Eye care professionals looking to improve their patients’ adherence to glaucoma medications might have a new—and surprisingly simple—trick up their sleeves. In a recent longitudinal cohort analysis, the results of which were published online in Ophthalmology, researchers found that switching to a generic drug improved adherence by as much as 25%.1 

Medication adherence is a major problem, considering more than half of glaucoma patients do not take their medications as prescribed.2 The cost of glaucoma medication could be part of the problem, say researchers from the University of Michigan Medical School and University of Michigan College of Pharmacy. 

“Individuals’ out-of-pocket costs for glaucoma medications can exceed $100 per month, and the high drug cost may deter patients on a tight budget from consistently buying and taking their medications as prescribed,” says Joshua D. Stein, MD, associate professor of ophthalmology and visual sciences at the University of Michigan Kellogg Eye Center and lead author of the study. “If clinicians suspect that a patient is struggling with medication adherence, it may be a good idea to switch them from a brand name to a generic drug.”

The 2011 release of generic latanoprost gave patients a cheaper option—and researchers the opportunity to find out if cost was in fact a motivating factor. 

Dr. Stein and colleagues examined claims data from 8,427 glaucoma patients for the 18 months before and after generic latanoprost became available. They found that medication adherence improved on average among all patients who switched to the generic, but the rate of adherence differed among certain subgroups. Those who were on bimatoprost prior to switching to generic latanoprost increased adherence from an average 47% to 61%; those who switched from travoprost increased adherence from 43% to 54%. 

The study also showed the subset of black patients who switched to the generic drug had a substantial improvement in adherence compared to blacks who remained on brand-name products.

“It’s reassuring to find that switching patients to more affordable, generic drugs could be an effective solution for a subgroup of patients who have difficulty with adherence,” Dr. Stein says.

One finding that the researchers could not explain: A considerable number of patients discontinued glaucoma drug use altogether when generic latanoprost became available.

1. Stein J, Shekhawat N, Talwar N, Balkrishnan R. Impact of the introduction of generic latanoprost on glaucoma medication adherence. Ophthalmology. 2015 Feb
2. [Epub ahead of print.]
2. Schwartz GF, Quigley HA. Adherence and persistence with glaucoma therapy. Surv Ophthalmol. 2008 Nov;53 Suppl1:S57-68.