Pediatric Dexamethasone
Calculator

Dexamethasone is a potent fluorinated corticosteroid with 6–7 times the anti-inflammatory potency of prednisolone and 30 times that of hydrocortisone. Its unique pharmacological properties — minimal mineralocorticoid activity, penetration of the blood-brain barrier, and long duration of action — make it indispensable in specific pediatric clinical scenarios.

In pediatric emergency and critical care settings, dexamethasone is the corticosteroid of choice for croup (viral laryngotracheobronchitis), acute asthma exacerbations when oral agents are not tolerated, cerebral oedema, and antiemetic prophylaxis. Each indication carries a distinct dose and frequency.

Because of its high potency, even modest errors in dexamethasone dosing carry a greater risk of clinically significant adverse effects than equivalent errors with less potent corticosteroids. Accurate, verified weight-based calculation is essential for every dose.

Croup (single oral or IM dose): 0.6 mg/kg (maximum 16 mg) as a single dose — the most evidence-based indication for paediatric dexamethasone. A single well-timed dose produces a dramatic and sustained reduction in croup symptoms and is more effective and longer-lasting than nebulised budesonide. Repeat dosing is rarely required.

Acute asthma exacerbation: 0.3 mg/kg (maximum 10 mg) once daily. A 1–2 day course with dexamethasone has been shown to be non-inferior to a 3–5 day prednisolone course with significantly better adherence and tolerability. This regimen is gaining rapid adoption in paediatric emergency departments.

Cerebral oedema / raised intracranial pressure (IV/IM): 0.25 mg/kg (maximum 10 mg) every 6–12 hours, titrated to clinical response. This indication requires inpatient specialist management and close neurological monitoring. The calculator flags this indication for specialist review.

Antiemetic adjunct: 0.15 mg/kg (maximum 8 mg) as a single dose. Used as an adjunct in procedural sedation and chemotherapy antiemesis protocols. Dexamethasone's prolonged duration of action makes a single dose effective for up to 24 hours.

Enter the child's weight (in kg, g, or lb), age, and select the clinical indication from the preset list. Each indication loads the appropriate mg/kg rate, maximum single dose, and recommended frequency. The calculator applies the rate, caps at the maximum, converts to the volume of the selected formulation, and applies mL rounding.

A custom mode allows clinicians to override all preset values and enter a specific mg/kg figure — useful for off-label indications or specialist protocols. A validation range flags entries outside 0.05–1.0 mg/kg, where dexamethasone is not conventionally dosed in children.

Formulations supported include: Oral solution 0.5 mg/5 mL, Oral solution 1 mg/mL, Tablet 0.5 mg, Tablet 1 mg, and Injection 4 mg/mL. The injection formulation result is expressed in mL — clinicians should confirm that the injection product is approved for the intended route (IV, IM, or oral off-label).

Inline warnings are displayed for: very young age (under 6 months — specialist assessment advised), cerebral oedema indication (requires specialist input), doses exceeding the standard maximum, and high-frequency regimens (q6h — monitoring and taper plan required).

Daily dose totals are calculated for multi-dose regimens, enabling verification that cumulative daily exposure remains within a clinically appropriate range.

The same weight-based formula applies across all pediatric corticosteroid calculations, with indication-specific mg/kg rates and maximum dose caps:

Dexamethasone is preferred over prednisolone in paediatric croup and increasingly in asthma exacerbations due to its single-dose or 1–2 day convenience, eliminating the adherence challenges of 3–5 day prednisolone courses. A single dose of 0.6 mg/kg dexamethasone is equivalent to a full 3-day course of 1 mg/kg/day prednisolone for croup.

Prednisolone remains preferred for nephrotic syndrome, prolonged autoimmune courses, and conditions where titrated daily dosing is required — partly because of its shorter half-life, which makes gradual tapering more manageable.

The potency ratio (1 mg dexamethasone ≈ 6–7 mg prednisolone) must be remembered when discussing doses with caregivers or when switching between the two agents — a dose of 0.6 mg/kg dexamethasone for croup would be approximately 4 mg/kg in prednisolone-equivalent terms.