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Mast Cell Stabiliser — Allergic Rhinitis Pregnancy: Safe — preferred mast cell stabiliser in pregnancy; extensive track record of safety

Sodium Cromoglicate Nasal Spray

Brand names: Rynacrom, Nasocrom

Adult dose

Dose: 1 spray (5.2 mg) per nostril
Route: Intranasal
Frequency: Four to six times daily (preventively before allergen exposure)
Max: 6 applications per nostril per day
Mast cell stabiliser for seasonal and perennial allergic rhinitis. Must be used regularly before allergen exposure for maximum benefit — not effective for established symptoms. Less effective than intranasal corticosteroids but preferred in pregnancy and in patients wishing to avoid steroids.

Paediatric dose

Dose: 1 spray per nostril spray/kg
Route: Intranasal
Frequency: Four times daily
Max: 6 applications per nostril per day
BNFc: licensed from 5 years of age — same dose as adult. Safe for long-term use in children.

Dose adjustments

Renal

No dose adjustment required

Hepatic

No dose adjustment required

Paediatric weight-based calculator

BNFc: licensed from 5 years of age — same dose as adult. Safe for long-term use in children.

Clinical pearls

  • Preferred for prophylaxis of allergic rhinitis in pregnancy — no known fetal harm; long safety record
  • Must be started BEFORE pollen season begins — not effective once symptoms established; works by preventing mast cell degranulation
  • Inferior to intranasal corticosteroids for established AR — but patients who prefer steroid-free options or parents of young children often use this
  • Frequent dosing (4–6 times daily) is the main practical limitation — poor adherence is common
  • Also available as eye drops (Opticrom) for allergic conjunctivitis — often used in combination with nasal spray for pollinosis

Contraindications

  • Hypersensitivity to sodium cromoglicate

Side effects

  • Local nasal irritation
  • Sneezing after application
  • Epistaxis (rare)
  • Unpleasant taste (rare)

Interactions

  • No clinically significant interactions

Monitoring

  • Symptom diary
  • Nasal inspection

Reference: BNFc; BNF 90; BNFc; BSACI Rhinitis Guidelines 2017; RCOG (2022) Pharmacology in pregnancy. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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