General Principles

Cold treatments recommended in have been properly tested and found to be effective. Their side effects are known and are acceptable for treating a mild illness like a cold. They include the following:

  • Older antihistamines ("first generation")
  • Nonsteroidal antinflammatory drugs (NSAIDs)
  • Decongestants (vasoconstrictors)
  • Cough suppressants (narcotics)
  • Anticholinergics (ipratropium)

A common cold is a two step process (see How Cold Virus Infection Occurs and What Causes Cold Symptoms). The first step is virus infection of nasal cells. The second step is the activation of the inflammatory mediators which directly cause the cold symptoms. Ideally, it is desirable to treat both parts of the process but currently drugs for treating the virus infection (antivirals) are not commercially available.

Selecting Cold Treatments Based on Testing Status

Cold treatments can be placed into 3 categories:

  1. Adequately tested and found to be effective and safe (seeĀ Testing Cold Treatments)
  2. Adequately tested and found not to be effective and/or safe
  3. Have not had adequate testing to determine if effective and safe

Using a cold treatment which has received proper testing and is known to be effective and safe has the following advantages:

  • The treatment will likely work for you.
  • Most of the treatment's side effect are likely to be known.
  • You will receive honest value.

Using a cold "treatment" based on an idea that has not had adequate testing has the following disadvantages:

  • The supposed "treatment" may not work because the idea on which it is based is wrong.
  • The "treatment" may harm you because of unknown side effects.
  • Using an untested "treatment" which is ineffective keeps you from using a proven treatment that does work.
  • You may not receive honest value.

Effective and Safe Treatments

Histamine is a natural substance, one of the important inflammatory mediators produced in certain cells in the body. (20)

When introduced into the nose, histamine causes dilatation and leakage of blood vessels. (20) Histamine is also a powerful stimulant of the sneeze reflex. These effects of histamine cause sneezing, coughing, runny nose, and stopped up nose during colds. Histamine may also have a role in causing coughs, but this is less certain.


There are two classes of antihistamines, the older ("first generation", "sedating") and the newer ("second generation", "non-sedating") classes. (20) The older class of antihistamines is effective for treating colds.

Antihistamines work by preventing histamine from attaching to a cellular receptor, H1. Attachment to this receptor is necessary for histamine activity to occur. (20) The first generation antihistamines also block the activity of a part of the nervous system, the parasympathetic system, that stimulates mucus glands secretion.

Early studies of the first generation antihistamines for the treatment of colds gave negative results because of inadequate precision in recording of cold symptoms. The results of these studies are now known to be incorrect.

Later studies of first generation antihistamines for treatment of colds employed careful recording of individual cold symptoms on a day-by-day basis. (21-23) These studies showed that first generation antihistamines are quite effective in reducing the sneezing and runny nose of colds. Measured nasal weights were also reduced. One of the antihistamines tested, brompheniramine, reduced the frequency and severity of cough. (23)

The major side effect of first generation antihistamines is drowsiness, which may be severe in some people. (20) Alcohol, sedatives, and tranquilizers increase the drowsiness associated with first generation antihistamines. Also, these antihistamines may cause difficulty in urination in men who have enlargement of the prostate gland and make glaucoma worse in people who have this eye problem.

Antihistamines shown to be effective in double blind, randomized, controlled clinical trials include brompheniramine, chlorpheniramine, and clemastine. (21-23) Other first generation antihistamines have received various degrees of testing for treatment of the common cold. The duration of activity varies among the different first generation antihistamines, and sustained-release preparations are available for some.

The newer (non-sedating) antihistamines do not appear to have the same degree of effectiveness for treating the sneezing and nasal discharge of colds. (24)

Nonsteroidal Antiinflammatory Drugs (NSAIDs)

Nonsteroidal antiinflammatory drugs, such as ibuprofen and naproxen, are effective in treating inflammation, pain, and fever. (25) A major action of NSAIDs is to block the production of certain natural inflammatory mediators called "prostaglandins."

NSAIDs have been used in medical practice to treat general symptoms of a cold such as feverishness, chilliness, muscle ache, and not feeling well in general. (25) Also there has been interest in the use of NSAIDs to treat other cold symptoms, especially cough. (26-28) However, only a few clinical trials have been published on the use of NSAIDs for treating colds.(28-30)

The major side effect of NSAIDs is irritation of the gastrointestinal tract. (25) In some people, this can lead to gastrointestinal ulceration and bleeding. NSAIDs may also prolong bleeding and reduce kidney function.


Decongestants, such as pseudoephedrine, are in the category of "alpha-adrenergic agonists." (31) These drugs open the nasal passages by shrinking blood vessels in the mucus membrane of the nose, which is the primary cause of the nasal obstruction of colds.

