The Common Cold Remedy Myth Antihistamines

Antihistamines are popular over-the-counter medications that some people use as cold remedies. Research shows that while antihistamines often relieve symptoms related to allergies, they may be less effective and even detrimental as cold treatments.

How do antihistamines work and when should you take them? Understanding the benefits and risks will guide you in making that decision the next time you’re faced with a runny nose and sneezing due to the common cold.

Understanding Histamines

When an allergic action or infection occurs, the human body produces chemicals called histamines. Histamines are essentially the body’s reaction to the introduction of a foreign substance. Once histamines respond, symptoms tend to appear rapidly and include fits of sneezing and breathing difficulties.

Those who suffer from allergies, such as hay fever, recognize all the familiar allergy symptoms, which include:

  • congestion
  • itching eyes
  • sneezing
  • stuffy and/or runny nose.

The over-production of mucus is the immune system’s attempt to rid the body of the invasion and causes many symptoms related to allergies.

Antihistamines in Action

Antihistamines, as the name implies, work to decrease or eliminate the effects of histamine. Once in the system, they coat the histamine receptors, thus preventing histamines from invading cells and creating annoying and uncomfortable symptoms.

Antihistamines aid in reducing the mucus production associated with allergies. These medicines also provide relief from reactions to poison ivy and insect bites and can help with sinus conditions when they relate to allergies.

As injections applied by a professional, antihistamines are useful in treating anaphylactic shock, which is a severe allergic reaction that can lead quickly to death. The appropriate use of antihistamines also helps prevent allergic reactions for chronic sufferers. The medication works quickly, usually in less than 30 minutes, and can provide protection against exposure to known irritants.

The Effectiveness of Antihistamines for Colds

Many over-the-counter medications for colds contain antihistamines. These may also include decongestants, cough suppressants and pain relievers in varying combinations.

Over-the-counter cold medications often include the first-generation antihistamines, which have a sedating effect. In fact, the main complaint and risk of antihistamine medication is that they have the potential to cause drowsiness. In some individuals, this can be extreme and may interfere with daily tasks to varying degrees.

Other known side effects of sedative-type antihistamines typically include an uncomfortably dry mouth and nose. Other side effects associated with antihistamines include:

  • constipation
  • dizziness
  • ear noise
  • headache
  • heart palpitations
  • stomach pains.

For some individuals, antihistamines have a reverse effect, causing:

  • agitation
  • nervousness
  • restlessness.

Many experts currently recommend eliminating antihistamines from cold treatments due to these negative side effects. Another reason to avoid taking antihistamines for a cold is that a cold is caused by a virus rather than the activity of histamine.

Taking antihistamines can even make it harder for a person with a cold to get well. For example, a runny nose helps eliminate a viral infection from the body. Antihistamines, however, work to impede mucous production.

Studies also show that, in some cases, children can suffer from cold symptoms, such as earaches, longer when they take an antihistamine. They also tend to exhibit signs of over-excitability when taking antihistamines, even for short periods.

Common Antihistamines

It’s important to study labels when purchasing cold remedies. Antihistamines commonly listed include:

  • brompheniramine
  • chlorpheniramine
  • diphenhydramine
  • doxylamine
  • loratadine
  • terfenadine.

Pay close attention to the labels on cold remedies, as it is easy to over-medicate yourself or another if you don’t know all of the contents of a medication.


American Academy of Otolaryngology-Head and Neck Surgery (n.d.). Antihistamines, Decongestants, and “Cold Remedies.” Retrieved November 4, 2007, from the AAO-HNS Web site:

Commoncold, Inc. (1999-2007). Cold Treatments that are Effective and Safe. Retrieved November 4, 2007, from the Common Cold Web site:

The Merck Manuals Online Medical Library (2003). Cold Remedies. Retrieved November 4, 2007, from the Merck Web site: