April 2015

 

NEWS & OPINION

 

Pharmaceutical focus

Weathering the allergic conjunctivitis storm


by Maxine Lipner EyeWorld Senior Contributing Writer

 
   
Allergic cascade

Allergic cascade Source: Richard L. Lindstrom, MD

Understanding the umbrella of treatments

For all too many, April is the time of year when ocular allergies are brewing. Such allergies are common, said Richard L. Lindstrom, MD, adjunct professor emeritus, University of Minnesota, Minneapolis. Roughly 50 to 60 million Americans have allergic conjunctivitis, and (of those) 90% are seasonal, 5% are perennial, and a small number are atopic or vernal, Dr. Lindstrom said. Whether patients have seasonal allergic conjunctivitis or the year-round cousin, perennial allergic conjunctivitis, itching is one of the overriding symptoms, he said. Typically dry eye patients complain of a gritty foreign body sensation that gets worse later in the day, and those with blepharitis have some itching but more of a burning sensation. For patients with allergic conjunctivitis, the sensation is of itching. This is often located nasally right over the caruncle, because the caruncle is lymphatic tissue and its loaded with mast cells that release histamine, he said, explaining that it is the histamine that itches.

Edward J. Holland, MD, professor of ophthalmology, University of Cincinnati, finds that in managing allergic conjunctivitis patients, the severity of symptoms comes into play. There are patients who have mild disease, and they typically can be managed with some of the over- the-counter medications, whether its an antihistamine or a mast cell stabilizer, Dr. Holland said. We base our treatment on the symptoms. Patients with short-term seasonal allergic conjunctivitis can get by with over-the-counter topical anti- histamine or mast cell stabilizers, he said. Typically, however, patients who go to see an ophthalmologist have either severe or chronic symptoms and are looking for another treatment option.

Combination treatment

The combination antihistamine/mast cell stabilizers are the first-line therapy for anyone with significant symptoms, Dr. Holland said. This class of medication is more effective than either a mast cell stabilizer alone or an antihistamine alone. Dr. Lindstrom concurs, explaining that these are a natural, given the pathophysiology of allergic conjunctivitis. We have mast cells and eosinophils in the conjunctiva and they release histamine and some other cytokines, bradykinin, slow-reacting substance A, and some prostaglandins, Dr. Lindstrom said. But the primary ideology is eosinophil and mast cell-releasing histamine causing severe itching as the primary symptom. While there are individual drops that are just mast cell stabilizers and those that are just antihistamines, in Dr. Lindstroms view there is no reason not to use a combination agent. Of these the 3 most commonly prescribed are Patanol (olopatadine hydrochloride ophthalmic solution 0.1%, Alcon, Fort Worth, Texas), Pataday (olopatadine hydrochloride ophthalmic solution 0.2%, Alcon), and Bepreve (bepotastine besilate ophthalmic solution 1.5%, Bausch + Lomb, Bridgewater, N.J.), he said. I personally find these 3 drops to be equivalent in their efficacy, Dr. Lindstrom said.

Dr. Holland finds that choosing between these often comes down to patient preference with regard to dosing. Pataday is administered once a day versus twice a day for Patanol and Bepreve. Lastacaft (alcaftadine, Allergan, Irvine, Calif.) also has once-a-day dosing. While Dr. Holland views this as quite effective, it can be a bit more uncomfortable for some patients, in his experience. I think patients notice a bit more sting with that one than some of the others, Dr. Holland said. But I think theyre all quite effective. He finds that all of these prescription combination agents perform better than their one non-prescription counterpart Zaditor (ketotifen fumarate ophthalmic solution, Novartis, Basel, Switzerland). Dr. Lindstrom views Zaditor as quite effective as an over-the- counter agent, but finds that most patients whose allergies are severe enough to seek out an ophthalmologist have already tried this. Most ophthalmologists choose to write a prescription for a prescription drop if theyre treating a patient, Dr. Lindstrom said.

