Glyburide Dosing and Titration for Type 2 Diabetes
The recommended starting dose of glyburide for patients with type 2 diabetes is 2.5 to 5 mg daily, administered with breakfast or the first main meal, with more sensitive patients starting at 1.25 mg daily. 1
Initial Dosing Considerations
- For standard patients, initiate glyburide at 2.5 to 5 mg daily as a single dose with breakfast or the first main meal 1
- For patients who may be more sensitive to hypoglycemic medications (elderly, renal impairment, debilitated), start at a lower dose of 1.25 mg daily 1
- When transferring patients from other oral antidiabetic agents (except chlorpropamide) to glyburide, use a conservative initial daily dose of 2.5 to 5 mg 1
- For patients transferring from chlorpropamide, exercise particular caution during the first two weeks due to prolonged retention of chlorpropamide and potential overlapping drug effects that may provoke hypoglycemia 1
Titration Protocol
- Increase dosage in increments of no more than 2.5 mg at weekly intervals based on blood glucose response 1
- 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
- Daily doses exceeding 20 mg are not recommended 1
- Most patients respond adequately to once-daily dosing, but some patients (particularly those receiving more than 10 mg daily) may have a more satisfactory response with twice-daily dosing 1
Special Patient Populations
- For patients currently on insulin therapy:
- If insulin dose is less than 20 units daily, consider substituting with glyburide 2.5 to 5 mg as a single daily dose 1
- If insulin dose is between 20 and 40 units daily, patient may be placed directly on glyburide 5 mg daily as a single dose 1
- If insulin dose is more than 40 units daily, decrease insulin by 50% and start glyburide 5 mg daily 1
Monitoring and Dose Adjustments
- Monitor both urinary glucose and blood glucose periodically to determine the minimum effective dose 1
- Glycosylated hemoglobin levels may also be valuable in monitoring response to therapy 1
- Watch for primary failure (inadequate lowering of blood glucose at maximum recommended dose) or secondary failure (loss of adequate response after initial effectiveness) 1
Combination Therapy Considerations
- When coadministered with colesevelam, glyburide should be administered at least 4 hours prior to colesevelam due to reduced plasma concentration and total exposure 1
- For patients on metformin who have not responded to maximum dose monotherapy after four weeks, add glyburide gradually 1
- With concomitant glyburide and metformin therapy, adjust the dose of each drug to achieve desired blood glucose control 1
- Be aware that combination therapy with metformin may increase the risk of hypoglycemia 1
Important Cautions
- Failure to follow appropriate dosage regimen may precipitate hypoglycemia 1
- Patients who do not adhere to prescribed dietary and drug regimen are more prone to exhibit unsatisfactory response to therapy 1
- Hypoglycemia is a common adverse effect, occurring in 10-20% of patients treated for ≤1 year 2
- Avoid inappropriate high-dose glyburide therapy in patients with uncontrolled diabetes who may have developed secondary sulfonylurea failure 3
By following this structured approach to glyburide dosing and titration, clinicians can optimize glycemic control while minimizing the risk of adverse effects, particularly hypoglycemia, in patients with type 2 diabetes.