A forced choice comfort study of olopatadine hydrochloride 0.1% versus ketotifen fumarate 0.05%
Related Experiment Video
Updated: Aug 7, 2026

Use of the Operant Orofacial Pain Assessment Device (OPAD) to Measure Changes in Nociceptive Behavior
Published on: June 10, 2013
M N Artal1, J D Luna, M Discepola
1Fundación VER Casilla de Correo, Córdoba, Argentina.
Purpose:
To compare the ocular comfort of two ophthalmic anti-allergic agents: olopatadine hydrochloride 0.1% and ketotifen fumarate 0.05%.
Subjects And Methods:
In a double-masked, multi-centered, randomized trial, 80 subjects were asked to make a 'forced choice' based on ocular comfort between one drop of olopatadine hydrochloride 0.1% instilled in one eye and one drop of ketotifen fumarate 0.05% instilled in the contralateral eye. At one site, the incidence of adverse reactions was also reported.
Results:
All subjects (100%) selected olopatadine as the more comfortable formulation. One site (n = 35) reported a 49% incidence of moderate burning and a 49% incidence of mild burning after ketotifen instillation. One subject (2% of population) at this site experienced no ocular discomfort with ketotifen. There were no reports of discomfort associated with olopatadine instillation.
Conclusion:
Olopatadine is a more comfortable ophthalmic preparation than ketotifen.
Related Concept Videos
Open Angle Glaucoma: Treatment
Drugs such as carbonic anhydrase inhibitors, α2- and...
Ophthalmic Drug Delivery Systems

