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Mast-cell stabiliser Pregnancy: SPC 4.6: Pregnancy - as with all medication, caution should be exercised especially during the first trimester; cumulative experience with sodium cromoglicate suggests that it has no adverse effects on foetal development; it should be used in pregnancy only where there is a clear need. Lactation - it is not known whether sodium cromoglicate is excreted in human breast milk but, based on its physicochemical properties, this is considered unlikely; caution should be exercised when the eye drops are administered to nursing mothers. Fertility - it is not known whether sodium cromoglicate has any effect on fertility.

Sodium cromoglicate

Brand names: Intal, Opticrom, Nalcrom

Sodium cromoglicate is a mast cell stabiliser used as a prophylactic agent in asthma and allergic conditions, including by ophthalmic and other topical routes.

Adult dose

Dose: Prevention and treatment of acute, seasonal and perennial allergic conjunctivitis (sodium cromoglicate 2% w/v eye drops): one or two drops into each eye up to four times a day, or as indicated by the doctor
Route: Ocular (topical ophthalmic eye drops)
Frequency: Up to four times a day, or as indicated by the doctor
SOURCE: UK SPC for ONE product - sodium cromoglicate 2% w/v eye drops (PL158720010, FDC International Ltd). SPC 4.2 verbatim: 'Adults and Children: One or two drops into each eye up to four times a day or as indicated by the doctor. Elderly: There is no current evidence for alteration of the dose. Route of administration: Topical ophthalmic.' The SPC prints no separate maximum dose beyond 'up to four times a day', so no maxDose is given. SCOPE - OCULAR ROUTE ONLY: 4.1 licenses this product only for the prevention and treatment of acute, seasonal and perennial allergic conjunctivitis. This page also lists inhaled and oral routes (brands Intal and Nalcrom); this SPC covers neither, so no inhaled or oral dose is given and those products' regimens and indications differ. CAUTIONS (4.4): the eye drops contain benzalkonium chloride 0.1 mg/ml (4.5 micrograms per dose) which may be deposited in soft contact lenses - do not use while wearing them; remove lenses before instillation and do not re-insert earlier than 15 minutes after use; benzalkonium chloride may cause eye irritation and symptoms of dry eyes and may affect the tear film and corneal surface - use with caution in dry eye patients and where the cornea may be compromised; patients should be monitored in case of prolonged use; ocular solutions can become contaminated if handled improperly; patients who develop an intercurrent ocular condition (e.g. trauma, ocular surgery or infection) should seek their physician's advice about continued use of the present multi-dose container. SOURCE LIMITS: text came from a PDF; no section is marked truncated; this bundle has no section 2 (composition) - the 2% w/v strength is taken from the product name.

Paediatric dose

Dose: Children: same regimen as adults - one or two drops into each eye up to four times a day, or as indicated by the doctor
Route: Ocular (topical ophthalmic eye drops)
Frequency: Up to four times a day, or as indicated by the doctor
THIS IS THE LABEL'S OWN STATEMENT, NOT A SCALED ADULT DOSE: SPC 4.2 gives one regimen headed 'Adults and Children'. The SPC prints no minimum age or age band, so this card makes no statement for neonates or infants - seek specialist/paediatric advice for them.

Dose adjustments

Renal

No renal-impairment dosing statement is printed in the retrieved sections of this SPC.

Hepatic

No hepatic-impairment dosing statement is printed in the retrieved sections of this SPC.

Dose independently re-sourced from UK Summary of Product Characteristics (SPC) via MHRA Products — clinician-reviewed. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

  • Patients with known hypersensitivity to any of the ingredients listed in section 6.1

Side effects

  • Transient stinging and burning on instillation of the drops
  • Rarely, other symptoms of local irritation
  • Benzalkonium chloride has been reported to cause eye irritation, symptoms of dry eyes and effects on the tear film and corneal surface (4.4)
  • Bacterial keratitis has been reported in association with topical ophthalmic products (4.4)

Interactions

  • None known (4.5)

Monitoring

  • Patients should be monitored in case of prolonged use (4.4)
  • Do not use while wearing soft contact lenses (benzalkonium chloride may be deposited in them): remove lenses before instillation and do not re-insert earlier than 15 minutes after use (4.4)
  • Seek the physician's advice if an intercurrent ocular condition (e.g. trauma, ocular surgery or infection) develops while using the multi-dose container (4.4)

Clinical monograph

How it works

It stabilises mast cells, inhibiting the release of histamine and other inflammatory mediators triggered by allergen exposure, thereby preventing allergic and asthmatic responses.

Prescribing in practice

  • It is purely prophylactic and ineffective for relief of an established acute asthma attack.
  • Regular continued use is required for benefit, and it should not be stopped abruptly in those whose symptoms it controls.
  • It is poorly absorbed and acts locally, so formulation must match the intended site of action.

Monitoring

Monitor symptom frequency and control to assess prophylactic benefit over time.

Counselling the patient

  • Use regularly to prevent symptoms rather than to treat an attack.
  • Continue even when well, and keep a reliever for acute symptoms if you have asthma.

Evidence & guidelines

Mast cell stabilisers have a long-established prophylactic role in allergic and asthmatic disease.

Reference: BTS/SIGN; 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).

Related

Curated clinical cross-links plus same-class fallbacks.