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Bronchodilator Pregnancy: C — safe at inhaled doses; tocolytic at high IV doses

Salbutamol (Albuterol)

Brand names: Ventolin, Salamol, Bricanyl

Adult dose

Dose: Inhaled MDI: 100–200mcg (1–2 puffs) PRN. Nebulised: 2.5–5mg. IV infusion: 3–20 mcg/min
Route: Inhaled / Nebulised / IV
Frequency: PRN (inhaler) or continuous (nebuliser in acute asthma)
Acute severe asthma: 5mg nebulised every 20–30 min or back-to-back. Life-threatening asthma: IV infusion 5–20 mcg/min. Hyperkalaemia: 10–20mg nebulised (4 vials back-to-back).

Paediatric dose

Route: Nebulised (acute asthma) / Inhaled MDI + spacer (mild–moderate)
Frequency: Every 20–30 min × 3, then reassess (acute severe)
Max: 5 mg per nebulised dose
Concentration: 5 mg/ml
Age bands
  • 1–60m: Nebulised 2.5 mg every 20–30 min in acute severe asthma
  • 60–216m: Nebulised 5 mg every 20–30 min in acute severe asthma
BNFc / BTS-SIGN paediatric asthma: nebulised 2.5 mg (child 1 month–4 years) or 5 mg (child 5–17 years) every 20–30 min in acute severe asthma; back-to-back if life-threatening. MDI + spacer (mild–moderate): up to 10 puffs (100 microgram each), one puff at a time, every 30–60 sec, repeated every 20 min. IV salbutamol (specialist, severe): 15 micrograms/kg single bolus over 5 min, then 1–5 micrograms/kg/min infusion — distinct dosing.

Clinical pearls

  • Hyperkalaemia: high-dose nebulised salbutamol (10–20mg) shifts K+ into cells — onset 30 min, reduces K+ by ~1 mmol/L. NOT a definitive treatment.
  • Spacer device = as effective as nebuliser for acute asthma in children and adults. Use MDI + spacer if nebuliser not available.
  • Inhaler technique: press inhaler, then inhale slowly over 4–5 sec, hold 10 sec — ensures lung deposition.
  • Monitor K+ in severe acute asthma — nebulised salbutamol causes hypokalaemia; exacerbated by concomitant theophylline.

Contraindications

  • Hypersensitivity to salbutamol
  • Tachyarrhythmia as sole indication (relative)
  • Threatened abortion (IV route)

Side effects

  • Tachycardia, palpitations (dose-dependent)
  • Fine tremor (common with nebulised/IV)
  • Hypokalaemia (particularly at high nebulised doses — monitor K+ in severe asthma)
  • Hyperglycaemia
  • Paradoxical bronchospasm (rare)

Interactions

  • Non-selective beta-blockers (propranolol): antagonise bronchodilation — avoid in asthma
  • Theophylline: additive hypokalaemia risk
  • Loop diuretics: additive hypokalaemia
  • Digoxin: salbutamol-induced hypokalaemia increases digoxin toxicity risk

Monitoring

  • Peak flow / FEV₁
  • HR
  • K+ in severe asthma
  • SpO₂

Reference: BNFc; BTS/SIGN Asthma 2023; NICE BNF 84. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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