Reviewed on 9/16/2021

What Is Brompheniramine/Dextromethorphan/Phenylephrine and How Does It Work?

Brompheniramine/dextromethorphan/phenylephrine is an over-the-counter (OTC) product used for relief of cold symptoms.

  • Brompheniramine/dextromethorphan/phenylephrine is available under the following different brand names: Neo DM Suspension, Dimaphen DM, and Children's Dimetapp Cold & Cough.

What Are Dosages of Brompheniramine/Dextromethorphan/Phenylephrine?

Dosages of Brompheniramine/Dextromethorphan/Phenylephrine:

Dosage Forms and Strengths

Oral Solution

  • (1mg/5mg/2.5mg)/5mL

Dosage Considerations – Should be Given as Follows:

Relief of Cold Symptoms

  • Adults and children over 12 years: 4 teaspoons (20 mL) orally every four hours; not to exceed 120 mL/24 hours
  • Children 6-12 years: 2 teaspoons (10 mL) orally every four hours
  • Children under 6 years: Not recommended


How to Get Rid of a Cold: Natural Remedies See Slideshow

What Are Side Effects Associated with Using Brompheniramine/Dextromethorphan/Phenylephrine?

Side effects of brompheniramine/dextromethorphan/phenylephrine include:

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

What Other Drugs Interact with Brompheniramine/Dextromethorphan/Phenylephrine?

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

  • Severe interactions of brompheniramine/dextromethorphan/phenylephrine include:
  • Brompheniramine/dextromethorphan/phenylephrine has serious interactions with at least 36 different drugs.
  • Brompheniramine/dextromethorphan/phenylephrine has moderate interactions with at least 238 different drugs.
  • Brompheniramine/dextromethorphan/phenylephrine has mild interactions with at least 26 different drugs.

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist. Check with your physician if you have health questions or concerns.

What Are Warnings and Precautions for Brompheniramine/Dextromethorphan/Phenylephrine? 


This medication contains brompheniramine/dextromethorphan/phenylephrine. Do not take Neo DM Suspension, Dimaphen DM, or Children's Dimetapp Cold & Cough if you are allergic to brompheniramine/dextromethorphan/phenylephrine or any ingredients contained in this drug.

Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately.


Effects of Drug Abuse

  • No information available

Short-Term Effects

  • See "What Are Side Effects Associated with Using Brompheniramine/Dextromethorphan/Phenylephrine?”

Long-Term Effects

  • See "What Are Side Effects Associated with Using Brompheniramine/Dextromethorphan/Phenylephrine?”


  • Brompheniramine: May cause significant confusional symptoms; not for administration to premature or full-term neonates
  • Dextromethorphan: Do not take for persistent or chronic cough associated with smoking, asthma, or emphysema, or if it is accompanied by excessive phlegm unless directed by a healthcare provider; may decrease respiration rate
  • Phenylephrine: Caution in elderly patients, hyperthyroidism, myocardial disease, bradycardia, partial heart block, or severe arteriosclerosis

Pregnancy and Lactation

  • Use brompheniramine/dextromethorphan/phenylephrine with caution during pregnancy if the benefits outweigh the risks. Animal studies show risk and human studies are not available or neither animal nor human studies were done.
  • Brompheniramine/dextromethorphan/phenylephrine is excreted in breast milk. Use caution while breastfeeding.
  • Pregnant or breastfeeding patients should seek the advice of a health professional before using over-the-counter (OTC) drugs.


The common cold is one of the most common illnesses in the world. See Answer

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