Call Us: 479-242-4220

Antihistamines, Decongestants, & “Cold” Remedies

Drugs for stuffy nose, sinus trouble, congestion and the common “cold” constitute the largest segment of the over-the-counter market for America’s pharmaceutical industry. When used wisely, they provide welcome relief for at least some of the discomforts that affect almost everyone at one time or another and that affect many people chronically.

Drugs in these categories are useful for relief of symptoms from allergies, upper respiratory infections (i.e., sinusitis, “colds,” flu) and vasomotor rhinitis (a chronic stuffy nose caused by such unrelated conditions as emotional stress, thyroid disease, pregnancy and others). These drugs do not cure the allergies, infections, etc.; they only relieve the symptoms, thereby making the patient more comfortable.


Histamine is an important body chemical that is responsible for the congestion, sneezing and runny nose that a patient suffers with an allergic attack or an infection. Antihistamine drugs block the action of histamine, therefore reducing the allergy symptoms. For the best result, antihistamines should be taken before allergic symptoms get well established.

The most annoying side effect that antihistamines produce is drowsiness which is less common with non-sedating antihistamines.  That may be desirable when taken at bedtime, but it is a nuisance to many people who need to use antihistamines in the daytime. To some people, it is even hazardous. These drugs are not recommended for daytime use for people 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.

Typical non-sedating antihistamines include Claritin®, Allegra®, Zyrtec®

Typical sedating antihistamines includeBenadryl®, Chlor-Trimeton®*, Dimetane®*, Hismanal®, Nolahist®*, PBZ®, Polaromine®,  Tavist®, and Teldrin®*.


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 have an abundant supply of blood vessels with a great capacity for expansion (swelling and congestion). Histamine stimulates these blood vessels to expand as described previously.

Decongestants, on the other hand, cause constriction or tightening of the blood vessels in those membranes, which then forces much of the blood out of the membranes so that they shrink and the air passages open up again.

Decongestants are chemically related to adrenaline, the natural decongestant, which is also a type of stimulant. Therefore, the side effect of decongestants is a jittery or nervous feeling. They can cause difficulty in going to sleep, and they can elevate blood pressure and pulse rate. Decongestants should not be used by a patient who has an irregular head rhythm (pulse), high blood pressure or heart disease. They also should not be used by a patient who has glaucoma. Some patients taking decongestants experience difficulty with urination. Furthermore, decongestants are often used as ingredients in diet pills. Therefore to avoid excessively stimulating effects, patients taking such diet pills should not take decongestants also, and vice versa.

Typical decongestants are phenylephrine (NeoSynephrine®*), phenylpropanolamine (Entex®*, Propagest®), and pseudoephedrine (Novafed®*, Sudafed®*).

Combination Remedies

Theoretically, if the side effects could be properly balanced, the sleepiness caused by antihistamines could be cancelled by the stimulation of decongestants. Therefore, numerous combinations of antihistamines with decongestants are available: Actifed®*, A.R.M.®*, Chlor-Trimeton D®*, Contac®*, CoPyronil 2®*, Deconamine®, Demazin®*, Dimetapp®*, Drixoral®*, lsoclor®*, Nolamine®, Novafed A®, Ornade®, Sudafed Plus®, Tavist D®, Triaminic®*, Trinalin®, just to name a few.

A patient may find one preparation quite helpful for several months or years; Then he may need to switch to another one later when the first loses its effectiveness.

Since no one reacts exactly the same as another to the side effects of these drugs, a patient may wish to try his own ideas on adjusting the dosages. For example, he might take the antihistamine only at night and take the decongestant alone in the daytime. Or he might take them together, increasing the dosage of antihistamine at night (while decreasing the decongestant dose) and then doing quite the opposite for daytime use. For example:

Antihistamine (Chlor-Trimeton®, 4 mg) – one tablet three times daily and two tablets at bedtime.


Decongestant (Sudafed®, 30 mg) – two tablets three times daily and one tablet at bedtime.






Runny Nose

Stuffy Nose

Itchy Eyes



Dry Mouth & Nose


Stuffy Nose




Rapid Heart Beat

Combinations of above

All of above

Any of above (more or less

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

“Cold” Remedies

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. The patient should choose the remedy with ingredients best suited to combat his own symptoms. If the label on the medicine bottle does not dearly state the ingredients and their functions, the consumer should ask the pharmacist to explain them.

Nose Sprays

The types at nose sprays that can be purchased without a prescription usually contain decongestants for direct application to nasal membranes. They can give prompt relief from congestion by constricting blood vessels, as described previously under “Decongestants.” However, direct application creates a much stronger stimulation than a decongestant taken by mouth, and it impairs the circulation in the nose somewhat which, after a few hours, stimulates the vessels to dilate or expand to improve the blood flow again. This results in a “rebound” or “bounce-back” effect. The congestion recurs. Then the patient feels he needs to use the spray again, and if he does so, it starts the cycle again. Spray-decongestion-rebound and more congestion. More spray, etc.

In infants, this rebound rhinitis can develop in two days or so, whereas in adults it often takes several more days to become established. An infant taken off the drops for 12 to 24 hours is cured; but well.established cases in adults often require more than a simple “cold turkey” withdrawal. They need decongestants by mouth, sometimes corticosteroids, and sometimes (in patients who have used the sprays for months and years continuously) a surgical procedure to the inside of the nose. For this reason, the labels on these types of nose sprays contain this warning: “Do not use this product for more than three days.”

Nose sprays should be reserved for emergency and short-term use.

(The above description and advice does not apply to the type of anti-allergy nose sprays that may be ordered by your physician and which are available by prescription only.)

Take the first step towards a healthier lifestyle. Make an appointment at  Arkansas Center for Ear, Nose, Throat and Allergy for an evaluation today.


©1993. American Academy of Otolaryngology-Head and Neck Surgery, Inc. This leaflet’s published as a public service. The material may be freely used so long as attribution is given to the American Academy of Otolaryngology-Head and Neck Surgery, Inc., Alexandria, VA.