Table of ContentsView AllTable of ContentsDrug ToleranceBronchodilators and CorticosteroidsAntihistaminesWhat to Do
Table of ContentsView All
View All
Table of Contents
Drug Tolerance
Bronchodilators and Corticosteroids
Antihistamines
What to Do
When an allergy medication doesn’t work anymore—either as well as before or at all—it could be because your body is no longer reacting to the drug in the same way it once did or is clearing it too quickly for it to be effective. This is known as a drug tolerance.
This can happen after months and years of use. People who have chronicallergy symptomsare more likely to find that their allergy medicine stops working at some point.
It’s also possible that an allergy medication is no longer working for you because yourallergieshave simply worsened and you need to change yourtreatment plan.
This article discusses how common allergy medications work, why they may stop working over time, what medications are most problematic in this regard, and what to do when you are no longer getting the relief you need.
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Allergy Drug Tolerance
When an allergy medicine stops working, some people think the body has developed a natural defense (immunity) to it. Others may think they have become drug-resistant, as is possible withantibioticsthat no longer work because bacteria has mutated.
Neither of these explanations is correct.
Instead, an allergy medication can stop being effective because the body has developed atoleranceto the drug—especially if it has been overused. This means the body has become more desensitized, or “used to,” to the drug’s effects.
There are two major reasons why drug tolerance happens:
Sometimes, increasing the dose of the drug can make it work again. However, the effect is usually short-lived.And in the case of certain nasal sprays, doing this may actually make congestion worse—a phenomenon known asrebound congestion. (This can also occur if you take a lower dose for too long.)
Is Tolerance the Same as Dependence or Addiction?With certain drugs (particularly psychoactive drugs), tolerance is associated with dependence or addiction. However, this is not the case with allergy medications, since tolerance reduces the efficacy of a drug rather than your need for it.
Is Tolerance the Same as Dependence or Addiction?
With certain drugs (particularly psychoactive drugs), tolerance is associated with dependence or addiction. However, this is not the case with allergy medications, since tolerance reduces the efficacy of a drug rather than your need for it.
If You’re Tolerant of One Allergy Medicine Are You Tolerant to All?
Thankfully, being tolerant of one type of allergy medication doesn’t mean all options for treating your symptoms are off the table. This is because the various classes of drugs that can be part of a treatment plan work in different ways:
Understanding Drug Tolerance
You’re more likely to develop tolerance to some allergy medications than others. For example, the risk of tolerance can be high with beta-agonists.
With this class of inhaled medication, tolerance is dynamic and linked to prolonged use or overuse of long-acting beta-agonists (LABAs) like Serevent (salmeterol).
Tolerance is more likely when the drugs are used on their own. In this case, it can have a “knock-on effect,” inducing tolerance to the short-acting beta-agonists (SABAs) used in rescue inhalers.
This does not seem to happen with anticholinergic inhalants like Spiriva Respimat (tiotropium bromide) or glycopyrronium bromide, for which there is little risk of tolerance.
Dynamic tolerance can also happen with certain corticosteroid formulations, particularly topical ointments, and nasal sprays. Frequent, repeated use can rapidly desensitize the skin and mucosal tissues to the vessel-shrinking (vasoconstrictive) effects of the drugs.
On the other hand, inhaled corticosteroids can significantly reduce the risk of tolerance to beta-agonists when used incombination therapy.
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Researchers are not sure why antihistamines stop working. Most evidence shows that drug tolerance does not happen no matter how long or aggressively the medications are used. If anything, prolonged use tends to reduce a person’s tolerance to the side effects of these drugs (like drowsiness).
There are still many claims that the effects of antihistamines can wane. More often than not, these diminishing effects are related more to the natural course of a person’s allergy than to the drug treatment.
For many people with allergies, a mild hypersensitive reaction can get worse over time, particularly with certainfood allergiesorcross-reactive responsesthat are vulnerable to multiple allergy triggers (allergens).
How To Take Antihistamines
What to Do If Your Allergy Meds Stop Working
If your allergy medications aren’t working anymore, the first step is to call your provider. They can help figure out why this may be the case and recommend what to do next.
Your healthcare provider may recommend one or more of the following:
Certain other health conditions can affect how effective your allergy treatment is as well. With that, your healthcare provider may also:
Using Over-the-Counter Medication for Your Allergy Symptoms
Summary
But there’s another possibility: Often when allergy medicine stops working, the problem is that your allergies or symptoms have gotten worse and you need to change your treatment accordingly.
If you’re no longer getting the symptom control you once did from your allergy medication, speak to your healthcare provider.
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9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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Merck Manual.Tolerance and resistance to drugs.
FHE Health.Drug tolerance vs. dependence and addiction: What are the differences?.
Nardini S, Camiciottoli G, Locicero S, et al.COPD: maximization of bronchodilation.Multidiscip Respir Med.2014;9:50. doi:10.1186/2049-6958-9-50
Nannini LJ, Poole P, Milan SJ, Kesterton A.Combined corticosteroid and long-acting beta2 -agonist in one inhaler versus inhaled corticosteroids alone for chronic obstructive pulmonary disease.Cochrane Database of Systematic Reviews. 2013;2014(6). doi:10.1002/14651858.cd006826.pub2
van den Elzen MT, van Os-Medendorp H, van den Brink I, et al.Effectiveness and safety of antihistamines up to fourfold or higher in treatment of chronic spontaneous urticaria.Clinical and Translational Allergy. 2017;7(1). doi:10.1186/s13601-017-0141-3
American College of Allergy, Asthma, & Immunology.Runny nose, stuffy nose, sneezing.
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