Epinastine hydrochloride ophthalmic solution 0.05% is a reliable, fast-acting treatment for patients with itching associated with allergic conjunctivitis.
In addition to relieving ocular itching associated with allergic conjunctivitis, research has indicated that the drug also improves hyperemia, chemosis, tearing, and lid swelling when the drug is used off-label to treat these symptoms.
Dr. Milner explained that the medication's twice-daily dosing is easy for patients to work into their schedules. He advises patients to instill the drug in the morning and then again in the evening before bedtime.
For patients who wear contact lenses, he instructs them to instill epinastine and wait 30 minutes before putting in their contact lenses and then again at night after removing the lenses.
In addition to the twice-daily dosing, the prescribing information recommends that treatment should be continued throughout the period of exposure (i.e., until the pollen season is over or until exposure to the offending allergen is terminated), even when symptoms are absent.
Because epinastine is a multi-action formulation, it works better for patients than drugs that contain only an antihistamine. In Dr. Milner's opinion, the multi-action nature of the drug is probably its greatest advantage.
"There are numerous effective ophthalmic drops on the market," he said. "However, the multi-action drugs have a better effect compared with drugs that are only antihistamines or mast cell stabilizers. This makes for happier patients.
"Epinastine is extremely well tolerated by patients, with few side effects," Dr. Milner added.
He also likes that epinastine is one of the few multi-action allergy drops that block both H1 and H2 histamine receptors.
"When H2 receptors are blocked, there is a greater reduction of eyelid swelling," he said.
Another advantage of epinastine, indicated by the results of animal studies, is that the drug may be less likely to cause dry eye. This is important to Dr. Milner for his patients with dry eye and allergic conjunctivitis.
Finally, epinastine has a rapid onset of action. Most patients have an initial response in about 15 minutes or less, and the action continues for 8 to 12 hours, Dr. Milner said.
Epinastine works very well for most patients who present with allergic conjunctivitis, Dr. Milner said. Typically, these patients present with a history of dry eye and blepharitis, as well as allergic symptoms.
Dr. Milner showed his confidence in epinastine by prescribing the drug recently for a patient with a difficult history of ocular surface disease. The patient was a 21-year-old man who had been treated with numerous topical drops by several ophthalmologists but whose condition had not achieved satisfactory results and continued to present chronic recurrent conjunctivitis. The patient had a history of asthma, resulting in atopy, borderline dry eye, and blepharitis. Dr. Milner prescribed cyclosporine ophthalmic emulsion 0.05% (Restasis, Allergan) twice daily and epinastine twice daily.
In most cases, patients achieved the desired results, he said.
"I prefer the multi-action drugs, and I like epinastine because it is well tolerated and efficacious," Dr. Milner concluded. "It stabilizes mast cells, has an antihistamine effect (H1 and H2 blockade), stops recruitment of other inflammatory cells, such as the eosinophils, and may not have the drying effect seen with other drugs."
Mark S. Milner, MD
Dr. Milner is a consultant to Allergan and Inspire Pharmaceuticals.