RX PERSPECTIVE

Simbrinza: Combination drop without the beta-blocker

Brinzolamide and brimonidine in a single-dose bottle.

Gregory Katz, MD, is a glaucoma specialist practicing at Huron Ophthalmology out of St. Joseph Mercy Medical Center in Ann Arbor, Mich. His e-mail is glbjkatz@hotmail.com. Disclosure: Dr. Katz disclosed he is a speaker for and consultant to Alcon.

By Gregory Katz, MD

Simbrinza, a drug the FDA approved earlier this year for first or second line treatment of primary open-angle glaucoma or ocular hypertension, has, since hitting the market this spring, enhanced the treatment of glaucoma patients, including many of my own, as it reduces the medication burden in controlling IOP.

Combining a carbonic anhydrase inhibitor (brinzolamide 1.0%) and an alpha-2 adrenergic receptor agonist (brimonidine tartrate 0.2%) in a single-dose bottle, Simbrinza (Alcon, Fort Worth, Texas) is the only beta-blocker-free fixed-combination therapy for glaucoma available in the US market. It offers my glaucoma patients several distinct advantages. First, it has been shown to be highly efficacious, lowering IOP 5 to 9 mm Hg compared to baseline, a decrease of 21% to 35%.

PROBLEMS WITH BETA-BLOCKERS

Another advantage is that because it is beta-blocker free, Simbrinza can be used in a wider variety of patients. Beta-blockers are contraindicated in patients with asthma, severe COPD, sinus bradycardia, second- or third-degree heart block and severe congestive heart failure.

Beta-blockers can cause depression, impotence and hair loss. They can mask hypoglycemia and can exacerbate myasthenia. Topical beta-blockers have been shown to be less effective in lowering IOP in those already on oral beta-blockers.

CONVENIENCE FACTOR

Fixed combinations such as Simbrinza offer other advantages. These medications are more convenient for patients, requiring them to use fewer bottles and fewer drops per day than using the components individually. This likely will help increase compliance.

Additionally, Simbrinza exposes patients to fewer preservatives than other IOP-lowering agents because it uses fixed combinations rather than the individual components separately. Preservatives when used chronically in glaucoma medications have been shown to exacerbate ocular surface disease.

Also, Simbrinza eliminates the possibility of washout effect and it does not require the patient to wait five minutes between drops.

TRIAL RESULTS

Responses from my patients, as well as my experience in a three-month trial¹ — one of two involving more than 1,300 patients — indicate Simbrinza is safe and effective.

Adverse reactions in both three-month trials occurred in 3% to 5% of patients. In descending order of incidence, these were blurred vision, eye irritation, dysgeusia (bad taste), dry mouth and eye allergy. No serious adverse events were associated with Simbrinza in either of the clinical trials. The side effect profile of Simbrinza was similar to that of the individual components; neither trial identified any additional risks.

To date, the patients I have started on Simbrinza have responded with significantly lower IOP and are tolerating the medication well. I believe Simbrinza, because of its safety and efficacy profile, will become one of the most commonly utilized fixed-combination therapies to treat glaucoma in the United States. OM

REFERENCE

1. Katz G, Dubiner H, Samples J, Vold S, Sall K. Three-Month Randomized Trial of Fixed-Combination Brinzolamide, 1%, and Brimonidine, 0.2%. JAMA Ophthalmol. 2013 Apr 11. [Epub ahead of print]