Follow advances in pharmacology

Dr. Bartlett, professor of optometry and professor of pharmacology at the University of Alabama at Birmingham (UAB), "dispensed" pearls to attending optometrists on a variety of topics.

He began with a synopsis of a novel topical ocular anesthetic, lidocaine hydrochloride ophthalmic gel 3.5% (Akten, Akorn).

Generics for glaucoma patients

Reviewing available generic glaucoma drugs, he said that generic brimonidine 0.15% and 0.2% are AT-rated; Timolol GFS 0.5% (Falcon) is a generic version of Timoptic XE 0.5% (Merck) and is AB-rated; Istalol (ISTA), preserved with potassium sorbate, is equivalent to timolol maleate solution; and generic acetazolamide is equivalent to Diamox (Lederle Laboratories) and 37% less expensive.

Dr. Bartlett recommended that optometrists not use a generic formulation of the corticosteroid prednisolone acetate ophthalmic suspension 1.0% made by Falcon. However, Alcon's Omnipred (formerly known as Econopred Plus), another generic prednisolone acetate ophthalmic suspension, has been found to be equivalent to Pred Forte (Allergan) in a head-to-head comparison in postsurgical cataract patients.

Another topic he discussed was the adverse ocular effects of systemic medications. The drug hydroxychloroquine sulfate (Plaquenil, Sanofi-Aventis), used to treat lupus and rheumatoid arthritis, has well-known ocular effects, such as retinal and macular toxicity.

What is less known, however, is that recent research indicates that patients do not need to be followed as frequently as was once believed, he said. Even high-risk patients who have been taking this medication for more than 5 years and have other risk factors do not need to be seen more than once a year, rather than every 4 to 6 months.

Two ocular anti-infectives that offer efficacy against methicillin-resistant Staphylococcus aureus (MRSA) infections in the eye are trimethoprim and tobramycin. Trimethoprim, the more effective of these, can be found in the formulation of polymyxin B sulfate and trimethoprim ophthalmic solution (Polytrim, Allergan).

Dr. Bartlett noted that new studies seem to indicate that another anti-infective agent, besifloxacin ophthalmic suspension 0.6% (Besivance, Bausch + Lomb), also appears to be very effective against MRSA keratitis. This would be an off-label use of the drug, because it is currently FDA-indicated for the treatment of bacterial conjunctivitis.

Emerging off-label use

An emerging off-label use of besifloxacin is in the treatment of bacterial keratitis. Many optometrists and ophthalmologists are now using besifloxacin as their drug of first choice despite the lack of published studies supporting this approach, he said.

Another important development in ocular pharmacology is the recent approval of ganciclovir ophthalmic gel 0.15% (Zirgan, Bausch + Lomb). This approval represents a major advance in the treatment of herpes simplex virus epithelial keratitis.

"It's very nontoxic, so we have fewer side effects," Dr. Bartlett said. "These attributes and its comfort in the eye are due to its action; the drug [affects] DNA synthesis only in viral cells, leaving normal, healthy cells untouched," he said.