What is Polytussin DM syrup?

Polytussin DM syrup is an over-the-counter cough medicine that contains the cough suppressants dextromethorphan hydrobromide and guaifenesin. It is used to temporarily relieve coughs caused by minor throat and bronchial irritation, such as the common cold, inhaled irritants, or flu. Polytussin DM syrup helps thin mucus, making coughs more productive, and suppresses the urge to cough.

What are the active ingredients in Polytussin DM syrup?

The active ingredients in Polytussin DM syrup are:

  • Dextromethorphan hydrobromide – a cough suppressant that blocks cough reflexes in the brain
  • Guaifenesin – an expectorant that helps thin mucus secretions and make coughs more productive

Both of these medications work together to temporarily relieve coughing. Dextromethorphan suppresses the urge to cough, while guaifenesin loosens mucus. Other inactive ingredients provide flavoring and sweetening.

What is dextromethorphan hydrobromide?

Dextromethorphan hydrobromide is a cough suppressant in the class of drugs known as antitussives. It works by acting on receptors in the brain to raise the threshold for coughing. This means it requires more irritation or stimulation to trigger a cough reflex.

When taken as directed, dextromethorphan provides temporary relief for coughing symptoms. It does not treat the underlying cause of the cough.

Some common side effects of dextromethorphan may include:

  • Drowsiness
  • Dizziness
  • Nausea
  • Vomiting
  • Constipation
  • Stomach pain

Dextromethorphan should not be taken with certain medications, including antidepressants, due to potential interactions. It also should not be taken by people with breathing issues or coughs due to smoking, asthma, emphysema, or chronic bronchitis.

What is guaifenesin?

Guaifenesin is an expectorant that helps loosen congestion and thin mucus secretions in the airways. It works by drawing more water into the bronchial passages, which helps reduce mucus viscosity and make it easier to cough up.

Guaifenesin has a different mechanism than cough suppressants. Rather than blocking the cough reflex, it helps make coughs more productive at expelling phlegm and mucus from the lungs and sinuses.

Possible mild side effects of guaifenesin may include:

  • Nausea
  • Vomiting
  • Upset stomach
  • Diarrhea

Guaifenesin may cause drowsiness or dizziness in some people. It also may complicate uric acid kidney problems if taken long-term at high doses.

How much dextromethorphan and guaifenesin are in Polytussin DM?

Each 5mL dose (one teaspoon) of Polytussin DM syrup contains:

  • Dextromethorphan hydrobromide – 10mg
  • Guaifenesin – 100mg

The adult dosing instructions recommend 10mL every 4 hours or 20mL every 6-8 hours. No more than 120mL should be taken in 24 hours.

For children ages 6-12, the dose is 5mL every 4 hours or 10mL every 6-8 hours, up to 60mL per day. Children under age 6 should not take Polytussin DM.

What are the uses and indications for Polytussin DM syrup?

Polytussin DM syrup is intended for the temporary relief of coughs and congestion caused by:

  • Common cold
  • Flu
  • Hay fever
  • Sinusitis
  • Allergies
  • Inhaled irritants

It can be used to alleviate coughing so that rest or sleep is possible. The expectorant guaifenesin may help bring up mucus and clear chest congestion.

Polytussin DM should not be used for persistent coughs, or coughs that produce excessive mucus. It also should not be used for coughs caused by smoking, asthma, emphysema, chronic bronchitis, or coughs that occur with too much phlegm unless directed by a doctor.

What are the side effects of Polytussin DM syrup?

Possible side effects of Polytussin DM include:

  • Drowsiness
  • Dizziness
  • Nausea
  • Vomiting
  • Upset stomach
  • Constipation
  • Headache
  • Fatigue

More serious side effects are unlikely if taken according to package directions. Seek medical help if you experience symptoms like rash, itching, swelling, breathing problems, or rapid heartbeat.

Do not take Polytussin DM with alcohol, sedatives, tranquilizers, or other medicines that cause drowsiness. It may cause dangerous interactions or increase side effects. The cough suppressant can interfere with mental alertness even when taken as directed.

