What is the typical dosing frequency of glyburide (a sulfonylurea oral hypoglycemic medication)?

Glyburide Dosing Frequency

Glyburide can be taken either once or twice daily, depending on the total daily dose and patient-specific factors, with doses up to 10 mg typically given once daily and higher doses (above 10 mg) usually split into twice-daily administration. 1

Standard Dosing Patterns

The FDA-approved dosing for glyburide demonstrates flexibility in administration frequency:

• Once-daily dosing: The usual starting dose is 2.5 to 5 mg daily, administered with breakfast or the first main meal 1
• Twice-daily dosing: When doses exceed 10 mg daily, the medication is typically divided into two doses 2, 1
• Maintenance dosing: The usual maintenance dose ranges from 1.25 to 20 mg daily, which may be given as a single dose or in divided doses 1

Specific Dosing Examples from Guidelines

Clinical practice guidelines provide concrete dosing schedules:

• 2.5 mg twice daily is a recognized dosing regimen 2
• 5 mg once daily or 5 mg twice daily are both standard options 2
• 10 mg twice daily represents the maximum dose for patients under 65 years of age 3
• 10 mg once daily is the recommended maximum for patients 65 years or older 3

Special Considerations During Fasting

During periods of fasting (such as Ramadan), glyburide should be taken at the time of the main meal, reflecting its classification as an older-generation sulfonylurea with moderate to high hypoglycemia risk 2

Important Clinical Caveats

Glyburide carries a higher risk of hypoglycemia compared to newer sulfonylureas, which is why the American Diabetes Association guidelines classify it as having "moderate to high" hypoglycemia risk 2. This risk profile makes the dosing frequency decision clinically important:

• Patients more sensitive to hypoglycemic drugs should start at 1.25 mg daily 1
• Elderly or debilitated patients should be started on lower dosages initially 4
• The medication should be avoided in patients with eGFR <50 mL/min/1.73 m² 5

Practical Algorithm for Dosing Frequency

For doses ≤10 mg daily: Administer as a single morning dose with breakfast 1

For doses >10 mg daily: Split into twice-daily dosing (e.g., 5 mg twice daily, 10 mg twice daily) 2, 1

For elderly patients (≥65 years): Maximum 10 mg once daily regardless of glycemic control 3