Doctor, Please Explain

Antihistamines, Decongestants, and “Cold” Remedies

Insight into recommended use and side effects

• What are the side effects of antihistamines?

•  Who should not use decongestants? 

• What are combination remedies?  and more…

Drugs for stuffy nose, sinus trouble, congestion and drainage, and the common cold constitute a large segment of the over-the-counter market for America’s pharmaceutical industry. Even though they do not cure allergies, sinusitis, colds, or the flu, they provide welcome relief for at least some of the discomforts of seasonal allergies and upper respiratory infections. However, it’s essential for consumers to read the ingredient labels, evaluate their symptoms, and choose the most appropriate remedy.

What are antihistamines?

Histamine is an important body chemical that is responsible for the congestion, sneezing, and runny nose and itching that a patient suffers with an allergic attack or an infection. Antihistamine drugs block the action of histamine, therefore reducing these symptoms. For the best result, antihistamines should be taken before allergic symptoms get well established, but they can also be very effective if taken after the onset of symptoms.

What are the side effects of antihistamines?

Most of the older over-the-counter antihistamines produce drowsiness, and are therefore not recommended for anyone who may be driving an automobile or operating equipment that could be dangerous. The first few doses cause the most sleepiness; subsequent doses are usually less troublesome. Some of the newer over-the-counter and prescription antihistamines do not produce drowsiness.

Typical antihistamines include Benadryl®*, Chlor-Trimetron®*, Claritin®, Dimetane®*, Hismanal®, Nolahist®*, PBZ®*, Polaramine®, Seldane®, Tavist®*, Teldrin®, Zyrtec®, Allegra®, and Allavert®.

What are decongestants?

Congestion in the nose, sinuses, and chest is due to swollen, expanded, or dilated blood vessels in the membranes of the nose and air passages. These membranes, with a great capacity for expansion, have an abundant supply of blood vessels. Once the membranes swell, one becomes congested.

Decongestants help to shrink the blood vessels in the nasal membranes and allow the air passages to open up. Decongestants are chemically related to adrenaline, the natural decongestant, which is also a type of stimulant. Therefore, the side effect of decongestants taken as a pill or liquid is a jittery or nervous feeling causing difficulty in going to sleep and elevating blood pressure and pulse rate.

Who should not use decongestants?

Decongestants should not be used by a patient who has an irregular heart rhythm, high blood pressure, heart disease, or glaucoma. Some patients taking decongestants experience difficulty with urination. Furthermore, decongestants are often used as ingredients in diet pills. To avoid excessively stimulating effects, patients taking diet pills should not take decongestants.

Typical decongestants in pill or liquid form are Dura-Vent®, Exgest®, Entex®, Propagest®, Novafed®*, and Sudafed®*.

* May be available over the counter without a prescription. Read labels carefully, and use only as directed.

Decongestants are also available over the counter in nasal spray form. This method of medication delivery brings immediate relief to the nasal mucous membranes without the usual side effects that accompany pills or liquids that are swallowed. Over-the-counter decongestant nose sprays should be reserved for urgent, emergency and short term use. Because repetitive use can lead to lack of effectiveness and return of the congestion, and thus lead to the urge to use more sprays more frequently, these medications often carry a warning label, “Do not use this product for more than three days.” This problem will only improve once the use of the nasal drops or spray is discontinued.

What are combination remedies?

Theoretically, if the side effects could be properly balanced, the sleepiness caused by antihistamines could be cancelled by the stimulation of decongestants. For instance, one might take the antihistamine only at night and take the decongestant alone in the daytime. Alternatively, one could take them together, increasing the dosage of antihistamine at night (while decreasing the decongestant dose) and then doing the opposite for daytime use. Since no one reacts exactly the same as another to drug side effects, a consumer may wish to adjust the time of day the medications are taken until finding the combination that works best.

Antihistamines/decongestants: Many pharmaceutical companies have combined antihistamines and decongestants together in one pill.

Typical combinations of antihistamines with decongestants are: Actifed®*, A.R.M.®*, Chlor-Trimeton D®*, Claritin D®, Contac®*, CoPyronil 2®*, Deconamine®, Demazin®*, Dimetapp®*, Drixoral®*, Isoclor®*, Nolamine®, Novafed A®, Ornade®, Sudafed Plus®, Tavist D®*, Triaminic®*, and Trinalin®.

What should I look for in a “cold” remedy?

Decongestants and/or antihistamines are the principal ingredients in “cold” remedies, but drying agents, aspirin (or aspirin substitutes), and cough suppressants may also be added. Therefore, consumers should choose remedies with ingredients best suited to combat their own symptoms. If the label does not clearly state the ingredients and their functions, the consumer should ask the pharmacist to explain them. 

Which medicine do I need?

The chart below makes it simple for you to determine which type of medicine is right for you based on the symptoms that each treats.