Efficacy and safety of ketotifen fumarate 0.025% in the conjunctival antigen challenge model of ocular allergic conjunctivitis.
OBJECTIVE
To determine the duration of action of ketotifen 0.025% eye drops vs placebo taken as single or multiple doses in an allergen challenge model.


METHODS
Two randomized, multicenter, double-masked, contralateral placebo-controlled studies, one a single-dose and one a multiple-dose study.


METHODS
Two conjunctival provocation tests (CPTs) were initially conducted to confirm reproducibility of subject responses in both studies. Subjects in study 1 (n = 87) received single doses of ketotifen in one eye and placebo in the other 15 minutes, 6 hours, and 8 hours before CPT. Subjects in study 2 (n = 85) received ketotifen or placebo once 8 hours before CPT. Single-dose efficacy results were used to further qualify a subject as a responder. Responders were re-randomized to a 4-week twice daily dosing regimen with a CPT 8 hours after the final dose. In both studies, ocular symptoms were assessed at three time points 3 to 15 minutes after challenge. There were no significant differences in adverse events between groups.


RESULTS
For both studies, ocular itching and vascular injection were significantly reduced (P <.003) at all time points after instillation of ketotifen, with a maximum reduction at 7 minutes postchallenge. In study 2, chemosis, tearing, and lid swelling were also assessed and were significantly reduced (P <.008) after instillation of ketotifen.


CONCLUSIONS
Ketotifen 0.025% eye drops were safe and statistically effective in preventing ocular itching, injection, and other signs and symptoms of allergic conjunctivitis at 15 minutes, 6 hours, and 8 hours after a single dose and at 8 hours after the final dose of a 4-week twice daily regimen.
Greiner
Jack V
JV
Schepens Eye Research Institute, Harvard Medical School, Boston, Massachusetts, USA.
Mundorf
Thomas
T
Dubiner
Harvey
H
Lonsdale
John
J
Casey
Richard
R
Parver
Leonard
L
Kapik
Barry M
BM
Shams
Naveed B K
NB
Abelson
Mark B
MB
D000328:Adult; D000368:Aged; D000485:Allergens / Q000009:adverse effects; D018926:Anti-Allergic Agents / Q000008:administration & dosage*; D000941:Antigens / Q000009:adverse effects; D003228:Conjunctiva / Q000098:blood supply / Q000187:drug effects; D003233:Conjunctivitis, Allergic / Q000139:chemically induced / Q000188:drug therapy*; D004311:Double-Blind Method; D005260:Female; D006634:Histamine H1 Antagonists / Q000008:administration & dosage*; D006801:Humans; D006940:Hyperemia / Q000517:prevention & control; D007665:Ketotifen / Q000008:administration & dosage*; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D009883:Ophthalmic Solutions; D011537:Pruritus / Q000517:prevention & control; D012449:Safety
D000485:Allergens; D018926:Anti-Allergic Agents; D000941:Antigens; D006634:Histamine H1 Antagonists; D009883:Ophthalmic Solutions; D007665:Ketotifen