A Comparison of Xalatan (Latanoprost) to Apo-latanoprost and Co-latanoprost in the Treatment of Glaucoma

Since the introduction of Xalatan generic versions of latanoprost have entered the Canadian marketplace such as Apo-latanoprost (Apotex Inc.), Co-latanoprost (Cobalt Pharmaceuticals Co.) and Sandoz latanoprost (Sandoz Canada Inc.). The exact formulation of the different preparations of latanoprost may differ between manufacturers, although the active ingredient itself is not supposed to vary within a 15% tolerance. In a topical ocular medication in a multi-dose dispenser, the stability of the drug and its ability to penetrate the cornea into the eye may affect the efficacy of the drug. There are no clinical trials to compare the efficacy of generic versions of latanoprost to Xalatan, nor are there any clinical trials comparing efficacy between the different generic versions. Empirical evidence based on clinical experience suggests that at least some of the generic versions of latanoprost may not be as effective as the branded version (Xalatan). Intraocular pressure is often observed to increase when switching from a branded to generic version of latanoprost, but the opposite is rarely if ever observed. The purpose of this study will be to compare the efficacy of Xalatan to two of the most popular generic versions of latanoprost available in Canada (Apo-latanoprost and Co-latanoprost).