Sodium cromoglicate
Sodium 5,5'-(2-hydroxypropane-1,3-diyl)bis(oxy)bis(4-oxo-4H-chromene-2-carboxylate)
Also known as: Catacrom · Intal · Nalcrom · Opticrom · Optrex allergy · Pollinase · Vividrin · Cromolyn sodium · Sodium chromoglycate · Cromoglicic acid
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
🌎 NA — North America🌍 EU — Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Allergic reactions (conjunctivitis/rhinitis) | 1-2 drops in eye or nose | Topical | q6h | — | 🌍 EU |
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Allergic reactions (conjunctivitis/rhinitis) | 1-2 drops in eye or nose | Topical | q6h | — | 🌍 EU |
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Sodium cromoglicate (also known as cromolyn sodium) is a mast cell stabilizer used primarily for the management of allergic conjunctivitis and allergic rhinitis. Its action is localized to the site of application, making it effective for topical use in the eyes and respiratory tract.
Clinical Pearl: It is most effective when used prophylactically before exposure to known allergens, as it prevents degranulation rather than reversing the effects of already released histamine.
Mechanism of action
Sodium cromoglicate works by stabilizing mast cell membranes. It inhibits the release of inflammatory mediators (such as histamine and leukotrienes) from sensitized mast cells by preventing calcium influx across the cell membrane.
Allergen exposure → Mast cell activation blocked → Prevention of degranulation → Decreased allergic inflammation.
Safety & warnings
Contraindications
- Known hypersensitivity to cromoglicate
Adverse effects
- Local irritation
- Transient stinging or burning upon application
Precautions
Normal precautions should be observed. May cause transient stinging upon administration. Ensure the dropper tip does not touch the eye or surrounding structures to prevent contamination.
Monitoring
- Resolution of allergic clinical signs (e.g., reduced ocular discharge, conjunctival hyperemia, or sneezing)
Pharmacokinetics
Absorption
Poorly absorbed systemically from the GI tract or mucous membranes. Action is primarily localized to the site of application.
Distribution
Minimal systemic distribution due to poor absorption.
Metabolism
Not metabolized.
Elimination
Excreted unchanged in bile and urine (if systemically absorbed) or feces (if ingested).
Overdose
Due to poor systemic absorption, systemic toxicity from topical or oral overdose is highly unlikely. Overdose may result in increased local irritation.
Available products
Formulations
- 2% ocular drops
- 2% nasal spray
- 4% nasal spray
- 100 mg tablet
Human-labeled
- Catacrom
- Intal
- Nalcrom
- Opticrom
- Optrex allergy
- Pollinase
- Vividrin
Regulatory status
Human registered products used off-label.
Listed as P (Pharmacy) and POM (Prescription Only Medicine) depending on formulation.
No regulatory data for: 🇺🇸 US · 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store at room temperature, away from direct sunlight and moisture. Keep containers tightly closed.
Client information
Sodium cromoglicate is used to prevent and treat allergic reactions in the eyes or nose.
- Administration: Apply the drops exactly as prescribed. Do not touch the dropper tip to the eye or any surface to prevent contamination.
- Expectations: It may take a few days of consistent use to see the full effect. It works best when given regularly to prevent allergies.
- Side Effects: Your pet may experience mild, temporary stinging or irritation right after the drops are applied. If the eye becomes increasingly red, cloudy, or painful, contact your veterinarian.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.