The most popular types of over-the-counter (OTC) allergy medications are:

  • Antihistamines
  • Decongestants
  • Nasal steroid sprays

Read on to learn more about each of these, including how they work and what they do.

Antihistamines 

During an allergic reaction, your immune system releases histamines. These compounds can cause physical reactions such as itching, swelling, and redness. Antihistamines block histamines to prevent these symptoms.

Antihistamines can help with sneezing, congestion, and itching.

OTC histamines are typically categorized by generation. 

First generation

First-generation antihistamines, known for causing drowsiness in some people, include:

  • Chlorpheniramine (Chlor-Trimeton and Allerest)
  • Diphenhydramine (Benadryl, Banophen, and ZzzQuil)

Second and third generation

Second- and third-generation antihistamines typically don’t cause drowsiness to the same degree as first-generation antihistamines. They also require fewer doses. They include:

  • Cetirizine (Zyrtec)
  • Fexofenadine (Allegra)
  • Levocetirizine (Xyzal)
  • Loratadine (Claritin, Alavert)

Decongestants 

When the tissues in your nose come in contact with an allergen, they may react by swelling. This swelling can result in mucous production. The blood vessels in your eyes can also swell, making them red.

Decongestants typically bring quick, temporary relief for sinus and nasal congestion by shrinking blood vessels and nasal tissues. OTC decongestants include:

  • Pseudoephedrine (Sudafed, Afrinol)
  • Phenylephrine hydrochloride (Neo-Synephrine)
  • Oxymetazoline (Afrin)

Nasal decongestant sprays like Afrin and Neo-Synephrine should only be taken for a maximum of 3 days to avoid rebound congestion. If symptoms persist after 3 days, talk to your pharmacist or doctor.

Nasal steroid sprays

By reducing inflammation associated with allergies, nasal steroid sprays can treat and prevent runny nose, sneezing, and nasal stuffiness and itch. OTC nasal steroid sprays include:

  • Fluticasone (Flonase)
  • Budesonide (Rhinocort)
  • Triamcinolone (Nasacort)

Nasal steroids typically take a few weeks to work, so they’re not for short-term relief.

Allergy medication side effects 

Because each type of OTC allergy medication has potential side effects, talk to your doctor or pharmacist before selecting one to relieve your allergy symptoms. 

Side effects for older (first-generation) antihistamines include:

  • Dizziness and blurry vision
  • Drowsiness
  • Dry mouth, nose, and throat
  • Upset stomach
  • Constipation
  • Decreased tear production
  • Difficulty urinating

For newer (second- and third-generation) antihistamines, side effects include:

  • Drowsiness
  • Dry mouth
  • Dry eyes
  • Stomach problems

Possible decongestant side effects include:

  • Temporary nasal burning, stinging, running, or dryness
  • Sneezing
  • Dizziness and headache
  • Nervousness
  • Increased heart rate or blood pressure
  • Loss of appetite
  • Sleep problems and irritability

For corticosteroids, side effects may be:

  • Headache
  • Nasal dryness or irritation
  • Nosebleed
  • Throat irritation
  • Cough
  • Nausea
  • Vomiting

How do I choose an OTC allergy medication? 

When choosing an OTC allergy medication, talk to your pharmacist. They can help you choose what is best for you.

Read warning labels to review potential side effects. For example, according to the Mayo Clinic, you should generally avoid nasal decongestants if you have:

  • High blood pressure
  • Diabetes
  • Ischemic heart problems
  • Glaucoma
  • Benign prostatic hyperplasia, or BPH
  • Thyroid disorders
  • Seizures

 Harvard Medical School suggests that trial and error may be the best way to find the medications that best relieve your symptoms.

If, after a month of trying out OTC remedies, you still have symptoms, talk to your doctor. They may recommend an allergist or an ear, nose, and throat (ENT) specialist. Or they may suggest exploring other options, such as prescription medications and allergy shots.

Takeaway 

If you’re considering an OTC medication to relieve your allergy symptoms, discuss your choices and the potential side effects with your pharmacist. They can help you find the best choice based on your symptoms, current health, and the other medications you may be taking.

If, after exploring OTC antihistamines, decongestants, and nasal steroid sprays, you’re not getting enough relief, check with your doctor. They may suggest prescription medication or a visit to a specialist.