daily dose is 40 mg 1
• Some patients may be effectively controlled on a once-daily regimen, while others show better response with divided dosing 1
• Total daily doses above 30 mg have been safely given on a twice-daily basis to long-term patients 1

Extended-Release Glipizide Dosing

• Extended-release (XL) formulation is designed for once-daily administration 2, 3
• The maximum daily dose for extended-release formulation is 20 mg 2, 4
• The extended-release formulation provides more stable plasma drug concentrations than the immediate-release formulation 3
• Once-daily glipizide-GITS (extended-release) provides effective mean glipizide concentrations for 24 hours, even at the lowest (5 mg) dose level 5

Clinical Efficacy of Once vs. Twice Daily Dosing

• Studies have shown therapeutic equivalence between once-daily and three-times-daily dosing of glipizide, suggesting that once-daily dosing is effective for many patients 6
• Extended-release glipizide was significantly more effective than immediate-release glipizide in reducing fasting plasma glucose levels 5
• Once-daily extended-release glipizide exerted glycemic control with lower plasma glipizide concentrations and significantly lower insulin and C-peptide levels compared to immediate-release formulation 5

Special Considerations

• For patients with chronic kidney disease and eGFR > 50 mL/min/1.73 m², no dose adjustment is needed 2
• For patients with CKD and eGFR < 50 mL/min/1.73 m², initiation should be conservative (e.g., 2.5 mg once daily) and titration should be slow to avoid hypoglycemia 2
• In elderly patients, debilitated or malnourished patients, and patients with impaired renal or hepatic function, initial and maintenance dosing should be conservative to avoid hypoglycemic reactions 1
• When taking glipizide with colesevelam, glipizide should be administered at least 4 hours prior to colesevelam 1

Cost Considerations

• The median monthly cost for maximum approved daily dose of glipizide 10 mg (IR) was $75 (AWP) and $5 (NADAC) 4, 2
• The median monthly cost for glipizide 10 mg (XL) was $48 (AWP) and $15 (NADAC) 4, 2
• Monthly drug acquisition costs were lower, and glycosylated hemoglobin levels and patient compliance were improved after formulary conversion from immediate-release to extended-release formulation 3

The evidence supports that glipizide can be effectively administered once daily, particularly with the extended-release formulation, while the immediate-release formulation may require twice-daily dosing for higher doses or to achieve optimal glycemic control.