Patient experience of the transition from Xalatan to generic latanoprost

The Use of Generic Medications for Glaucoma

The use of generic medicines has grown considerably in recent years providing considerable cost savings. In England, generic items represented 11.7% of prescriptions for glaucoma and ocular hypertension in 2009, increasing to 55.2% of prescriptions in 2018. Generics can be brought to the market quickly and at low cost as manufacturers are not required to repeat animal or clinical research on active ingredients already approved for safety and efficacy. Although there is no regulatory requirement for studies comparing branded and generic eye drops, several randomised crossover studies have been performed comparing branded and generic prostaglandin analogues. While most have shown similar intraocular pressure lowering, studies are of short duration and have not evaluated visual field endpoints. Furthermore, differences in inactive ingredients, pH, viscosity, levels of particulate matter, and degradation over time have been reported. Other potential problems with generic eye drops include differences in bottle design affecting adherence, problems with supply, and the possibility that reduced revenue for innovator companies will lead to reduced investment in new drug development. This article reviews the potential advantages and disadvantages of generic antiglaucoma medications.

Generics versus brand-named drugs for glaucoma: the debate continues

There are three options for a given class of drugs, including brand name drugs, generic and branded generic drugs. Brand name drugs are costlier as compared to generic and branded generic drugs because they are innovator molecules developed by a company after many years of research and come into the market with a patent, whereas branded generic drugs are produced by a different company once the patent of innovator company expires. Given that glaucoma is a chronic, largely asymptomatic disease, the choice of drugs is extremely important: the duration of medication is often lifelong, and the cost of drugs, side effects and efficacy affect compliance and adherence to therapy. This review is a brief overview of the available brand name and branded generic drugs for the management of glaucoma, in terms of efficacy and side effect profiles. It also aimed to guide rational and pragmatic drug choices in different clinical scenarios.

Intraocular pressure with rebound tonometry and effects of topical intraocular pressure reducing medications in guinea pigs

AIM

To investigate the intraocular pressure (IOP) of adult guinea pig eyes with rebound tonometry (RBT), and assess the effects of four distinctive topical IOP reducing medications including Carteolol, Brimonidine, Brinzolamide and Latanoprost.

METHODS

The IOPs of twenty-four 12-week-old guinea pigs (48 eyes) were measured every two hours in one day with RBT as baselines. All the animals were then divided into four groups (Carteolol, Brimonidine, Brinzolamide and Latanaprost groups, n=6). The IOPs were measured and compared to the baseline 1, 2, 3, 5, 7, 9, 15 and 24h after treatment.

RESULTS

The mean baseline IOP of 24 guinea pigs (48 eyes) was 10.3±0.36 mm Hg (6-13 mm Hg) and no binocular significant differences of IOPs were observed (t=1.76, P>0.05). No significant difference of IOP in Carteolol group at each time point was observed before and after treatment (t=1.48, P>0.05). In Brimonidine group, IOP was 2.2±1.9 mm Hg lower than the baseline after one hour (t=3.856, P=0.003) and lasted for one hour. In Brinzolamide group, IOP was 1.4±1.1 mm Hg lower than the baseline after one hour (t=4.53, P=0.001) and lasted for 7h and the IOP declined most at 3h. In Latanaprost group, IOP was 2.1±1.3 mm Hg lower than the baseline after one hour (t=6.11, P=0.001) and lasted for one hour.

CONCLUSION

The IOP of guinea pig eyes is relatively stable compared to human eyes. In four reducing IOP medications, no significant effect of Carteolol is observed. Brinzolamide has the longest duration, while the Brimonidine has the shortest duration and the maximum level of treatment.

Manchester iStent study: 3-year results and cost analysis

PurposeTo evaluate the safety, efficacy, and the cost of combined phacoemulsification and single iStent insertion in open angle glaucoma (OAG) at 3-years follow-up.MethodsThis was a prospective, uncontrolled, interventional case series. All subjects underwent single iStent implantation combined with cataract surgery by a single surgeon and were followed up over 3 years. Primary outcome measures were the reduction in intraocular pressure (IOP) and number of glaucoma drops at 1, 2, and 3 years. The costs of the procedure vs the cost of continuation of glaucoma drops were calculated and compared in patients who completed 3-years follow-up.ResultsForty-one patients were included in the study and thirty-six patients completed 3-years follow-up. Mean pre-op IOP was 21.2 mm Hg on 2.1 medications. Mean IOP was reduced to 15.9 mm Hg on 0.5 drops, 16.1 mm Hg on 1.0 drops, and 17.1 mm Hg (P<0.001) on 1.3 drops (P<0.001) at 1, 2, and 3 years, respectively. The overall cost of combined cataract surgery and iStent was estimated to be £829.32 more in total than conservative management with brand name eye drops over 3 years (£7.70 per patient per year) and £14 176.9 more if generic drops were used. (£131.3 per patient per year).ConclusionsCombined phaco-iStent proved to be a safe and effective way of managing patients with OAG over our 3-year follow-up period. The cost-effectiveness of the procedure may vary depending on whether brand name or generic eye drops are used.