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VARIOUS › DIAGNOSTIC AGENTS › OTHER DIAGNOSTIC AGENTS › Tests for diabetes
tolbutamide
V04CA01
Adult Dosing
- Type 2 Diabetes Mellitus: Initial 1000 mg to 2000 mg daily administered as a single dose or in divided doses
- Maintenance: 250 mg to 3000 mg daily, maximum recommended daily dose is 3000 mg
- Diagnostic use (hypoglycemia evaluation): 1 g IV given over 2 to 3 minutes
Pediatric Dosing
- Safety and efficacy in pediatric patients have not been established
Indications
- Adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus
- Diagnostic agent for the diagnosis of functioning islet cell adenomas (off-label/historical IV use)
Mechanism of Action
- First-generation sulfonylurea that stimulates insulin release from pancreatic beta cells by closing ATP-sensitive potassium channels
- Reduces hepatic glucose output and may increase peripheral insulin sensitivity with chronic use
Contraindications
- Known hypersensitivity to tolbutamide or other sulfonylureas
- Type 1 diabetes mellitus
- Diabetic ketoacidosis, with or without coma
- Severe renal, hepatic, or thyroid dysfunction
Adverse Reactions
- Hypoglycemia (potentially severe and prolonged)
- Nausea, heartburn, gastrointestinal distress
- Dizziness, headache, drowsiness
- Dermatologic reactions (pruritus, erythema, urticaria, photosensitivity)
- Hematologic abnormalities (leukopenia, agranulocytosis, thrombocytopenia, hemolytic anemia)
- Elevated liver enzymes, jaundice
Drug Interactions
- Potentiation of hypoglycemic effect with NSAIDs, salicylates, sulfonamides, azole antifungals, and coumarin anticoagulants
- Attenuation of hypoglycemic effect with thiazide diuretics, corticosteroids, oral contraceptives, and sympathomimetics
- Enhanced risk of severe hypoglycemia with alcohol, potentially inducing a disulfiram-like reaction
- Increased risk of hypoglycemia when combined with beta-blockers, which may also mask hypoglycemic symptoms
Curated Content: Needs Vetting Before Put to Clinical Use