Adding in steroids

For some patients, however, even a prescription combination agent may not be enough. In such cases, Dr. Holland recommends adding a burst of topical steroid. Loteprednol is my favorite because of the safety profile, he said. It doesnt tend to raise IOP like some of the other steroids do, and it is quite effective for patients with allergic conjunctivitis. If an allergic conjunctivitis patient is still symptomatic within 1 or 2 weeks, however, Dr. Holland suggests an oral antihistamine be taken together with the other medications here.

Dr. Lindstrom also finds that for seasonal allergic patients who have reached the point of significant conjunctival edema, a topical steroid is needed. For this he prefers steroids with fewer side effects such as FML (fluorometholone alcohol 0.1%, Allergan) and Lotemax (loteprednol 0.5%, Bausch + Lomb). These drugs penetrate the eye less and are less likely to have the secondary side effects of elevated IOP and cataract if people are using them for an extended period of time, Dr. Lindstrom said, adding that many allergy patients might be using such agents year after year.

For patients with milder allergy who need a slight boost, Alrex (loteprednol etabonate ophthalmic suspension 0.2%, Bausch + Lomb), which is a lower concentration of loteprednol, might be sufficient, he said. Alrex is labeled for allergy, and in the clinical trials and in clinical use it has a very good safety profile, Dr. Lindstrom said. He finds this to be a good in-between drop. However, for more severe cases, he does not consider this. If you have severe chemosis and your lids are swollen shut, then youve got to use a full strength steroid like loteprednol 0.5%, he said. But if youre not well managed with an antihistamine mast cell stabilizer and you need something a little stronger, I find Alrex to be a good drug. In Dr. Hollands view, ophthalmic practitioners do not do enough preventive therapy. If we know that patients have seasonal allergic conjunctivitis and that May is typically a bad month, we often forget what the allergists do and thats to start therapy prior to the patient becoming symptomatic, he said Thats how these medications work best. He tells patients not to wait until they have a full-blown allergic conjunctivitis reaction to begin therapy, pointing out that it takes a lot more medication to shut down a reaction than it does to prevent one from occurring.

The fact is that while antihistamine medication can work quickly, mast cell stabilizers can take a few weeks, Dr. Holland said. You want to start these combination therapies at least 2 to 3 weeks before the trouble period, he said.

Dr. Lindstrom said that for those who have acute allergic conjunctivitis, who may, for example, be allergic to cats, it is likewise a good idea to begin the combination medication before an impending encounter. You want to take the drop before you get exposed and then you wont have a problem because you will have your mast cells stabilized and histamine receptors blockaded, he said.

A few ophthalmologists are starting to do skin testing in their offices, Dr. Lindstrom noted. Weve got a new skin test [Doctors Allergy Formula, Norcross, Ga.] where you prick the skin with around 40 different allergens rather than sending [patients] to an allergist, he said. Practitioners could then educate patients on what to avoid. However, it is the rare ophthalmologist who wants to take the next step, which is allergy desensitization, he said. For more on this test, read Evaluating allergy testing in ophthalmology. For the future, Dr. Holland is eyeing a couple of new options for fighting allergic conjunctivitis. He said there is a higher concentration of olopatadine that has just been approved. It has been available as 0.14% and 0.2%, but theres a recent FDA approval of 0.7%, which looks like it might be the most effective combination medication that will be available, Dr. Holland said. Also, there is currently a clinical trial of topical cyclosporine underway for approval for allergic eye disease, he said. It has been my clinical impression that it has a role in chronic allergic conjunctivitis and hopefully well see some efficacy and approval, Dr. Holland said.

Editors note: Dr. Holland has financial interests with Alcon, Allergan, and Bausch + Lomb. Dr. Lindstrom has financial interests with Alcon and Bausch + Lomb.

Contact information

Holland
: eholland@holprovision.com
Lindstrom: rllindstrom@mneye.com

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Weathering the allergic conjunctivitis Weathering the allergic conjunctivitis
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