DIABINESE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for DIABINESE (DIABINESE).
Sulfonylurea that stimulates insulin release from pancreatic beta cells by blocking ATP-sensitive potassium channels, leading to cell depolarization and calcium influx. Also may increase peripheral insulin sensitivity.
| Metabolism | Extensively metabolized in the liver via CYP2C9 to active and inactive metabolites; exhibits prolonged half-life (36 hours) due to enterohepatic circulation. |
| Excretion | Primarily renal (up to 80% unchanged); minor fecal (biliary) excretion (<10%). |
| Half-life | Terminal elimination half-life 25–36 hours; in renal impairment, half-life prolonged significantly. |
| Protein binding | 90–95% bound to serum albumin. |
| Volume of Distribution | 0.1–0.2 L/kg, indicating limited extravascular distribution. |
| Bioavailability | Oral: ~100% (well absorbed). |
| Onset of Action | Oral: hypoglycemic effect begins within 1 hour; peak effect at 4–6 hours. |
| Duration of Action | Duration up to 60 hours; protracted action due to long half-life increases risk of hypoglycemia. |
| Action Class | Sulfonylureas (Insulin Secretogogues) |
Initial: 250 mg orally once daily, increase by 125-250 mg every 1-2 weeks as needed. Maintenance: 100-500 mg once daily. Maximum: 750 mg daily.
| Dosage form | TABLET |
| Renal impairment | GFR 30-50 mL/min: reduce dose by 50%. GFR <30 mL/min: contraindicated. |
| Liver impairment | Child-Pugh Class A: no adjustment. Child-Pugh Class B: reduce dose by 50%. Child-Pugh Class C: contraindicated. |
| Pediatric use | Not recommended for pediatric use due to lack of safety and efficacy data. |
| Geriatric use | Start with 100 mg orally once daily; avoid long-acting sulfonylureas due to increased hypoglycemia risk. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for DIABINESE (DIABINESE).
| Breastfeeding | Chlorpropamide excreted in breast milk; M/P ratio approximately 0.3. Potential for neonatal hypoglycemia; contraindicated in nursing mothers. |
| Teratogenic Risk | Pregnancy category C. First trimester: No well-controlled studies; potential risk of hypoglycemia. Second and third trimesters: May cause neonatal hypoglycemia; avoid use near term. Known to cross placenta. |
| Fetal Monitoring |
■ FDA Black Box Warning
Increased risk of cardiovascular mortality compared to diet alone or diet plus insulin based on the University Group Diabetes Program (UGDP) study. This warning has been controversial and is not uniformly applied to all sulfonylureas.
| Serious Effects |
["Type 1 diabetes mellitus","Diabetic ketoacidosis","Known hypersensitivity to chlorpropamide or other sulfonylureas","Renal or hepatic impairment (relative, but increased risk of prolonged hypoglycemia)"]
| Precautions | ["Hypoglycemia, especially in elderly, debilitated, or malnourished patients, or those with renal or hepatic impairment","Hemolytic anemia in patients with G6PD deficiency","Disulfiram-like reactions with alcohol","May cause photosensitivity"] |
| Food/Dietary | Alcohol: disulfiram-like reaction and increased hypoglycemia risk. High-fiber foods may decrease absorption; take with first main meal. Consistent carbohydrate intake is essential to avoid hypoglycemia. Avoid large amounts of caffeine as it may increase blood sugar. Grapefruit juice may alter metabolism; limit intake. |
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| Monitor maternal blood glucose, HbA1c, and signs of hypoglycemia. Fetal monitoring includes ultrasound for growth and amniotic fluid index; assess for macrosomia and polyhydramnios. |
| Fertility Effects | No known direct effects on fertility. Improved glycemic control may enhance fertility in diabetic women. |
| Clinical Pearls | Diabinese (chlorpropamide) is a first-generation sulfonylurea with a prolonged half-life (36 hours), increasing risk of prolonged hypoglycemia, especially in elderly or renally impaired patients. Avoid use in patients with G6PD deficiency due to risk of hemolytic anemia. Discontinue 48-72 hours before elective surgery or iodinated contrast to reduce risk of hypoglycemia and lactic acidosis. Potentiates antidiuretic hormone (ADH), so monitor for hyponatremia and fluid retention. Not recommended in hepatic impairment due to altered metabolism. |
| Patient Advice | Take exactly as prescribed, usually once daily with breakfast to reduce GI upset. · Do not skip meals as this can lead to dangerously low blood sugar (hypoglycemia). · Recognize symptoms of hypoglycemia: shakiness, sweating, fast heartbeat, confusion, blurred vision; treat with fast-acting sugar (e.g., glucose tablets, fruit juice). · Avoid alcohol as it can cause disulfiram-like reaction (flushing, nausea, headache) and increase hypoglycemia risk. · Report prolonged illness, fever, or stress that may affect blood sugar control. · Sun exposure can cause photosensitivity; use sunscreen and protective clothing. · Inform all healthcare providers that you are taking Diabinese, especially before surgeries or diagnostic procedures. · Do not take other medications, including over-the-counter drugs, without consulting your doctor. |