Synthetic ACTH (short Synacthen test)
Tetracosactide
Brand names: Synacthen, Synacthen Depot
Adult dose
Dose: Diagnostic: 250 micrograms IM/IV with cortisol at 0 and 30 min. Therapeutic depot: 1mg IM every 1-3 days (rarely used)
Route: IM/IV
Frequency: diagnostic
Clinical pearls
- Short Synacthen test for adrenal insufficiency — cortisol >430-500 nmol/L at 30 min normal
- Withhold hydrocortisone; prednisolone OK
Contraindications
- Active infection
- Hypersensitivity (esp. asthmatics)
- Cushing's syndrome
Side effects
- Hypersensitivity / anaphylaxis
- Sodium/water retention
- Hypokalaemia
- Mood changes
Interactions
- Corticosteroids (avoid morning steroid pre-test)
Monitoring
- Cortisol
- Symptoms
Reference: BNF; UK Endocrine Society; https://bnf.nice.org.uk/drugs/tetracosactide/. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Calculators
- Duke Treadmill Score · Coronary Artery Disease
- Pre-test Probability for Stable CAD (ESC 2019) · Chest Pain
- Adrenal Insufficiency Assessment · Adrenal
- Thyroid Function Test Interpretation · Thyroid Disease
- Dix-Hallpike Test Interpretation / BPPV Assessment · Vestibular
- Snellen Visual Acuity Interpretation · Ophthalmology
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