Decongestants may be taken by mouth or applied directly on the nasal mucus membrane in the form of nose drops and sprays. (31)

Decongestant nose drops and sprays have rapid and powerful action in relieving nasal obstruction. (31) When the decongestant effect of the drug wears off, nasal obstruction rapidly returns. Nasal decongestants also burn and irritate the throat.

Decongestants taken by mouth have less powerful and immediate activity but cause less problem with the cycles of recurrent nasal obstruction than topical preparations. (31)

Oral decongestants may produce rapid heart rate, blood pressure elevation, and nervous stimulation. (31) However, when taken in recommended doses, oral decongestants have been shown to be safe, even in patients with hypertension controlled on treatment. (32) When applied directly to the mucus membrane of the nose, decongestants tend to lose their effectiveness over time and result in "rebound" obstruction and mucosal damage. (31)


Anticholinergics are a class of drugs that block the action of the parasympathetic nervous system on mucus gland secretion, thereby reducing nasal discharge. (33) In this, they have similar activity to first generation antihistamines.

Anticholinergics differ from antihistamines in not having activity against histamine. Because of this, they are less effective in treating sneezing. (33)

Anticholinergic nasal sprays were found to reduce nasal discharge and measured nasal mucus weights in patients with colds. (34-36)

Anticholinergics may cause difficulty in urination in men with prostate disease and worsen the eye problem of glaucoma. (33)

Cough Suppressants

Cough suppressants are natural narcotics, like codeine, and synthetic narcotics, like dextromethorphan (DM). (37)

Cough suppressants act on the brain to depress the cough reflex center. (37) Their effectiveness in patients with chronic cough has been demonstrated in controlled trials but there is little published information on their effectiveness in coughs associated with colds. (38)

Cough suppressants can produce gastrointestinal discomfort but otherwise have few side effects. (37)

Cough suppressants should not be used in patients with lung diseases where cough may be ineffective and secretions retained in the lung.

In normal healthy people with good cough reflexes, cough suppressants are safe.

Cold Treatment for Adults

Combination Cold Products

Many combination cold products containing various mixtures of antihistamines, NSAIDs, decongestants, and cough suppressants are commercially available. (39)

Many of the currently available combination cold products have not been tested in clinical trials to determine the degree of their effectiveness.

Also, there is little information available from head-to-head comparisons of these products.

The effectiveness of first generation antihistamines for sneezing, runny nose, and possibly cough has been impressive in recent clinical trials. (21-23) NSAIDs are effective for general cold symptoms such as feverishness, headache, and not feeling well and may be of benefit for controlling coughs. (26-28) A first generation antihistamine taken with an NSAID provides a sound basis for an initial cold treatment that will give relief of most cold


Begin treatment at the earliest sign of a cold

Take a sustained-release first generation antihistamine such as chlorpheniramine, brompheniramine, or clemastine.

Also, at the same time, take a nonsteroidal antiinflammatory drug (NSAID) such as ibuprofen or naproxen.

Continue with the antihistamine and NSAID treatment every 12 hours until cold symptoms clear (3-7 days).

Add an oral decongestant such as pseudoephedrine and a cough suppressant such as dextromethorphan if the antihistamine-NSAIDs treatment does not control nasal obstruction and cough.

If nasal symptoms, facial pressure, and cough are no better or worse after 7-10 days, consider contacting your physician to treat bacterial complications if necessary (see Complications of Colds).

Importance of Early Treatment

The best strategy for treating a cold is to start treatment as soon as there is the recognition that a cold is beginning and to continue treatment on a regular basis until it appears that the cold is over (3-7 days).

The rationale for early continuous cold treatment is based on 1) the known time course of uncomplicated and untreated colds and 2) the known spread of the cold from the nasal passages into the sinuses and middle ear.

Cold symptoms appear as early as 10 hours after a cold infection has started and increase in frequency and severity for 48 hours. (2, 13) After 48 hours, the symptoms usually begin to decline as the result of the natural course of the illness. For this reason, a cold treatment will do the most good when taken at the first recognition of symptoms. The treatment is thus applied over the period when most illness is expected (the first 3 days of infection).

Transferring Infection

A CAT scan of a patient with a cold involving the sinuses. The arrows point to thick fluid in the sinus cavities. Normally, the sinuses are full of air and appear black (see Anatomy).


A second reason for adopting early continuous cold treatment is that colds routinely involve the sinuses. Up to 87% of patients with early uncomplicated colds had thick fluid in the sinus cavity on CT scan examination. (40) Nose blowing creates high pressure in the nose and propels nasal fluid into the sinuses. (41) Nose blowing may be a cause of sinus disease in colds. Early continuous treatment reduces the frequency of sneezing and the amount of nasal secretions, thus reducing the need for nose blowing. (21-23)

During colds, up to 75% of patients have abnormal function of the eustachian tube (the tube connecting the back of the throat to the middle ear) and abnormal pressures in the middle ear. (42-45) Early and continuous treatment of colds may also reduce the frequency of ear complications, but no studies have been done on this question.