Who should not take Polytussin DM syrup?

Polytussin DM should not be taken by people who have certain medical conditions or are taking certain medicines. Use is contraindicated for:

  • Children under age 6
  • People with breathing problems like asthma, COPD, or emphysema
  • People with a cough that produces excessive mucus or phlegm
  • People taking antidepressants (MAO inhibitors)

The dextromethorphan may interact with certain antidepressants and cause side effects. People with chronic coughs like smoker’s cough or chronic bronchitis should not take cough suppressants without medical advice.

Is Polytussin DM the same as Delsym?

Polytussin DM and Delsym are both over-the-counter cough and cold medicines, but they have some differences:

Polytussin DM Delsym
Contains dextromethorphan and guaifenesin Contains dextromethorphan only
Suppressant and expectorant Cough suppressant only
Relieves coughs for 4-6 hours Relieves coughs for 12 hours
Liquid syrup Extended release liquid
Generic formula Brand name formula

While both medicines contain the cough suppressant dextromethorphan, Delsym does not have the expectorant guaifenesin. Delsym lasts longer (12 hours) compared to the regular release Polytussin DM (4-6 hours).

What warnings and precautions should I know about Polytussin DM?

Important warnings and precautions for Polytussin DM include:

  • Do not exceed recommended doses. An overdose can cause serious side effects.
  • Do not take with alcohol or medicines that cause drowsiness.
  • Use caution when driving or operating machinery.
  • This medication may be habit forming with high doses for extended periods.
  • Not for use in coughs that produce excess mucus unless directed by a doctor.
  • Ask a doctor before use if you have cough with excessive phlegm, asthma, chronic bronchitis, emphysema, or other breathing problems.

Polytussin DM should not be used by children under age 6. Measure doses carefully using the provided dosing cup. Discontinue use and contact your doctor if side effects like rash, increased coughing, or breathing problems occur.

Can I take Polytussin DM while pregnant or breastfeeding?

Polytussin DM has not been studied for safety during pregnancy or breastfeeding. The effects of dextromethorphan on unborn children or breastfed infants are unknown.

Pregnant or breastfeeding women should speak with their doctor before taking Polytussin DM. It may be recommended to try alternative therapies like humidifiers, saline sprays, or acetaminophen before using cough medicine.

How long does Polytussin DM syrup last?

The effects of Polytussin DM generally last for 4 to 6 hours after taking a dose. The dextromethorphan suppresses coughs, while the guaifenesin helps loosen congestion during this time.

Do not take more than the recommended amount within 24 hours. Taking more than directed does not increase effectiveness and can lead to an overdose.

If coughs persist for more than 1 week or return after stopping use, be sure to contact your doctor. Chronic coughs may need treatment for an underlying illness.

Can I take Polytussin DM every day?

Polytussin DM should only be taken on an as-needed basis to relieve cough and cold symptoms. It is intended for temporary relief and should not be taken regularly every day without medical advice.

Taking cough medicine like Polytussin DM too often can lead to abuse or dependence, especially in children. An addiction could occur with long-term use at higher than recommended dosages.

It’s also important not to use cough suppressants for chronic, persistent coughs lasting more than 1 week. Seek medical evaluation for coughs that recur over time or do not respond to medicine.

How long does Polytussin DM stay in your system?

The cough suppressing effects of the dextromethorphan in Polytussin DM generally last for 4 to 6 hours. However, trace amounts can remain in your system for 1 to 2 days after taking it.

Dextromethorphan is metabolized by enzymes in your liver. It has an average half-life of 3 to 6 hours in adults but may last longer in some people.

Factors like your age, liver function, metabolism, and dosage impact how long dextromethorphan stays in your system. Larger doses take longer to clear from the body.


Polytussin DM is an over-the-counter cough syrup that provides temporary relief from coughing and congestion. It contains a combination of the cough suppressant dextromethorphan and the expectorant guaifenesin. While generally safe when used as directed, side effects are possible and precautions should be taken, especially concerning overdose, drug interactions, and use in young children. As with any medicine, speak with a doctor if you have additional questions or concerns before taking Polytussin DM.

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