Potent Systemic Corticosteroid Pregnancy: Crosses the placenta. Prescribe in pregnancy (particularly first trimester) only if benefit outweighs risk. Long-term/repeated therapy increases risk of intrauterine growth retardation; prenatal exposure carries risk of neonatal adrenal insufficiency.

Dexamethasone

Brand names: Dexsol, Martapan, Neofordex

Used in: Meningitis & Encephalitis

Dexamethasone is a potent, long-acting glucocorticoid used for cerebral oedema, croup, as an antiemetic, in some cancers and inflammatory conditions, and in severe COVID-19.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: Initial dose usually 0.5-10 mg daily, titrated to individual response and disease severity

Route: Oral (soluble tablets, taken with or after food; dissolve in at least ~50 ml water and drink immediately)

Frequency: Once daily, or divided into 3-4 doses depending on indication

Max: In more severe conditions doses above 10 mg/day may be required; very high doses up to 96 mg used in palliative treatment of neoplastic disease

Use the lowest effective dose. Indication-specific regimens (SPC, guidance only): cerebral oedema 6-16 mg (up to 24 mg)/day divided into 3-4 doses; acute asthma (adults) 16 mg/day for two days; acute skin diseases 8-40 mg/day (up to 100 mg), then down-titrate; SLE 6-16 mg/day; active rheumatoid arthritis (fast destructive) 12-16 mg/day, with extra-articular manifestations 6-12 mg/day; idiopathic thrombocytopenic purpura 40 mg for 4 days in cycles; palliative neoplastic disease 3-20 mg/day; prophylaxis/treatment of chemotherapy-induced emesis 8-20 mg before chemotherapy then 4-16 mg/day on days 2-3; prevention/treatment of postoperative vomiting single dose 8 mg before surgery; symptomatic multiple myeloma / ALL / Hodgkin's / non-Hodgkin's lymphoma (in combination) usually 40 mg or 20 mg once daily per protocol. Long-term treatment should be switched from dexamethasone to prednisone/prednisolone after initial therapy to reduce adrenal suppression; discontinue gradually after prolonged high-dose use. Elderly: plasma concentrations may be higher and excretion slower - reduce dose accordingly. Hepatic impairment (severe): dose adjustment may be necessary. Paediatric SPC doses are indication-specific per kg (e.g. acute asthma 0.6 mg/kg for 1-2 days; croup 0.15-0.6 mg/kg single dose; tuberculous meningitis IV then oral taper 0.4/0.3/0.2/0.1 mg/kg/day by week) - verify against a children's formulary.

Dose adjustments

Renal

Patients on active haemodialysis may show increased drug clearance via the dialysate and thus require an adjustment (increase) of steroid dose.

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

US labelling (FDA)

Reference — US labelling, may differ from UK

DOSAGE AND ADMINISTRATION For Oral Administration The initial dosage varies from 0.75 to 9 mg a day depending on the disease being treated. It Should Be Emphasized That Dosage Requirements Are Variable And Must Be Individualized On The Basis Of The Disease Under Treatment And The Response Of The Patient. After a favorable response is noted, the proper maintenance dosage should be determined by decreasing the initial drug dosage in small decrements at appropriate time intervals until the lowest dosage that maintains an adequate clinical response is reached. Situations which may make dosage adjustments necessary are changes in clinical status secondary to remissions or exacerbations in the …

Source: US FDA prescribing information (openFDA / DailyMed), label dated 2025-10-29. Accessed 2026-06-12. US dosing and indications can differ from UK practice — use UK sources for prescribing decisions.

Contraindications

Hypersensitivity to dexamethasone or any excipient
Systemic infection unless specific anti-infective therapy is employed
Stomach ulcer or duodenal ulcer
Vaccination with live vaccines during treatment with large therapeutic doses

Side effects

Weight gain and central obesity (Cushingoid features)
Glucose intolerance / manifestation of latent diabetes mellitus
Suppression of the hypothalamic-pituitary-adrenal axis; secondary adrenal insufficiency
Osteoporosis, muscle atrophy, skin fragility
Psychological disorders (from euphoria to psychosis, depression, insomnia)
Increased susceptibility to or exacerbation of infections; elevated intraocular pressure/glaucoma, cataract

Interactions

Live vaccines - contraindicated during high-dose therapy
Fluoroquinolones - increased risk of tendinitis and tendon rupture
Anticholinesterases - may produce severe weakness in myasthenia gravis (US label)
Oral anticoagulants (warfarin) - usually inhibits response; monitor coagulation (US label)
Potassium-depleting agents (e.g. amphotericin B, diuretics) - risk of hypokalaemia (US label)
Antidiabetics - corticosteroids may raise blood glucose; dose adjustment may be needed (US label)

Clinical monograph

How it works

A synthetic glucocorticoid with strong anti-inflammatory and immunosuppressive action and negligible mineralocorticoid (salt-retaining) effect.

Prescribing in practice

Its high glucocorticoid potency and long duration mean small milligram doses are powerful.
It causes hyperglycaemia, mood/sleep disturbance, infection risk and — with prolonged use — the full range of steroid effects; do not stop a prolonged course abruptly (adrenal suppression).
It lacks mineralocorticoid activity, so is not used where mineralocorticoid replacement is required.

Monitoring

Monitor glucose, blood pressure, mood/sleep and signs of infection; review bone and eyes with prolonged use.

Counselling the patient

It can disturb sleep and mood and raise blood sugar.
Don't stop a longer course suddenly; carry a steroid card for prolonged treatment.
Report signs of infection.

Evidence & guidelines

Improves survival in severe COVID-19 needing oxygen (RECOVERY) and is standard for cerebral oedema, croup and antiemesis.

Reference: RECOVERY Trial (NEJM 2021); NICE Bacterial Meningitis Guideline; NICE NG187; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Drugs

Betamethasone (Systemic) · Potent Systemic Corticosteroid

Pathways

📚 MRCEM Revision

Featured in these MRCEM clinical pathways

Dexamethasone is a core drug in the following exam-focused workups on our sister siteReviseMRCEM.

MRCEM Primary / Intermediate / OSCE candidates: each pathway includes exam-style questions, RCEM/NICE citations, and FAQ summaries.