Mast cell stabilizer offers daily relief for allergy sufferers

Boston-With the advances in anti-allergy medications that have taken place in the recent past, nedocromil sodium ophthalmic solution 2% (Alocril Ophthalmic Solution, Allergan) fills a niche for those patients who do not find relief with the newest combination antihistamine/mast cell stabilizers, Michael Raizman, MD, told Ophthalmology Times.

"The most widely used anti-allergy agents are the newer combination antihistamine/mast cell stabilizers, namely, olopatadine HCl (Patanol Ophthalmic Solution, Alcon Laboratories), azelastine HCl (Optivar Ophthalmic Solution, MedPointe Healthcare), ketotifen fumarate (Zaditor Ophthalmic Solution, Novartis Pharmaceuticals), and epinastine HCl (Elestat, Allergan). All are very effective and useful for most types of allergies," explained Dr. Raizman, associate professor of ophthalmology, Tufts University School of Medicine, director of the cornea service, New England Eye Center, Boston.

"In my opinion, however, all of these drugs are relatively weak mast cell stabilizers in humans in the clinical setting. In the real world, these drops work best as antihistamines," he continued.

"Nedocromil is a mast cell stabilizer that prevents mast cells from degranulation in response to contact with allergens," Dr. Raizman said. "Cromolyn sodium (Crolom Sterile Ophthalmic Solution, Bausch & Lomb), the original mast cell stabilizer, is much less effective compared with nedocromil."

Most of his patients who have seasonal allergic conjunctivitis have ocular itching for a short period when the pollen counts are elevated. They do extremely well with one of the combination antihistamine/ mast cell stabilizers, and they do not need an additional mast cell stabilizing agent. However, he noted, those patients who have perennial conjunctivitis (allergies to dust and dander) do not necessarily achieve relief with the combination antihistamine/mast cell stabilizers.

"In that case, I will prescribe nedocromil for daily use. The patients then can use one of the newer antihistamines on bad days when flare-ups of symptoms occur," Dr. Raizman explained.

The same approach is true, Dr. Raizman noted, for patients who have more severe allergic conditions that are less common, such as atopic conjunctivitis and vernal conjunctivitis.

"Atopic conjunctivitis is chronic conjunctivitis in association with atopic dermatitis such as eczema; these patients often have chronic rhinitis and asthma. Vernal conjunctivitis occurs in children and young adults and flares up severely in the spring but can also be present year-round.

"The patients with atopic, vernal, and perennial conjunctivitis do well with daily mast cell stabilization over the long term. These patients will use nedocromil every day," Dr. Raizman explained.

A major advantage of nedocromil is its safety profile. "There are no side effects. The patients tolerate this drug very well," he said.

An interesting point about nedocromil is that in some patients it seems to work very quickly to control symptoms of allergy, Dr. Raizman commented.

"The speed with which it works is much quicker than the speed of the mast cell stabilizing effect. This drug, like many of the allergy drugs, has properties that we do not fully understand. Certain patients take 1 or 2 weeks to have any benefit from the drug, and others have an immediate benefit," he said.

Patient care

Dr. Raizman described how he approaches a patient with vernal conjunctivitis. When a child presents in the spring and is using a topical antihistamine, but is still experiencing a great deal of itching on a daily basis, Dr. Raizman begins with an initial prescription of nedocromil four times a day. At the same time, he instructs the patient or parents to continue with the topical antihistamine.

"As the condition begins to come under better control, I would then reduce the nedocromil to twice daily administration on a chronic basis," he explained.

In an adult who presents with atopic disease year-round, the patient is allergic to dust and animal dander, and has the resultant itchy eyelids, blepharitis, and eczema of the eyelids, Dr. Raizman prescribes nedocromil twice a day indefinitely. He will also prescribe a topical antihistamine if needed. He also noted that he would consider the use of topical steroids for severe flare-ups on a limited basis.