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Generic glaucoma medications cut costs, but usage should be monitored
With a glaucoma combination drug recently going off-patent and a prostaglandin analogue set to go off-patent in a few years, physicians and patients may have more options for potential cost-effective, IOP-lowering generic medications.
However, when choosing generic drugs over brand names, physicians should take care to observe patients’ reactions to the differences in the formulations and other factors.
“More generic medications may offer some cost savings to some patients, but will also likely lead to more confusion for patients,” Louis B. Cantor, MD, said. “Often, different generic medications look different than the branded medications a patient may be used to.”
Cosopt (dorzolamide HCI, timolol maleate ophthalmic solution, Merck) has recently gone off-patent, while Xalatan (latanoprost, Pfizer) is set to be available in generic form in 2011.
In addition, Hi-Tech Pharmacal recently received final approval from the U.S. Food and Drug Administration for dorzolamide ophthalmic solution 2%, the generic for Trusopt ophthalmic solution 2% (Merck).
Cost savings and compliance
Generics may be helpful for patients who have cost barriers to obtaining medication, Dr. Cantor, an OSN Glaucoma Section Member, said. Generic medications are often on the first price tier of managed health care plans.
“That difference alone may not be sufficient for patients who do not obtain their medications due to cost. In addition, most compliance issues are related to patient difficulties in remembering to use and using their medications properly, not necessarily problems related to the cost of obtaining their medications,” Dr. Cantor said.
“The recent economic downturn may make it difficult for patients to obtain medications,” James C. Tsai, MD, said. Given those difficulties, it is especially helpful that the combination drug Cosopt is going off-patent because it reduces the number of total medications needed.
“Patients are feeling the economic crunch,” Dr. Tsai, an OSN Glaucoma Section Member, said. “We know that they’re delaying coming in to see their physician and paying for office visits and medications. I think every little bit of cost savings helps.”
Whether the generics will assist with overall patient compliance is doubtful, he said. Dr. Tsai and colleagues conducted a study looking at reasons for patient noncompliance in 2003. They factored out cost because patients in the study had health insurance, and they found that patients still had 71 distinct reasons for noncompliance. The factors were varied and represented the full scope of patients’ busy lives.
Efficacy
Efficacy issues could arise from new generic formulations because of the basic makeup of different formulations. Generic drugs must show only formulary equivalency to brand medications, Dr. Cantor said. They do not have to be compared with their brand equivalents in clinical trials.
Generic formulations are also not required to have the same excipient ingredients as brand formulations and may differ in ingredients besides the active molecule, including buffers, PH adjusters, preservatives and vehicle, Dr. Cantor said.
Because of those reasons, efficacy with the new formulations of key glaucoma drugs must be carefully monitored, according to Drs. Cantor and Tsai. Until the full range of the effects of generic medications is known, tolerability and IOP should be monitored on a case-by-case basis. – by Erin L. Boyle
Reference:
- Tsai JC, McClure CA, Ramos SE, Schlundt DG, Pichert JW. Compliance barriers in glaucoma: a systematic classification. J Glaucoma. 2003;12(5):393-398.
- Louis B. Cantor, MD, can be reached at Indiana University School of Medicine, Eugene and Marilyn Glick Eye Institute, 702 Rotary Circle, Indianapolis, IN 46202; 317-274-8485; fax: 317-278-1007; e-mail: lcantor@iupui.edu.
- James C. Tsai, MD, can be reached at Department of Ophthalmology and Visual Science, Yale University School of Medicine, 40 Temple St., Suite 1B, New Haven, CT 06510; 203-785-7233; fax: 203-785-7694; e-mail: james.tsai@yale.edu.
