April 25, 2000 -- As pollen season kicks into full gear, doctors have two new types of prescription eye drops to offer patients with red, itchy eyes caused by allergies. The two drugs, along with a third type that should be on drugstore shelves within a few weeks, are easier to use and provide faster pain relief than older medications, specialists say.
"More than 22 million people in this country have seasonal eye allergies," William Basuk, MD, an eye disease specialist with Scripps Memorial Hospital in San Diego, tells WebMD. "Their main complaint is itching."
Red, swollen, itchy eyes are caused by allergic conjunctivitis, which occurs when the membrane covering the white of the eye and the inside of the eyelid becomes inflamed. This happens after the membrane comes into contact with dust, pollen, pet dander, or other airborne allergens -- substances that are especially prevalent in the spring.
Pharmaceutical companies say the two new drugs -- Alocril, from Allergan Inc., and Zaditor, from CIBA Vision -- are an improvement over older drugs because they attack allergic symptoms in two ways instead of one. Most older drugs are either antihistamines, which block the action of histamine (the substance that causes itching, burning, redness, and swelling), or mast-cell stabilizers, which prevent mast cells (a type of blood cell) from releasing histamine.
Alocril and Zaditor are both antihistamines and mast-cell stabilizers. Zaditor also has a third action that helps quell allergic symptoms.
"It makes sense that medications that do both are best, but we have no solid studies yet that prove that," Basuk says. "But the new ones are more convenient; you use them twice a day, as opposed to four times a day, and they provide relief faster than the older drugs. It's pretty horrible to have to wait two weeks to get relief."
Antihistamines and mast-cell stabilizers were originally developed as alternatives to steroids, powerful medications that have serious side effects such as glaucoma, cataracts, and infection. In some cases, doctors will prescribe steroids for a short period for instant relief, and a newer medication for long-term use.
"In most cases, the symptoms of ocular allergies are mild to moderate," Basuk says, "but in a few severe cases, people can lose their vision. For them, these allergy medications are crucial in saving their sight."
The third new drug, Alamast, by Santen Inc., has been approved by the FDA and will be available in a few weeks. It is an improved mast-cell stabilizer, and also comes in drop form.
This drug should be used before symptoms start, because it takes a few days before the itching stops, Gregg J. Berdy, MD, an eye allergy specialist and clinical instructor at Washington University School of Medicine in St. Louis, tells WebMD. He was involved in the clinical testing of Alamast.
"It's also the most comfortable drug of its kind because it doesn't sting," he says.
Before prescribing any medications, doctors must confirm that the conjunctivitis is due to an allergy rather than being the symptom of another problem, such as an infection. The doctor may first try prescription-strength antihistamines. If these fail to quell the inflammation and itching, the next step could be one of these new drugs.
Before calling the doctor, though, there are some other things allergy sufferers can try, Berdy advises.
"Begin by using over-the-counter tear substitutes and cold compresses," he says, "and some people will benefit from over-the-counter antihistamines used in conjunction with the artificial tears."
- New drugs are available for allergic conjunctivitis that are faster acting and easier to use, but further studies are needed to prove whether they are more effective than older drugs.
- The new drugs, along with older antihistamines and mast-cell stabilizers, are alternatives to steroids, which are highly effective but have serious side effects.
- If symptoms of allergic conjunctivitis -- redness, swelling, tearing, and itching -- are mild to moderate, try applying cold compresses to the eyes and using over-the-counter medications (oral antihistamines, artificial tears) before calling the doctor.