A comparison of the clinical efficacy of pheniramine maleate/naphazoline hydrochloride ophthalmic solution and olopatadine hydrochloride ophthalmic solution in the conjunctival allergen challenge model.
Author(s): Greiner JV, Udell IJ
Affiliation(s): Schepens Eye Research Institute, Harvard Medical School, Boston, Massachusetts 02114, USA.
Publication date & source: 2005-05, Clin Ther., 27(5):568-77.
Publication type: Clinical Trial; Randomized Controlled Trial
BACKGROUND: The signs and symptoms of allergic conjunctivitis include ocular redness and itching. Two treatment options currently indicated for acute ocular allergic reaction are pheniramine maleate 0.3%/naphazoline hydrochloride 0.025% ophthalmic solution, an over-the-counter antihistamine/vasoconstrictor combination; and olopatadine hydrochloride 0.1% ophthalmic solution, a prescription antihistamine/mast cell stabilizer. OBJECTIVE: This study was designed to compare, at onset of action, the relative effectiveness of pheniramine/naphazoline and olopatadine, when administered before conjunctival allergen challenge (CAC), using the ocular allergy index (OAI) as the primary end point. METHODS: This was a prospective, randomized, double-masked, contralateral, active- and placebo-controlled, single-center study of the CAC model. The first 2 study visits established and confirmed the subjects' ocular allergic reaction (no medication administered). At visit 3, the subjects were randomly assigned to 1 of 3 contralateral (right eye vs left eye) treatment combinations: pheniramine/naphazoline + olopatadine, pheniramine/naphazoline + placebo, or olopatadine + placebo. Medication was given 10 minutes before CAC. The subjects' erythema in the ciliary, conjunctival, and episcleral vessel beds; eyelid swelling; chemosis; and itching were evaluated at 7, 12, and 20 minutes after CAC. The OAI was calculated as a composite score of 6 signs and symptoms of allergic conjunctivitis to assess global severity. Between-treatment differences in OAI scores were used to evaluate efficacy. Subjects were asked their eye drop preference at the conclusion of visit 3. RESULTS: Subjects (n = 83) ranged in age from 20 to 70 years (mean, 42.5 years), 61.4% (n = 51) were female, and 94.0% (n = 78) were white. Both pheniramine/naphazoline and olopatadine were associated with significantly lower OAI scores than placebo at all 3 time points (all, P < 0.001). OAI scores were significantly lower with pheniramine/naphazoline than with olopatadine at 12 and 20 minutes (P = 0.005 and P = 0.001, respectively). CONCLUSION: In this patient sample, studied in a CAC model of onset of action, prophylactic pheniramine/naphazoline was more effective than olopatadine and placebo in alleviating the signs and symptoms of the acute ocular allergic reaction, as measured by the OAI.