Cough suppressants


Cough suppressants are medicines that prevent or stop a person from coughing.


Cough suppressants act on the center in the brain that controls the cough reflex. They are meant to be used only to relieve dry, hacking coughs associated with colds and flu. They should not be used to treat coughs that bring up mucus or the chronic coughs associated with smoking, asthma , emphysema, or other lung problems.

The most effective cough suppressants are narcotics. Heroin, which is not approved for medicinal use in the United States, and codeine have been widely used to stop coughs. These compounds, in addition to relieving coughs, also relieve pain , cause sedation, and are addictive. The most popular drug in this class is dextromethorphan, which is quite safe and is available without prescription. Dextromethorphan is an ingredient in most over-the-counter cough preparations:

  • Vicks Formula 44
  • Drixoral Cough Liquid Caps
  • Sucrets Cough Control
  • Benylin DM

The letters DM in a product's name normally indicates the presence of dextromethorphan, but it is always best to read the ingredients. Dextromethorphan works best in liquid formulations but is also available in capsules, lozenges, and tablets.

General use

Dextromethorphan is used for the temporary relief of coughs caused by minor throat and bronchial irritation such as may occur with common colds or with inhaled irritants. Dextromethorphan is most effective in the treatment of chronic, nonproductive cough.

Dextromethorphan has been reported to be effective in reversing some of the adverse effects of methotrexate, a drug that has found use in many conditions including cancer, psoriasis , and some types of arthritis.


Lozenges containing dextromethorphan hydrobromide should not be used in children younger than six years of age. Liquid-filled capsules containing the drug should not be used in children younger than 12 years of age.

Dextromethorphan is not meant to be used for coughs associated with asthma, chronic bronchitis , or other lung conditions. It should not be used for coughs that produce mucus.

A lingering cough could be a sign of a serious medical condition. Patients with a cough that lasts more than seven days or is associated with fever , rash, sore throat , or lasting headache should have medical attention. Parents should call a physician as soon as possible if their child has these symptoms.

Side effects

Dextromethorphan rarely causes side effects but has been reported to cause dizziness , drowsiness, and stomach upset. There have been rare reports of vomiting caused by dextromethorphan.

Although dextromethorphan is very safe, it can cause problems when taken in too large a dose. In overdose, dextromethorphan can cause extreme dizziness, shallow breathing, and coma.


Dextromethorphan has no clinically significant interactions with medications that are likely to be given to children. However, dextromethorphan should not be used in combination with narcotic analgesics such as meperidine or codeine, since dextromethorphan will increase the side effects of the analgesic.

Parental concerns

Lozenges containing dextromethorphan hydrobromide should not be used in children younger than six years of age. Liquid-filled capsules containing the drug should not be used in children younger than 12 years of age. Doses must be measured carefully. Measuring teaspoons should be used in place of household teaspoons.

Adolescent behavior must be observed, since some multi-ingredient over-the-counter cough remedies have become drugs of abuse. While these products are not addictive, they are toxic when misused.


Chronic —Refers to a disease or condition that progresses slowly but persists or recurs over time.

Narcotic —A drug derived from opium or compounds similar to opium. Such drugs are potent pain relievers and can affect mood and behavior. Long-term use of narcotics can lead to dependence and tolerance. Also known as a narcotic analgesic.

Nonproductive —A cough in which no mucus is coughed up, also called dry cough.

See also Expectorants .



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American Academy of Emergency Medicine. 555 East Wells Street, Suite 1100, Milwaukee, WI 53202–3823. Web site:

American Academy of Pediatrics. 141 Northwest Point Boulevard, Elk Grove Village, IL 60007–1098. Web site:


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Nancy Ross-Flanigan Samuel Uretsky, PharmD

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