Making Sense of Over-the-Counter Anti-Allergy Medications

May 03, 2018

As the calendar flips to May, we are all enjoying more daylight, warmer weather, blooming flowers….and oh, no….annoying allergies!

A runny nose, itchy eyes, and stuffiness are a few of the classic allergy symptoms that can irritate us as the season sets in. Several types of over-the-counter medications are available for management of these allergy symptoms and a host of others. This article takes a look at several over-the-counter options, their specific use and actions, and common and potential side effects.

Before you select a medication, it is recommended that you describe your allergy symptoms to your pharmacist, who can then help you select the most optimal anti-allergy medication for relief and explain how to safely take your medicine.

There are numerous products to choose from, and how they are taken varies (i.e. orally, nasal sprays, eye drops). The most optimal agent for you can be best determined by the types of symptoms you are experiencing. You may require one medication or a combination.

Runny nose, itchy or watery eyes, hives, swelling
The recommendation for these symptoms is an oral anti-histamine (i.e. diphenhydramine, cetirizine, desloratadine, or fexofenadine). These agents can cause drowsiness, so take these medicines with caution when you need to drive or do other activities that require alertness.

Why do antihistamines cause drowsiness? Antihistamines prevent the attachment of histamines (which are chemical compounds in your body) to receptors, inhibiting their function. First-generation antihistamines (diphenhydramine and doxylamine succinate) do not differentiate between which histamine receptors they block. They cross the blood-brain barrier and inhibit the histamines role in regulating the sleep and wake cycle, and consequently, this interference in histamine action in the brain causes drowsiness.

Sneezing, itchy or runny nose, sinus congestion, and postnasal drip
For these symptoms, a nasal spray like fluticasone, triamcinolone or azelastine will work best. While effective, these can cause an unpleasant smell or taste, nasal irritation, and nosebleeds.

Itchiness, redness, and swelling of the eyes
If you’re tired of rubbing your eyes, the recommendation is to take eyedrops that include ketotifen. These agents, however, can cause headaches and dry eyes.

Stuffiness and congestion
Recommendation is to take a decongestant {i.e. Sudafed, cetirizine and pseudoephedrine (Zyrtec-D), desloratadine and pseudoephedrine (Clarinex-D), fexofenadine and pseudoephedrine (Allegra-D)}. Side effects of these medications include insomnia, headache, increased blood pressure and irritability. They are not recommended for pregnant women or for people with high blood pressure, cardiovascular disease, glaucoma or hyperthyroidism.

Why do decongestants raise blood pressure? Decongestants have an affinity for alpha-adrenergic receptors in the body and work by constricting arteries in the body (i.e. nasal mucosa, cardiac muscle). While this squeezing results in decreased mucous formation, it also stimulates the alpha receptors on your heart.

The article and included content is to act as an information and education guide for the public, and not intended to substitute individual consultation and direct conversation between the patient and pharmacist. Additional questions and concerned related to selection of anti-allergy medications should be addressed with the pharmacist.

  1. April 17, 2018. Accessed:
  2. DeShazo RD, Kemp SF. Pharmacotherapy of allergic rhinitis. In: Basow DS (Ed). UpToDate [database on the internet]. Waltham (MA): UpToDate; 2012 [cited 2012 Aug 16]. Available from:
  3. Wallace DV, Dykewicz MS, Bernstein DI, Blessing-Moore J, Cox L, Khan DA, et al. The diagnosis and management of rhinitis: An updated practice parameter of the joint task force on practice parameters for allergy and immunology. J Allergy Clin Immunol. 2008;122: S1-S84.
  4. Drug Class Review: Newer Antihistamines: Final Report Update 2 [Internet].