Efficacy and safety of ketotifen fumarate 0.025% in the conjunctival antigen challenge model of ocular allergic conjunctivitis

Am J Ophthalmol. 2003 Dec;136(6):1097-105. doi: 10.1016/s0002-9394(03)00708-6.


Purpose: 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.

Design: 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.

Publication types

  • Clinical Trial
  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Allergens / adverse effects
  • Anti-Allergic Agents / administration & dosage*
  • Antigens / adverse effects
  • Conjunctiva / blood supply
  • Conjunctiva / drug effects
  • Conjunctivitis, Allergic / chemically induced
  • Conjunctivitis, Allergic / drug therapy*
  • Double-Blind Method
  • Female
  • Histamine H1 Antagonists / administration & dosage*
  • Humans
  • Hyperemia / prevention & control
  • Ketotifen / administration & dosage*
  • Male
  • Middle Aged
  • Models, Biological
  • Ophthalmic Solutions
  • Pruritus / prevention & control
  • Safety


  • Allergens
  • Anti-Allergic Agents
  • Antigens
  • Histamine H1 Antagonists
  • Ophthalmic Solutions
  • Ketotifen