Mast cell stabilizer recommended for chronic ocular allergy

Wantagh, NY-Because of its ability to halt the allergic cascade, its long duration of action, and rapid relief of itching, nedocromil sodium ophthalmic solution 2% (Alocril, Allergan) is an excellent choice for the treatment of chronic allergic conjunctivitis, according to Jodi Luchs, MD, a private practitioner at South Shore Eye Care, Wantagh, NY.

Nedocromil is a very potent second-generation mast cell stabilizer that has a comprehensive effect on many of the cells and mediators in the allergic inflammatory cascade, said Dr. Luchs, who is also an assistant clinical professor of ophthalmology and visual sciences at Albert Einstein College of Medicine and is on the cornea service at Long Island Jewish Medical Center.

"It acts on these cells directly," Dr. Luchs said. "Because it is not an antihistamine, its effect on controlling this portion of the cascade is not a secondary effect due to blocking the release of histamine. The medication has a direct effect on the cells that are involved in this portion of the cascade, so it is very powerful in that regard.

"It is a very good drug for patients with chronic allergic symptoms, whether it be seasonal or perennial allergic conjunctivitis. To treat this type of condition we want a drug with a mechanism of action that is more comprehensive-one that acts at multiple points in the allergic inflammatory cascade in order to provide more control of this inflammatory response," Dr. Luchs said.

Co-existing dry eye He also observed that because many patients have coexisting dry eye and ocular allergy, any drug that would exacerbate the dryness and paradoxically increase the itching symptoms should be avoided.

"The last thing I want to do when prescribing an allergy medication is to make patients' dry eye symptoms worse. I recommend a medication that is useful in the setting of dry eye, so one can minimize the amount of drug needed during the day," he said.

"Nedocromil is well suited for that, offering a long duration of action. It is a true 12-hour drug," he added. "Patients don't have to keep putting medication on the ocular surface; this is helpful because a dry ocular surface can become irritated and more prone to toxic effects."

Some other ocular allergy medications are also applied twice a day but are recommended for use at shorter intervals, such as every 6 to 8 hours or 8 to 12 hours.

Contact lens use is another factor in the therapeutic choice, because many patients with allergy have difficulty wearing their contact lenses when their eyes become irritated and inflamed.

"Again, a drug should have a long duration of action and a comprehensive mechanism of action to shut down the allergic response and give patients complete relief throughout the day without the need to re-medicate when wearing contact lenses," Dr. Luchs said.

Rapid response may also be a basis for deciding whether to prescribe nedocromil or another agent. Although nedocromil relieves itching within a few minutes, antihistamines are slightly faster, and this could make a difference in some patients, Dr. Luchs said.

Epinastine HCl ophthalmic solution 0.05% (Elestat, Inspire Pharmaceuticals/ Allergan) is a newer agent that combines second-generation mast cell stabilizing activity as well as both H₁ and H₂ antihistamine activity, and it is effective in the same group of patients as nedocromil, Dr. Luchs said.

"These days I prescribe one of those two agents for many patients who have more than just fleeting allergy symptoms," he added.

Ultimately, the prescribing decision typically comes down to a patient-by-patient choice that involves all of the factors mentioned above, as well as a detailed history, careful examination and the patient's prior experience with other topical or systemic allergy medications.