Cromoglicic acid
Mast cell stabilisers
Mast cell stabilisers
A mast cell stabiliser that prevents asthma, allergic rhinitis and allergic eye symptoms; it is very safe but does not stop an attack.
Also called: Sodium cromoglicate, Cromolyn sodium
Quick facts
- Group
- Mast cell stabilisers
- Target
- Mast cell mediator release
- Used for
- Prevention of asthma symptoms · Allergic rhinitis
- Key effects
- Unpleasant taste · Nasal stinging or sneezing
- Monitor
- Symptom diary and rescue inhaler use
- ATC
- R03BC01
No doses: the clinician sets them by the current guideline.
Mechanism of action
Cromoglicic acid (used as sodium cromoglicate) inhibits degranulation of sensitised mast cells after antigen exposure, so less histamine and other mediators are released. It appears to block calcium entry into the cell indirectly. It blunts both the early and late bronchoconstrictor responses to inhaled allergen and also reduces bronchospasm from exercise, cold air and pollutants. It has no bronchodilator or antihistamine action of its own and is barely absorbed into the body.
- Cromoglicate reaches mast cells in the airway, nose or eye
- It indirectly blocks calcium entry into the mast cell
- The mast cell does not degranulate when allergen arrives
- Less histamine and leukotriene: fewer symptoms
Indications
- Prevention of asthma symptoms (nebulised) Asthma →
- Prevention of bronchospasm from exercise, cold air or allergen
- Allergic rhinitis (nasal spray) Allergic rhinitis →
- Allergic conjunctivitis (eye drops) Conjunctivitis →
Adverse effects
Common
- Cough and throat irritation after inhalation
- Unpleasant taste
- Nasal stinging or sneezing (spray); eye stinging (drops)
Contraindications
- Hypersensitivity to cromoglicate
- No role in treating an acute asthma attack or status asthmaticus
Key interactions
- Inhaled corticosteroids and bronchodilators
- No significant interactions; it is added to them, not used instead of the rescue inhaler
What is monitored
- Symptom diary and rescue inhaler use
- Cough or wheeze right after inhalation
Administration and safety
- Nebuliser solution for inhalation; nasal spray and eye drops for local allergy; an oral solution for mastocytosis
- Given shortly before exercise or exposure when used to prevent bronchospasm
- Used regularly every day for prevention, even when well
Pregnancy and breastfeeding
Very little reaches the bloodstream and long experience has not shown harm; it is considered one of the safer options in pregnancy, decided with the clinician.
Nursing care
- Explain that it prevents but does not relieve symptoms; the rescue inhaler stays available
- Teach nebuliser use and cleaning
- Tell the patient that benefit may take weeks to appear
Pharmacokinetics
- Absorption
- Very little is absorbed from the lung, nose, eye or gut; it acts locally
- Elimination
- The small absorbed fraction leaves unchanged in urine and bile
- Onset and duration
- Protection when given shortly before a trigger; full benefit after weeks of regular use
Test yourself
Think of the answer, then tap the question to see it.
What is the mechanism of cromoglicic acid?
It stabilises mast cells and prevents their degranulation after allergen exposure.
Does cromoglicic acid help in status asthmaticus?
No; it has no bronchodilator action and no role in acute attacks.
Why are systemic side effects of cromoglicate rare?
Very little is absorbed; it acts locally.
Connections
← Back to the class: Mast cell stabilisers
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: DailyMed - CROMOLYN SODIUM INHALATION SOLUTION solution (DailyMed (U.S. National Library of Medicine), 2025); Cromolyn Oral Inhalation: MedlinePlus Drug Information (MedlinePlus (U.S. National Library of Medicine), 2016); ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026).
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Representative model, for educational purposes only.