Original and generic latanoprost for the treatment of glaucoma and ocular hypertension: Are they really the same?

Summary: We compared the intraocular pressure (IOP)-lowering effect and safety profile of latanoprost (Xalatan) with its generic variant, Glautan (Unipharm, Tel Aviv, Israel). After 1 and 4 weeks of treatment, a randomized, prospective, cross-over comparison was carried out that included patients with open-angle glaucoma or ocular hypertension, either naïve or treated and well-controlled, who were attending the Department of Ophthalmology, Tel Aviv Medical Centre, Tel Aviv, Israel, between May 2010 and November 2012. After a 3-week washout period for the medicated subjects, the participants were randomized to 4 weeks of treatment with either Xalatan or Glautan once every evening and then, after a 3-week washout period, crossed-over to the other treatment for an additional 4 weeks. Efficacy was expressed by a change in intraocular pressure at three designated hours of the day after 1 week and 1 month of treatment, and tolerability was determined by ocular side-effects as reported by the patient in a questionnaire. A total of 19 patients (mean age at initial diagnosis 66 ± 9 years, 14 females) were enrolled, of whom 17 had bilateral open-angle glaucoma and two had unilateral disease. Both drugs lowered intraocular pressure after 1 week and 1 month (P = 0.06 and P = 0.04, respectively) of treatment. Xalatan had a tendency of greater efficacy than Glautan both after 1 week and 1 month, but the difference was not statistically significant (P =0.69 and P = 0.34, respectively). Drug safety was similar for Xalatan or Glautan, but more ocular side-effects were reported after treatment with Glautan (21 vs 12 for Xalatan, P = 0.06).