Nedocromil sodium in two models of conjunctival immediate hypersensitivity

The effects of intravenous administration of nedocromil sodium were investi gated in active and passive models of conjunctival immediate hypersensitivi ty in rats. In the active sensitization model, animals were immunized with ovalbumin 21 days prior to ocular instillation of a solution containing ova lbumin. Nedocromil sodium administered prior to antigen challenge significa ntly inhibited emergence of conjunctival edema and erythema (P<.05) and red uced mast cell degranulation (P<.02). In the passive-sensitization model, t he conjunctiva in one eye was injected with ovalbumin antiserum 48 hours pr ior to intravenous administration of ovalbumin. Nedocromil sodium administe red prior to antigen challenge significantly and dose-dependently reduced a ppearance of the signs of conjunctivitis (P<.01) as well as vascular leakag e (P<.05). These data indicate that intravenous nedocromil sodium is effect ive in animal models of allergic conjunctivitis and may have potential for wider therapeutic application. These data are also consistent with results of clinical studies in which nedocromil sodium relieved symptoms of allergi c conjunctivitis and further support a role for nedocromil sodium in the pr evention of allergic conjunctivitis.