An Overview of Cough Suppressants

Cough suppressants, also called antitussives, work by blocking your cough reflex. Products containing dextromethorphan and diphenhydramine are available over the counter (OTC), while codeine and hydrocodone require a prescription.

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.

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

Over-the-Counter

Dextromethorphan and diphenhydramine, active ingredients that suppress coughing, can be found in single over-the-counter formulations or in multi-symptom cold and flu products.

Dextromethorphan

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).

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

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. 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.

Brand name products containing dextromethorphan include:

• Children's Robitussin Cough Long-Acting
• Delsym
• Vicks DayQuil Cough
• Vicks Formula 44 Custom Care Dry Cough
• Zicam Cough MAX

Combination products are numerous.

Diphenhydramine

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 is found in many OTC cough and cold formulas, especially those designated for nighttime use because 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, as there are concerns regarding dizziness and cognitive impairment in those who are age 65 and over, these individuals should talk to a healthcare provider before taking diphenhydramine.

Brand name products containing diphenhydramine include:

• Benadryl
• Nytol
• PediaCare Children's Allergy
• Sominex
• Unisom

Combination products include:

• Advil PM
• Aleve PM
• Children's Dimetapp Nighttime Cold and Congestion
• Excedrin PM
• Robitussin Night Time Cough and Cold
• Theraflu Nighttime Severe Cold and Cough
• Triaminic Night Time Cold and Cough

Prescription

If coughing is a significant enough of a bother when dealing with a cold, an OTC cough suppressant should be sufficient for most. Your healthcare provider may consider a prescription cough suppressant if a drugstore option proves ineffective and you can't get comfortable or your cough is keeping you up at night.

Codeine

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 require a prescription or be available over-the-counter, though you may need a store clerk to get it for you. Codeine may be found in combination with antihistamines and decongestants.

The FDA revised labeling requirements for codeine-containing medications in 2018. They warn that they 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

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 researchers believe it acts directly on the cough center in the brain.

The danger is that hydrocodone 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 of the risk of 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

A Word From Verywell

Be sure to talk to your healthcare provider 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 work to relieve symptoms.