What is the best medicine for nasal allergy? How to take the medicine?
The best medicine depends on the symptoms, the severity and the response to treatment. I always tell my patients that I don’t want the treatment to be worse than the problem. If someone only has mild runny nose once in a while, regular nasal sprays, although potent, may be an overkill.
Generally, I divide treatment into symptomatic treatment and preventive treatment. Symptomatic treatment aim to only treat specific symptoms. They usually work very fast but the effects also wear off quickly once they are stopped if the underlying cause is still present. Such medication do not need to be taken regularly but are taken when patients develop symptoms.
A very common class of medication are known as antihistamines which effectively stop runny nose, itch and sneezing. Many would remember small yellow, blue or pink tablets which family doctors dispense for common cold and cause drowsiness. These are first generation antihistamines which work effectively despite the side effect of making the patient feel very sleepy. Some get used to the sedating effect and can take 4 tablets without feeling drowsy! Second generation antihistamines removed the sleepy side effect and we now even have third generation antihistamines which are more potent because they are the active component of the second generation drugs. Some patients however swear that the old drugs work better and they are right because they had another action which helped dry runny noses. This was via an “anti-cholinergic” effect. It was this effect which caused drowsiness and when scientists removed the drowsy side effect, they removed that drying effect as well. If patients mainly complain of runny nose, sneezing or itch, antihistamines will effectively alleviate symptoms. They can be safely taken long term but if patients are dependent on antihistamines everyday (more than 4 days in a week), they should probably consider using nasal sprays. Similarly, for patients on regular nasal sprays, they may consider taking antihistamines if they have breakthrough symptoms. Lastly, when we try to wean patients off nasal sprays, we can use antihistamines for symptomatic treatment. Once again, if patients need symptomatic treatment very often, they may want to consider other treatment.
While antihistamines are very good for runny nose, itch and sneezing, they don’t work very well for nasal congestion or blockage. In fact, they may make such symptoms worse as they cause drying of mucus which block the nose even more! For blockage, I usually recommend decongestants which are really “synthetic adrenaline”. They cause blood vessels in the nose to constrict, causing engorged nasal turbinates to shrink. Nasal turbinates are swellings at the sides of the nose which contain a lot of blood vessels, which help to warm and humidify the air we breathe in. In infections or allergies, these become engorged, causing blockage. Decongestants can provide very quick relief and can be very useful when suffering from a cold.
Decongestant nose drops can be bought over the counter at most pharmacies and are sold as common cold remedies. They should not be used for chronic problems like allergies as they have a rebound effect. When the effect wears off, if the underlying problem is still present, the vessels dilate and engorge more to try to ‘wash away’ the chemical mediators of inflammation in the nose. Patients feel more blocked than ever and use more and more drops, becoming very dependent on the drops. The long term constriction of blood vessels can also cause permanent damage to the nose. Decongestants can also be found in tablets which do not appear to have a rebound effect. They can however cause the heart rate and blood pressure to go up, especially in the elderly and sometimes cause insomnia when taken late in the day. Decongestants are therefore good for initial control but should not be used for long term control.
For long term control of moderate to severe nasal allergies, nasal steroids are probably the best medication. They stabilise mast cells in the nose and reduce the immune response to allergens. Mast cells release histamine in response to allergy and histamine is what causes runny nose, itch and sneezing. Nasal steroids therefore take time to act, which is why I call them “preventive” medication. The optimum effect may take as long as 1 week of regular use as the histamine previously released will take time to be removed by our bodies. That is also why antihistamines and decongestants are useful in the beginning to help control symptoms. They must also be used regularly, otherwise mast cells will continue to “leak” histamine. They are therefore meant to be used regularly for prolonged periods to be effective. Guidelines suggest using for about 3 months while working on environmental control and allergen avoidance. Some patients can stop nasal sprays without recurrence of symptoms if they achieve good environmental control. If not, long term nasal steroids are very safe because very little is absorbed into our blood stream. US FDA has approved their use even in young children.
Finally, if patients are not keen for long term nasal steroids, there is the option of immunotherapy to desensitise them to what they are allergic to. In the past, this was with injections (popularly known as “allergy shots”) which were given weekly till maintenance dose was reached, followed by monthly maintenance injections for 3 years! Now, there is the option of sublingual immunotherapy, which is basically like medication placed under the tongue. This is done daily and also for 3 years but probably a lot more palatable than injections. There is the promise of potential cure for some patients. It is the costliest treatment and requires patients to be compliant for 3 years, hence it is not the first line treatment but can be considered if patients need long term medication or medication does not adequately control symptoms. For very young patients, many paediatricians are also recommending immunotherapy to prevent allergy from “marching” on – avoiding all the other manifestations of allergies like asthma and atopic dermatitis.