Cromolyn Sodium
Cromolyn sodium is a **mast cell stabilizing agent** used primarily in veterinary ophthalmology for the management of allergic conjunctivitis. * It lacks intrinsic vasoconstrictor, antihistaminic, cyclooxygenase (COX) inhibition, or other direct anti-inflammatory properties. * Because it prevents the release of inflammatory mediators rather than blocking their effects at the receptor level, it is most effective when used prophylactically or consistently over time. > **Clinical Pearl:** Mast cell stabilizers are generally very safe for long-term use in companion animals suffering from seasonal allergic conjunctivitis, though they may require frequent daily dosing to maintain efficacy.
Mechanism: Cromolyn sodium acts as a **mast cell stabilizer**. Upon antigen recognition, it blocks the degranulation of sensitized mast cells → prevents the release of **histamine** and **slow-reacting substance of anaphylaxis (SRS-A)** into the surrounding ocular tissues.
Dosing by species
- Relief of seasonal allergy / Allergic conjunctivitis · one drop 2-6 times daily · topical ophthalmic · q4-12h
- Relief of seasonal allergy / Allergic conjunctivitis · one drop 2-6 times daily · topical ophthalmic · q4-12h
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Routes of administration
Adverse effects
- Stinging sensation upon application (low percentage of patients)
Monitoring
- Resolution of clinical signs of allergic conjunctivitis (e.g., reduced hyperemia, chemosis, and pruritus)
Overdose
Overdose via the topical ophthalmic route is highly unlikely to cause systemic toxicity. Excess drops will simply wash out of the conjunctival sac.
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.