First-generation sulfonylurea (short-acting)
Tolbutamide
Adult dose
Dose: 500mg–2g PO/day in 1-2 divided doses
Route: PO
Frequency: OD-BD
Dose adjustments
Renal
Use cautiously
Clinical pearls
- Largely superseded by gliclazide; useful in elderly/renal impairment due to short half-life
- Avoid driving until stable
Contraindications
- Type 1 DM
- DKA
- Severe hepatic/renal impairment
- Pregnancy/breastfeeding
- Sulfonylurea/sulfonamide hypersensitivity
- Acute porphyria
Side effects
- Hypoglycaemia
- Weight gain
- Hyponatraemia
- Cytopenias
- Cholestatic jaundice
Interactions
- β-blockers (mask hypos)
- NSAIDs
- Warfarin
- Alcohol
- Sulfonamides
Monitoring
- HbA1c
- Glucose
- FBC
Reference: BNF; NICE NG28; https://bnf.nice.org.uk/drugs/tolbutamide/. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Calculators
- First Unprovoked Seizure — Recurrence Risk · Epilepsy
- Epilepsy Risk after First Seizure (MESS Score) · Epilepsy
- Cervical Cerclage Criteria (Short Cervix / Preterm Risk) · Preterm Labour
- Brief Pain Inventory — Short Form (BPI-SF) · Pain
- Montreal Cognitive — Short Screening for Substance Misuse · Substance Misuse Screening
- Short Michigan Alcoholism Screening Test (SMAST) · Alcohol Use
Pathways
- Diabetic Ketoacidosis (DKA) · JBDS 2013 / Joint British Diabetes Societies; NICE NG17
- Adult Hypoglycaemia (Treated Diabetes) · JBDS-IP (2023): Hospital Management of Hypoglycaemia
- Adrenal Crisis · Society for Endocrinology Emergency Guidance (2024)
- Type 2 Diabetes Management · NICE NG28 2022
- Hyperthyroidism Management · BTA / ETA 2018
- Adrenal Insufficiency · Society of Endocrinology / ESE 2016