Seasonal allergies can drive patients mad. Once the weather warms up, trees, grasses and flowers bloom, and air-borne pollen grains are dispersed everywhere. Once inhaled by susceptible people, the pollens can set off an allergic chain reaction, causing annoying – even debilitating – symptoms.
Welcome to summertime in Canada.
Sayanth Sahathevan, 22, is one such allergy-sufferer. "I have a runny nose all the time," he says. "My eyes water and burn, my throat itches and you should hear me sneeze." An early-childhood educator who works with five-year-olds, he is embarrassed by his allergies at work. "My kids look at me when I sneeze … it scares them." Even his sleep is disturbed, as his sneezing often wakes him.
Fortunately for such patients, two new pills have been released in Canada. Both drugs are "immunotherapies" – they are as strong as allergy-needle vaccinations. They treat the cause, not just the symptoms (which is what over-the-counter antihistamines do). Grastek, the first drug, immunizes against grass allergy; the second drug, Ragwitek, against ragweed. Most remarkably, both these novel medications are once-daily tablets, which dissolve in seconds under the tongue.
Till now, most immunizations, including those for allergies, have been injections. Patients would have to go to a health-care practitioner to receive weekly needles. Though this type of treatment has been around for about a century, it can be challenging and bothersome for patients to maintain regularly. But these novel tablets offer some patients a way out from weekly clinic visits.
Once patients pass the first test dose in their doctor's office, to ensure they don't have a full-body reaction, they can self-administer these new sublingual tablets at home. (About 5 out of 1000 patients taking immunotherapy experience reactions requiring medical attention.)
Dr. Amarjit Cheema, an allergy specialist and lecturer practising in Mississauga since 1988, values these pill options. "Now with these newer forms of immunotherapy," he says, "we can start these treatments earlier." A prolific researcher who has conducted more than 100 research trials, Cheema has seen his patients benefit. "You get a good response right after the first month of treatment." He notes that Grastek "is effective in children and adults," but Ragwitek is currently recommended for patients 18 years and over.
One of the collateral benefits of immune treatment is that other allergy-driven conditions benefit. Think you have had a cold for a month? It's much more likely to be sinus congestion due to allergies. Always have a tickle and have to clear your throat? You may have post-nasal drip, just like a leaky faucet.
These conditions are all cousins. As I explain to patients, "If you have allergy in the skin, we call that eczema; allergy in the chest, we call that asthma; and allergy in the nose, that's rhinitis and/or sinusitis." These seemingly separate problems are actually part of the extended allergy family.
So treating the underlying allergy with immunotherapy helps soothe the whole allergy network, reducing the varied symptoms. Think of the ear, nose, throat and sinuses as a "united airway." (In lectures, I even show slides of the airline to make the point.)
As with other forms of immune treatment, it's important to prime the system before the season begins. In Canada, roughly speaking, grass-allergy season runs from May 15 to July 15; ragweed season, from Aug. 15 to Oct. 15. "It's important to know the dates," notes Cheema, "so we can begin the treatment before the allergy season."
How do you find out which pollens are causing your symptoms? For patients with high-end allergies that are not controlled with first-line medications such as the antihistamines and nasal steroid sprays, Cheema recommends allergy skin tests. "That's the best way to determine which pollens are provoking allergy."
Patients should start taking Grastek or Ragwitek tablets at least two months before the grass or ragweed season (a March start for grass; a June start for ragweed). The usual recommendation is that patients continue taking the tablets for five to six months.
If you miss the preseason window and try to take the pills in-season, you'll likely double your trouble, having to deal with the drug's side effects in addition to regular outside exposure.
The pills contain concentrated forms of pollen. For example, Grastek contains purified Timothy grass pollen. The goal, as with all needle vaccinations, is to give the body a preliminary taste of the offending particles. This primes the immune system to produce police molecules, the immunoglobulin proteins, that sweep up pollen and prevent the cascade of allergy symptoms before they start.
The pills are not without side effects. About 30 per cent of patients will experience significant mouth and ear itching, a local reaction to the concentrated pollens. But these early side effects fade with time. Cheema notes that with proper use, patients' allergy symptom scores go down "about 30 per cent."
While these are not cures, this new generation of drugs may offer significant relief to the 20 per cent of Canadians who suffer from seasonal allergies.