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: Dexamethasone, Martapan

Dexamethasone is a potent long-acting glucocorticoid used in neurology principally to reduce vasogenic cerebral oedema associated with brain tumours and certain intracranial pathology, and as adjunctive therapy in bacterial meningitis.

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: Cerebral oedema: 6-16 mg (up to 24 mg) per day orally, divided into 3-4 doses (initial dose and duration depend on cause and severity)

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

Frequency: Divided into 3-4 doses per day for cerebral oedema; overall initial range 0.5-10 mg daily titrated to response

Max: Up to 24 mg/day for cerebral oedema; in more severe conditions doses above 10 mg/day may be required (very high doses up to 96 mg used in palliative neoplastic disease)

Neurology context - leading regimen shown is cerebral oedema. Tuberculous meningitis (SPC): grade II/III disease - IV for 4 weeks (0.4 mg/kg/day week 1, 0.3 week 2, 0.2 week 3, 0.1 week 4) then oral 4 weeks starting 4 mg/day decreasing 1 mg each week; grade I disease - IV 2 weeks (0.3 mg/kg/day week 1, 0.2 week 2) then oral 4 weeks (0.1 mg/kg/day week 3, then 3 mg/day decreasing 1 mg each week). Other SPC indications: acute asthma (adults) 16 mg/day for 2 days; palliative neoplastic disease 3-20 mg/day; SLE 6-16 mg/day. Use the lowest effective dose. Long-term treatment should be switched to prednisone/prednisolone after initial therapy; discontinue gradually after prolonged high-dose use. Note SPC caution: increased intracranial pressure with papilloedema (pseudotumor cerebri) usually follows discontinuation, and pre-existing myasthenia gravis may deteriorate at start of treatment. Elderly: reduce dose. Severe hepatic impairment: dose adjustment may be necessary. Per-kg paediatric TB-meningitis doses above - 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.

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
Increased intracranial pressure with papilloedema in children (pseudotumor cerebri), usually following discontinuation; headache, vertigo
Psychological disorders (from euphoria to psychosis, depression, insomnia)
Osteoporosis, muscle atrophy, skin fragility; increased susceptibility to infection

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

It binds glucocorticoid receptors to exert powerful anti-inflammatory and immunosuppressive effects and stabilises the blood-brain barrier, reducing peritumoural oedema; it has negligible mineralocorticoid activity.

Prescribing in practice

Do not stop abruptly after more than a short course, as adrenal suppression risks an adrenal crisis; dosing should be tapered and a steroid emergency card issued.
Co-prescribe gastroprotection where indicated and monitor for hyperglycaemia, neuropsychiatric effects and increased infection risk during treatment.
Give doses earlier in the day to limit insomnia and counsel on raised blood glucose, mood changes and proximal myopathy with prolonged use.

Monitoring

Monitor blood glucose, blood pressure, weight, mood and signs of infection during treatment, with bone and gastrointestinal protection considered for prolonged courses.

Counselling the patient

Never stop the steroid suddenly and carry a steroid alert card.
Report mood changes, marked thirst, infection symptoms or indigestion.
Take in the morning to reduce difficulty sleeping.

Evidence & guidelines

Adjunctive dexamethasone improves outcomes in bacterial meningitis in appropriate patients, and it is a long-standing standard treatment for symptomatic cerebral oedema from intracranial tumours.

Reference: NICE NG240 Bacterial Meningitis; 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.

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