We know that in pharmacology, certain medicines, when overused, can stop working because the body will start making less of the receptor for that medicine. For example, this is exactly what happens with the overuse of albuterol for the treatment of asthma. However, I don't know of any science behind why other allergy medicines, such as antihistamines and nasal sprays, stop working.
Recent surveys do show that both adults and children experience the loss of effectiveness of allergy medicines. Nearly 2 out of every 3 adults report that they have stopped an allergy medicine in the past because it stopped working, typically within a matter of months. And, nearly 20% of adults report changing allergy medicines in the past year because the medicine stopped working. Children seem to experience a loss of effectiveness of allergy medicines as well, with nearly 10% changing allergy medicines in the past year, and more than 1 in 4 children needing to change nasal sprays regularly because of the benefit "wearing off."
So, do people actually develop an "immunity" to allergy medicines as a reason why the medicines stop working? It's doubtful, in my opinion. But there's no doubt that people seem to think that the allergy medicine loses its effectiveness, for whatever reason, which results in the need to try something else.
Reasons Why Allergy Medicines Stop Working
Allergy symptoms may change. A medicine that worked for a person’s symptoms before, such as an antihistamine for sneezing or itchy nose, would not be expected to work for nasal congestion. Therefore, it is important to consider the type of allergy symptoms a person is experiencing before choosing an appropriate medication.
Allergy symptoms may worsen. Not everyone is able to control his or her allergy symptoms with a single medicine. Therefore, mild allergy symptoms that were controlled on one medicine might suddenly be uncontrolled if allergy symptoms worsen. I often have my allergy patients use a nasal steroid to control their daily symptoms, and add an oral antihistamine or allergy eye drop for worsening symptoms. Or, if a person takes an oral antihistamine on most days to control itching and sneezing, they might find a benefit in adding an oral decongestant, such as Sudafed, for the occasional day when nasal congestion is more of a problem.
Learn about the best treatments for allergies.
Adult Allergies in America Survey. Accessed May 15, 2011.
Pediatric Allergies in America Survey.
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