Antihistamines or Decongestants: Which Allergy Relief Do You Need?

Antihistamines or Decongestants: Which Allergy Relief Do You Need? Feature Image
October 22, 2020

What Are Antihistamines?

Antihistamines are medicines used to relieve allergy symptoms, such as hay fever, hives, conjunctivitis, and reactions to insect bites or stings. Antihistamines target histamine, which your body makes during an allergic reaction. They come in the form of pills, nasal sprays, body sprays, and eye drops used daily. 

Antihistamine pills target itching, sneezing, and runny nose. Body sprays are also used to relieve itching on the skin. The nasal sprays relieve congestion, an itchy or runny nose, and postnasal drip while eye drops soothe itchy and watery eyes. While these antihistamines are effective in treating various symptoms, they do not work right away. They work best when taken before you feel a reaction. Ask our allergy specialists which form of antihistamine is best for your symptoms.

Side Effects of Antihistamines

Side effects differ with each product. However, the main side effects of antihistamines include:

  • Drowsiness
  • Dry mouth
  • Dry eyes
  • Blurred or double vision
  • Dizziness and headache
  • Low blood pressure

It’s important to disclose all health problems to your doctor or allergist so they can determine if you are at risk of experiencing side effects from antihistamines or decongestants.

What Are Decongestants?

Decongestants are medicines that relieve congestion by reducing swelling, inflammation, and mucus formation within the nasal passages or the eye. They are not effective in treating other allergy symptoms such as runny nose or sneezing. Decongestants come in the form of nose drops or nasal sprays, eye drops, and as tablets, capsules, and syrup. 

You should not use the nasal sprays for an extended period of time as they can make your symptoms harder to treat. Doctors recommend using them for no more than 3 days at a time to relieve congestion. Decongestants only provide short-term relief from congestion and do not cure the underlying cause or condition. 

They are also used for other conditions associated with nasal or eye congestion such as a cold or sinusitis. Your allergist will determine the proper decongestant for your condition.

Side Effects of Decongestants

Many risks of side effects when using decongestants are unknown. They may include:

  • Rebound congestion
  • Elevated blood pressure
  • Urinary problems
  • Insomnia
  • Irritability

In some patients, even a small dosage will cause side effects. That’s why it’s important to schedule a one-on-one consultation with a board-certified allergist to discuss your health history. They will determine which antihistamines or decongestants are best for you. Our allergists will create a personalized treatment plan to treat your allergy or sinus symptoms.

Other Allergy Relief Medications

Along with antihistamines and decongestants, there are nasal steroids and allergy immunotherapy that provide allergy relief. Nasal steroids relieve congestion, a runny or itchy nose, sneezing, and other allergic rhinitis symptoms. These are prescribed by our allergists and are very effective in soothing allergy symptoms. 


Allergy immunotherapy is shots or tablets used to build a tolerance to certain allergens reducing the need for daily medications. They are approved for pollen, insect stings, environmental, and peanut allergies. This treatment begins as weekly shots and is carried on for two to five years. However, many patients notice an improvement in allergy symptoms within six months of starting immunotherapy. For more information on allergy immunotherapy, call NY Allergy & Sinus Centers at (212) 686-6321 to schedule an appointment with our top-rated allergists.