Here’s Why Your Allergy Medicine Has Stopped Working

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Benita Lee
Benita Lee, MPH, is on the Research Team at GoodRx.
Posted on

Have you noticed that your allergy medicines don’t work as well as they used to? You’re not alone. According to a national survey, 37% of allergy sufferers change their nasal allergy medicine at least once every few years because they’re not effective enough.

Reviews of allergy medicines on Iodine.com support this phenomenon. Someone who recently reviewed Flonase Allergy Relief, for example, said it “stopped working after a year or so of use.”

Another reviewer who had used Zyrtec-D, a popular over-the-counter antihistamine, reported that the “drug worked for [her] when [she] first started taking it, and so [she] continued to do so on a regular basis for year-round allergies. A few years in, [she] noticed it was growing less effective.” She eventually stopped taking the medicine because skipping doses caused unbearable itching.


Do people build up resistance to allergy medicines?

Developing a resistance to decongestants or antihistamines is pretty uncommon. Inhaled steroids like Flonase and Nasacort are often first-line treatments for chronic nasal congestion and runny nose. Both are available without a prescription and do not lead to resistance.

However, Afrin, an over-the-counter nasal decongestant spray can make congestion worse with long-term use. Afrin (oxymetazoline) is a non-steroidal drug that can cause rebound congestion, or swelling of the nasal linings after three or four days of use unrelated to the original sinus infection or allergic reaction.

Antihistamines are another popular choice for treating allergies. Fortunately, studies have shown that people do not build up resistance to these drugs.

So, why do allergy medicines stop working?

Allergy medicines can stop working for many reasons. Here are some examples:

1) Changes in the environment

Air pollution and warm temperatures can worsen your allergy symptoms, so much so that allergy medicines seem to stop working. Both of these culprits appear in the spring and summer, which is why allergy season usually begins as temperatures start warming up after winter. To add insult to injury, chlorinated swimming pools, a hallmark of summer, can also cause your allergies to act up.

We’re also getting longer and longer pollen seasons each year. Warmer days and high levels of pollution in the air can cause trees to create pollen for longer periods of time. To better prepare for summer days outside, check out this allergy tracker here

2) New allergies

Just because you’ve been able to manage your allergy symptoms for years, that doesn’t mean you’re in the clear. Acquiring new allergies as you get older is not uncommon, and the medicines that worked for your previous allergies may not work as effectively for your new allergy symptoms.

3) Not taking medicines as prescribed

If your allergy symptoms have stopped bothering you, you may be tempted to stop taking your medicines. Don’t. Many allergy medicines need to be taken daily to keep symptoms under control. In fact, the best way to prevent symptoms is to have the medicine already in your system, so that when allergens come your way, your immune defenses know not to overreact.

4) Age and stress

Age and stress can both increase your sensitivity to allergens and kick your allergic response into high gear, especially as you’re exposed to the same allergens year after year. As a result, medicines that worked when you were younger or less stressed may not be strong enough to curb your symptoms now.

– – –

If you’ve stuck to your allergy medicine schedule, reduced your exposure to allergens, and tried to reduce your stress levels, and you’re still suffering from allergy symptoms, it might be time to see an allergy specialist. They’ll be able to help you assess any new allergen sensitivities and give you advice on what steps to take next.

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