Asthma and Allergies

Premier Health providers answer frequently asked questions on asthma and allergies.

How do allergy medications work?

Dr. Alappatt discusses how allergy medications work. Click play to watch the video or read the transcript.


Different types of allergy medications work in different ways, but many work by blocking the chemicals that cause allergy symptoms, according to the National Institutes of HealthOff Site Icon (NIH).

The NIH states the following medications work in the following ways:

  • Allergy shots – Also known as subcutaneous immunotherapy (SCIT), these have been used for more than 100 years to give people long-lasting relief. They work by using a series of shots to build up a resistance to the allergen and then to maintain that resistance.
  • Antihistamines – These can be taken by mouth or in a nasal spray. They help to reduce itchy eyes and nose, runny nose, sneezing, and nasal stuffiness.
  • Cromolyn sodium – This is a nasal spray that helps to block chemicals that cause allergy symptoms, which include histamine and leukotrienes.
  • Decongestants – These can be taken by mouth or as a nasal spray. They help shrink the lining within the nasal passages, which helps to reduce nasal stuffiness. These are to be used for short-term help, and can cause more problems with ongoing use.
  • Leukotriene receptor antagonists – The prescription medication montelukast is an example of these. They block chemical messengers (not including histamine) that lead to allergic reactions.
  • Nasal corticosteroids – These sprays help block allergic reactions. They contain anti-inflammatory medicines and are often thought to be the most effective medication for allergic rhinitis and nasal congestion.
  • Sublingual immunotherapy – There are three types of these under-the-tongue tablets used to treat grass and ragweed allergies with sublingual immunotherapy (SLIT). These can be used as an alternative to allergy shots.

For more information about how allergy medications work, talk with your doctor.

Learn more:

Source: Anessa Alappatt, MD, Fairborn Medical Center; J. Douglas Aldstadt, MD, Family Physicians of Englewood; Joseph Allen, MD, Family Medicine of Vandalia; Michael Chunn, MD, Michael A. Chunn, MD, Family Practice; Chandan Gupta, MD, Monroe Medical Center; Joseph Leithold, MD, Woodcroft Family Practice; Anne Reitz, MD, Centerville Family Medicine; Grenetta Ritenour, CNP, Jamestown Family Medicine; Melinda Ruff, MD, Centerville Family Medicine; Marcus Washington, MD, Premier Health Family Medicine; Mark Williams, MD, Beavercreek Family Medicine