II. Indications: Type II Diabetes Mellitus (early, phase 1-2)
- Better effect in lean patients
- Consider when Hemoglobin A1C <9%
- Second-line to Metformin in most patients
- Consider as first-line in specific cohorts
III. Contraindications
- Sulfa Allergy (applies to Sulfonylureas)
- Renal and liver dysfunction
- Use caution with Sulfonylureas (especially Glyburide)
- Repaglinide or Nateglinide may be preferred here
- Avoid most Sulfonylureas when GFR <60 ml/min (higher risk of Hypoglycemia)
- Glipizide Half-Life is not impacted by lower GFR and is safer to use in low GFR
- Avoid Glyburide in cardiovascular disease (and in general due to Hypoglycemia risk)
- Glimepiride and Glipizide do not appear to increase risk
IV. Mechanism
-
Sulfonylureas trigger Insulin release from pancreatic beta cells
- Sulfonylureas stimulate Potassium channel closure on pancreatic beta cell surface
- Secretagogues do NOT burn out the beta cells sooner
- Sulfonylureas may also increase tissue Insulin sensitivity
V. Medications: Glipizide
- Glipizide (Glucotrol) tablets 5 mg, 10 mg
- Glipizide Extended Release (Glucotrol XL) tablets 2.5 mg, 5 mg, 10 mg
- Advantages: Least expensive Sulfonylurea, long acting Sulfonylureas are preferred
- Disadvantages: Extended release may increase Hypoglycemia risk when compared with immediate release
VI. Dosing
-
General
- Increase dose every 1-2 weeks until adequate response
- No response to Sulfonylureas in 25-30% of Type II Diabetics
- Long acting Sulfonylureas are preferred, but Glipizide XL may be at higher risk of Hypoglycemia
- Glipizide (Glucotrol)
- Start: 5 mg orally daily
- Start at 2.5 mg orally daily in elderly or liver disease
- Titrate in 2.5 to 5 mg increments
- Usual: 10-20 mg orally daily
- Daily doses >15 mg should be divided twice daily
- Maximum: 20 mg orally twice daily (40 mg/day)
- Start: 5 mg orally daily
- Glipizide Extended Release (Glucotrol XL)
- Start: 5 mg orally daily taken 30 minutes before breakfast
- Usual: 5 to 10 mg orally daily
- Maximum: 20 mg orally daily
- Doses above 10 mg daily ER, are unlikely to offer benefit (divide twice daily if used)
VII. Adverse Effects
- See Sulfonylurea Poisoning
- Hemolytic Anemia in G6PD Deficiency Risk
- Weight gain
-
Hypoglycemia
- See Sulfonylurea Drug Interactions Causing Hypoglycemia
- Higher risk of severe Hypoglycemia with Glyburide than other Sulfonylureas
- Hypoglycemia risk increases with lower GFR
- Glipizide may be preferred instead due to increased risks of Hypoglycemia associated with Glyburide, Glimepiride
- Other agents are generic (no cost advantage to Glyburide)
- Cardiovascular Disease
- Early studies had suggested possible increased Cardiovascular Risk
- Does not appear to be at increased risk with Sulfonylureas overall
- However, still avoid Glyburide in cardiovascular disease (and in general due to Hypoglycemia risk)
- Glimepiride and Glipizide appear to be neutral in their Cardiovascular Risk effects
- Contrast with GLP-1 Agonists and SGLT2 Inhibitors which reduce Cardiovascular Risk
- (2019) presc lett 26(12): 71
VIII. Safety
- Unknown safety in Lactation
- Unknown safety in pregnancy
- Discontinue at least 2 weeks before delivery (risk of Neonatal Hypoglycemia)
IX. Drug Interactions
- See Sulfonylurea Drug Interactions Causing Hypoglycemia
- Never combine Insulin Secretagogues (Sulfonylureas or Meglitinides)
- They all have same site of activity
- If one does not work, then all will not work
X. Efficacy
-
Sulfonylurea effects as a class
- Lower Hemoglobin A1C 0.8 to 1.5%
- Do not affect all-cause mortality
XI. Resources
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Related Studies
glipizide (on 10/19/2022 at Medicaid.Gov Survey of pharmacy drug pricing) | ||
GLIPIZIDE 10 MG TABLET | Generic | $0.05 each |
GLIPIZIDE 5 MG TABLET | Generic | $0.03 each |
GLIPIZIDE ER 10 MG TABLET | Generic | $0.17 each |
GLIPIZIDE ER 2.5 MG TABLET | Generic | $0.14 each |
GLIPIZIDE ER 5 MG TABLET | Generic | $0.11 each |
GLIPIZIDE XL 10 MG TABLET | Generic | $0.17 each |
GLIPIZIDE XL 2.5 MG TABLET | Generic | $0.14 each |
GLIPIZIDE XL 5 MG TABLET | Generic | $0.11 each |
GLIPIZIDE-METFORMIN 2.5-250 MG | Generic | $0.29 each |
GLIPIZIDE-METFORMIN 2.5-500 MG | Generic | $0.26 each |
GLIPIZIDE-METFORMIN 5-500 MG | Generic | $0.27 each |