Antihistamines and Decongestants

Email Page

Antihistamines

Antihistamines are among the most commonly used treatments for nasal allergy symptoms. They work by helping to block the action of histamine—one of the chemicals released by the body during an allergic reaction. Histamine dilates the blood vessels of the nose, which in turn causes nasal allergy symptoms. By preventing or blocking the action of histamine, allergy symptoms can be reduced.

Antihistamines are available in liquid, tablet, or nasal spray form, and in both non-prescription (over-the-counter) and prescription formulations.
Antihistamines help to relieve sneezing, runny nose and itchiness of the nose, eyes, ears, and roof of the mouth ; however they are not indicated for reducing nasal congestion.
Some antihistamines may cause drowsiness in people, which, in some cases, could impair mental alertness, or ability to drive or operate machinery. However, there are some antihistamines available that do not cause drowsiness. Other side effects can include dry mouth or nausea.

Decongestants

Decongestants reduce nasal congestion by constricting blood vessels in the lining of the nose. This means less blood is able to flow through the nasal area and less fluid is released into the lining of the nose.

Decongestants are available as prescription and non-prescription medications.
Decongestants help relieve nasal congestion, but they do not relieve other symptoms of nasal allergies, including runny nose, or sneezing.
Some patients using some decongestants may experience side effects including rapid heartbeat, nervousness, increased blood pressure, and sleeplessness. Over-the-counter (OTC) decongestant nasal sprays can cause a "rebound effect," where nasal congestion worsens after you stop using a medication; this can occur when over-the-counter (OTC) decongestant nasal sprays have been used longer than the recommended period.

Antihistamine/decongestant combinations

Some common medications contain both antihistamines and decongestants. Antihistamine/decongestant combinations treat nasal congestion, sneezing, and runny nose.

Antihistamine/decongestants combine the histamine blocking action of antihistamines with the blood vessel constricting action of decongestants.
They are available in both non-prescription and prescription formulations.
Some patients using some of these medications may experience drowsiness, dryness in the mouth, and headache.

Talk With Your Doctor

If you're bothered by nasal allergy symptoms—such as congestion, sneezing, and an itchy or runny nose—ask your doctor about the treatment options available to you. Your doctor knows your medical history and can recommend the most appropriate treatment.