Glaucoma: Glaucoma editor’s corner of the world
December 2011
by Faith A. Hayden
EyeWorld Staff Writer
The advent of generic latanoprost is a dramatic development in glaucoma therapy. The availability of generic prostaglandins will give patients and doctors a more affordable option but raises the question of whether the generic alternatives will be as safe and effective as the branded products. This month we are fortunate to have two glaucoma experts—Nathan Radcliffe, M.D., and L. Jay Katz, M.D.—review what defines a generic and how to evaluate generics in our glaucoma patients. Both doctors stress the importance of follow-up if a patient is switched to a generic prostaglandin. Although the active ingredients must be present in the same concentration as the branded product, some of the inactive ingredients may be different. Patients on generics need to be checked for pressure but also questioned about comfort and tolerability since this may affect compliance in a chronic disease like glaucoma.
Patents run out eventually and this creates an adjustment in the marketplace. When this happened with timolol, the prostaglandins were becoming available, and they have been the most effective and safest glaucoma medications we have had. Hopefully, there are other new breakthrough treatments around the corner that will further improve glaucoma care.
—Reay Brown, M.D., glaucoma editor
Physicians sometimes turn a skeptical eye toward generic versions of brand name products, and with good reason. Historically, not every generic medication in ophthalmology has performed as well as its branded counterpart. For example, prednisolone wasn’t as effective at controlling inflammation as branded Pred Forte (Allergan, Irvine, Calif.), and diclofenac, which is the generic version of Voltaren, had instances of corneal melts in patients, leading to withdrawal from the market, said L. Jay Katz, M.D., Wills Eye Institute, Philadelphia.
So naturally when branded Xalatan (Pfizer, New York), which reduces elevated intraocular pressure in patients with open-angle glaucoma or ocular hypertension, went to generic latanoprost in March, doctors had questions.
“Generics can often work well, but sometimes there’s a question of efficacy and tolerability,” said Dr. Katz.
“The brand name and generic products are not identical. One is called Xalatan and the other is called latanoprost,” said Nathan Radcliffe, M.D., assistant professor of ophthalmology, Weill Cornell Medical College, New York. “The bottle is going to look different so to your patients, there’s a difference, and there may be confusion. Latanoprost doesn’t have the same price, which is a difference.”
Different bottle designs can be problematic for some people, especially glaucoma patients who tend to be older and may struggle with drop delivery due to arthritis, tremors, and other mobility issues.
“Does [the bottle] deliver the drug the same way?” asked Dr. Katz. “Does too much come out or does too little come out? Is it easy for someone who’s 90 years old to get the drop out?”
Regulations don’t govern drop administration, bottle design, or rigidity of the bottle, he said, so in reality there can be noticeable differences between the generic and branded design. In terms of the specific formulation, though, both must include the same active ingredients in the same concentration, as well as the same preservatives. According to spokesmen for the FDA, there is no qualitative or quantitative difference between the two versions.
“Since the product is a solution and has the same active and inactive ingredients, there would be no difference in performance,” said Lisa Kubaska, L.C.D.R., U.S. Public Health Service, FDA. “We assure that a generic version of any product works the same in the body.”
Dr. Radcliffe would prefer to see data from human trials that supports the safety and efficacy of generic ophthalmic medications. Manufacturers are not required to release the concentrations of the inactive ingredients of branded medications, he said.
“Generics are typically created using reverse engineering practices,” he said. “Since you’re not recreating it from the identical recipe and manufacturing process, there may be some small differences.”
A number of different companies produce generic latanoprost including Apotex (Weston, Fla.), Bausch + Lomb (Rochester, N.Y.), Falcon Pharmaceuticals (affiliate of Alcon, Fort Worth, Texas), Greenstone (Peapack, N.J.), and Mylan (Canonsburg, Pa.). The problem for patients and physicians is neither know which company’s version of the product will end up in patients’ eyes; it may change month to month by the filling pharmacy.
“We don’t have any control over that,” said Dr. Katz. “Patients may do fine or there may be an issue with tolerability. There may be side effects they didn’t have before. Perhaps there’s a chance it might not be as effective. The only way to know is to try it.”
At least one major positive difference between the two drugs is cost. Generally speaking, the generic is much cheaper than the branded, although exact price varies widely depending on location and insurance plan. “The cheapest I’ve heard was around $15 a bottle totally out of pocket,” said Dr. Katz. “That’s with no copay.”
If you’re considering switching a patient to latanoprost, it’s important to have a direct conversation with him or her about what you know and what you don’t know about the drug. Not every patient will want the generic version. Some may be totally opposed and insist on the branded.
“We don’t want to make assumptions regarding how much savings a patient will be getting, and we don’t want to assume that savings is something the patient is determined to pursue,” said Dr. Radcliffe. “We’ve got to talk to the patients.”
“Right now, if a physician writes Xalatan, a lot of people come back with the generic formulation anyway,” said Dr. Katz. “Many patients are willing to do that, but some people prefer not to use generics.”
If it turns out that a patient isn’t happy with the generic version for whatever reason, it’s probably best to switch him to a competitor in-brand. If the patient does switch medications, it’s a good idea to follow him a little more closely to make sure his pressure levels are controlled.
“If you’re switching the patient to a generic, you’ve got to think twice before you say, ‘I’ll see you in 6 months,’” said Dr. Radcliffe. “I believe the generic versions are safe. I believe there may be small differences we will learn about over the next few years.”
These differences could also be between generics. If they should all be lumped together under one headline remains to be seen.
“Are they all the exact same thing? I don’t think we know that,” said Dr. Katz. “They’ve been out such a short period of time that we can’t tell yet. We’re waiting to see some papers come out that are an independent analysis of the composition of each of the bottles, assuring us they are all pretty much the same.”
Editors’ note
Dr. Katz has financial interests with Alcon, Allergan, and Bausch + Lomb, among other companies. Dr. Radcliffe has financial interests with Alcon and Allergan.
Contact information
Katz: ljaykatz@gmail.com
Radcliffe: drradcliffe@gmail.com
