An Overview of Cough Suppressants

Cough suppressants, also called antitussives, work by blocking your cough reflex. There are both over-the-counter (OTC) and prescription options. Understanding how they work, which are appropriate for different age groups, and when they might be useful can help ensure you are using them safely. Because they often are found in multi-symptoms cold and flu products, you must label to know what is included.

If you have a severe or chronic cough that lasts longer than three weeks, it should be evaluated by your health care provider.

Over-the-Counter Cough Suppressants

There are two active ingredients to look for when buying OTC cough medications—dextromethorphan and diphenhydramine. They can be found in single formulations or in combination cough and cold formulations.


Dextromethorphan is the primary over-the-counter cough suppressant. It is often the active ingredient in cough syrups, gel caps, lozenges, and combination cough and cold formulas. It is appropriate for a nonproductive cough (a dry cough that doesn't bring up phlegm).

Dextromethorphan is a synthetically manufactured chemical cousin to codeine. It is absorbed into the bloodstream and crosses into the brain where it binds to receptors in the medulla oblongata cough center, suppressing the cough reflex.

If taken in high dosage, dextromethorphan has psychoactive effects, including euphoria, visual distortion, loss of coordination, nausea, and vomiting, and it is a known drug of abuse, especially in younger people.

At higher than the recommended dosage, dextromethorphan has the potential for serious side effects and even death in young children. As such, it is one of the cough and cold medications that the U.S. Food and Drug Administration (FDA) says should not be used by children younger than age 2.

It is questionable as to how much relief a child may get with dextromethorphan if they have a respiratory infection. Studies have not shown any OTC product improves acute cough significantly in children or adults.

Brand name products containing dextromethorphan include Delsym, Children's Robitussin Cough Long-Acting, Vicks DayQuil Cough, Vicks Formula 44 Custom Care Dry Cough, and Zicam Cough MAX. Combination products are numerous. Often, DM included in the name indicates it contains dextromethorphan.


Diphenhydramine is an antihistamine commonly used for allergy symptoms and runny nose in colds. It is also classified by the FDA as an antitussive, but it is not considered to be the first-line choice. It acts in the medulla of the brain to suppress the cough reflex.

Diphenhydramine found in many OTC cough and cold formulas, especially those designated for nighttime use, as it causes drowsiness. These medications should not be given to children younger than 4 years old. They should only be used with caution by children under age 12. As well, there are concerns as to dizziness and cognitive impairment in those who are age 65 and over, who should talk to their doctor before taking diphenhydramine.

Brand name products containing diphenhydramine include Benadryl, Nytol, PediaCare Children's Allergy, Sominex, and Unisom. Combination products include Advil PM, Aleve PM, Excedrin PM, Robitussin Night Time Cough and Cold, Children's Dimetapp Nighttime Cold and Congestion, Theraflu Nighttime Severe Cold and Cough, Triaminic Night Time Cold and Cough.

Prescription Cough Suppressants


Codeine is a classic antitussive. It is an opiate that is converted by the liver into morphine, which then has many actions in the brain, including suppressing the cough reflex, sedation, and pain relief. Depending on state regulation, it may be available in some over-the-counter formulations, or it may only be available by prescription. It may be found in combination with antihistamines and decongestants.

The FDA revised labeling requirements for codeine-containing medications in 2018. They warn that should not be taken by children and teens under age 18.

Prescription cough and cold medicines containing codeine include:

  • Tuxarin ER, Tuzistra XR (codeine, chlorpheniramine)
  • Triacin C (codeine, pseudoephedrine, tripolidine)
  • Generic combinations of codeine and promethazine
  • Generic combinations of codeine, phenylephrine, and promethazine


Hydrocodone is a semisynthetic opiate the FDA classifies as an antitussive and analgesic (pain reliever). It isn't precisely known how it suppresses coughs, but they believe it acts directly on the cough center in the brain. The danger is that it can depress breathing at higher doses, and it can have psychoactive effects. As well, it can be addicting. Medications containing hydrocodone should be avoided by people who may be recovering from an addiction to opioids because they risk relapse.

The FDA labeling requirements established in 2018 note that hydrocodone-containing medications should not be used by anyone under age 18.

Prescription cough and cold medications containing hydrocodone include:

  • FlowTuss, Obredon (hydrocodone and guaifenesin)
  • Hycofenix, Rezira (hydrocodone, pseudoephedrine, guaifenesin)
  • Tussionex, Pennkinetic, Vituz (hydrocodone, chlorpheniramine, pseudoephedrine)
  • Generic combinations of hydrocodone and homatropine

Giving prescription cough medicines to kids or teens is dangerous. They can slow their breathing to dangerous levels and can even be fatal.

A Word From Verywell

Be sure to talk to your doctor if you have a lingering cough. Coughs—especially chronic coughs that last more than four to six weeks—can be caused by many conditions and illnesses. It is best to try to treat the underlying cause rather than just trying to relieve symptoms.

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Article Sources
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Additional Reading
  • "FDA Issues Alert on Tussionex, a Long-Acting Prescription Cough Medicine Containing Hydrocodone.” FDA News Press Release 11 Mar 08. U.S. Food and Drug Administration.
  • "Questions and Answers About FDA’s Enforcement Action Regarding Unapproved Hydrocodone Drug Products.” U.S. Food and Drug Administration 01 Oct 07.