Clinical efficacy of olopatadine vs epinastine ophthalmic solution in the conjunctival allergen challenge model.
BACKGROUND
Olopatadine hydrochloride 0.1% ophthalmic solution (Patanol) and epinastine hydrochloride 0.05% ophthalmic solution (Elestat) are two topical antiallergic agents. Olopatadine is indicated for the treatment of the signs and symptoms of allergic conjunctivitis that include itching, redness, tearing, lid swelling, and chemosis. Epinastine is indicated for the prevention of itching associated with allergic conjunctivitis.


OBJECTIVE
This study compared the clinical efficacy of olopatadine and epinastine in the prevention of itching and conjunctival redness in the conjunctival allergen challenge (CAC) model.


METHODS
This was a prospective, randomized, double-masked, contralaterally-controlled, single center allergen challenge study. Ninety-six subjects with a history of allergic conjunctivitis were screened, and the 66 who responded to conjunctival allergen challenge at visits 1 and 2 were randomized into 1 of 3 treatment groups at visit 3 to receive one drop of study medication in each eye: (1) olopatadine in one eye and epinastine in the fellow eye, (2) olopatadine in one eye and placebo in the fellow eye, and (3) epinastine in one eye and placebo in the fellow eye. Five minutes after study drop instillation, subjects were bilaterally challenged with the allergen concentration that had elicited a positive conjunctival allergic response at Visits 1 and 2. Subjective itching assessments were given at 3 min, 5 min, and 7 min post challenge. Objective redness and chemosis assessments were made at 10 min, 15 min, and 20 min post challenge. Paired sample two-tailed t-tests were performed on the mean scores at each time point to assess statistical significance in the differences between treatments. MAIN OUTCOME MEASURES;


RESULTS
Fifty-three subjects were randomized into the olopatadine/epinastine treatment group, the primary analysis group. Olopatadine treated eyes exhibited significantly lower mean itching and conjunctival redness scores than the contralateral epinastine treated eyes, -0.19 (p = 0.003) and -0.52 (p < 0.001), respectively. Olopatadine treated eyes also exhibited significantly less chemosis -0.24 (p < 0.001), ciliary redness -0.55 (p < 0.001), and episcleral redness -0.58 (p < 0.001) than epinastine treated eyes.


CONCLUSIONS
Olopatadine is significantly more effective than epinastine in controlling itching, redness and chemosis associated with allergic conjunctivitis in the CAC model.
Lanier
Bobby Q
BQ
Fort Worth Allergy & Asthma Association, TX, USA. boblanier@askdrbob.com
Finegold
Ira
I
D'Arienzo
Peter
P
Granet
David
D
Epstein
Arthur B
AB
Ledgerwood
Greg L
GL
D000287:Administration, Topical; D000328:Adult; D000485:Allergens / Q000276:immunology; D018926:Anti-Allergic Agents / Q000008:administration & dosage*; D003233:Conjunctivitis, Allergic / Q000188:drug therapy* / Q000276:immunology; D003941:Diagnostic Techniques, Ophthalmological; D003984:Dibenzazepines / Q000008:administration & dosage*; D003990:Dibenzoxepins / Q000008:administration & dosage*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007093:Imidazoles / Q000008:administration & dosage*; D008297:Male; D008954:Models, Biological; D000069605:Olopatadine Hydrochloride; D009883:Ophthalmic Solutions; D011446:Prospective Studies; D016896:Treatment Outcome
D000485:Allergens; D018926:Anti-Allergic Agents; D003984:Dibenzazepines; D003990:Dibenzoxepins; D007093:Imidazoles; D009883:Ophthalmic Solutions; D000069605:Olopatadine Hydrochloride; C053090:epinastine