| Acarbose (Precose) | Maximum: 50 to 100 mg three times daily | Lack of data in patients with a serum creatinine level higher than 2 mg per dL (180 μmol per L); therefore, acarbose should be avoided in these patients18 |
| Chlorpropamide (Diabinese) | 100 to 500 mg daily | Avoid in patients with a glomerular filtration rate less than 50 mL per minute because of the increased risk of hypoglycemia19 |
| Glipizide (Glucotrol) | 5 mg daily | Dosage adjustment not necessary in patients with renal impairment |
| Glyburide (Micronase) | 2.5 to 5 mg daily | 50 percent of the active metabolite is excreted via the kidney, creating a potential for severe hypoglycemia; not recommended when creatinine clearance is less than 50 mL per minute (0.83 mL per second)18 |
| Metformin (Glucophage) | 500 mg twice daily | Avoid if serum creatinine level is higher than 1.5 mg per dL (130 μmol per L) in men or higher than 1.4 mg per dL (120 μmol per L) in women, and in patients older than 80 |
| Metformin (extended release) | 500 mg daily | years or with chronic heart failure; fixed-dose combination with metformin should be used carefully in renal impairment; metformin should be temporarily discontinued for 24 to 48 hours before use of iodinated contrast agents, not restarted for 48 hours afterward, and then restarted only when renal function has normalized19 |