Cetirizine ophthalmic solution 0.24% appears to safely and effectively treat symptoms associated with allergic conjunctivitis, according to a two phase 3 double-masked, randomized, vehicle-controlled parallel group trials involving ~200 individuals.
Both studies, which used the conjunctival allergen challenge (CAC) model, were run over 5 weeks. Participants were screened for an allergen response at the first two visits, and then randomized at the third visit. Investigators assessed ocular itching, conjunctival redness, and other factors at various time points after treatment. Among the results:
Meier E, Torkildsen G, Gomes P, Jasek M. Phase III trials examining the efficacy of cetirizine ophthalmic solution 0.24% compared to vehicle for the treatment of allergic conjunctivitis in the conjunctival allergen challenge model. Clin Ophthalmol. 2018 Dec 13;12:2617-2628. doi: 10.2147/OPTH.S185835.