Dimetane Side Effects Center

Last updated on RxList: 10/4/2022
Dimetane Side Effects Center

Medical Editor: John P. Cunha, DO, FACOEP

What Is Dimetane?

Dimetane (brompheniramine, phenylpropanolamine, codeine) is a combination antihistamine, nasal decongestant, antitussive (anti-cough) medication used to relieve coughs and upper respiratory symptoms, including nasal congestion, associated with allergy or the common cold. The brand name Dimetane is discontinued, but generic versions may be available.

What Are Side Effects of Dimetane?

Dimetane may cause serious side effects including:

  • hives,
  • difficulty breathing,
  • swelling of your face, lips, tongue, or throat,
  • extreme drowsiness,
  • confusion,
  • hallucinations,
  • nervousness,
  • restlessness,
  • dizziness,
  • seizure, and
  • little or no urination

Get medical help right away, if you have any of the symptoms listed above.

Common side effects of Dimetane (brompheniramine, phenylpropanolamine, codeine) include:

  • sedation,
  • drowsiness,
  • dry mouth/nose/throat,
  • thickening of bronchial secretions,
  • constipation,
  • blurred vision,
  • dizziness,
  • nervousness, or
  • restlessness

Seek medical care or call 911 at once if you have the following serious side effects:

  • Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
  • Serious heart symptoms such as fast, irregular, or pounding heartbeats; fluttering in your chest; shortness of breath; and sudden dizziness, lightheadedness, or passing out;
  • Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, loss of coordination, feeling unsteady, very stiff muscles, high fever, profuse sweating, or tremors.

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

Dosage for Dimetane

The dose of Dimetane for adults and children 12 years of age and over is 2 teaspoonfuls every 4 hours.

What Drugs, Substances, or Supplements Interact with Dimetane?

Dimetane may interact with monoamine oxidase inhibitors (MAOIs), other drugs that cause drowsiness (such as antidepressants, alcohol, other antihistamines, pain relievers, anxiety medicines, seizure medicines, and muscle relaxants), over-the-counter cough, cold, allergy, diet, pain, or sleep medications. Tell your doctor all medications and supplements you use.

Dimetane During Pregnancy or Breastfeeding

It is unknown if Dimetane will be harmful to a fetus. Tell your doctor if you are pregnant or could become pregnant during treatment. This drug passes into breast milk. Infants are especially sensitive to the effects of antihistamines, and serious side effects could occur in a nursing infant. Consult your doctor before breastfeeding. Withdrawal symptoms may occur if you suddenly stop taking this medication.

Additional Information

Our Dimetane (brompheniramine, phenylpropanolamine, codeine) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Dimetane Consumer Information

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Stop using brompheniramine and call your doctor at once if you have:

  • extreme drowsiness;
  • confusion, hallucinations;
  • feeling nervous, restless, or dizzy;
  • a seizure; or
  • little or no urination.

Side effects such as dry mouth, constipation, and confusion may be more likely in older adults.

Common side effects may include:

  • drowsiness;
  • blurred vision;
  • constipation;
  • flushing (warmth, redness, or tingly feeling);
  • dry mouth, nose, or throat; or
  • feeling restless or excited (especially in a child).

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


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Dimetane Professional Information


The most frequent adverse reactions to this product are: sedation; dryness of mouth, nose and throat; thickening of bronchial secretions; dizziness. Other adverse reactions may include:


Codeine can produce a drug dependence of the morphine type, and therefore has the potential for being abused. Psychic dependence, physical dependence, physical dependence and tolerance may develop upon repeated administration of this drug and it should be prescribed and administered with the same degree of caution appropriate to the use of other oral narcotic medications.

The product is subject to the Federal Controlled Substances Act (Schedule V).

Read the entire FDA prescribing information for Dimetane (Brompheniramine, Phenylpropanolamine, and Codeine)

© Dimetane Patient Information is supplied by Cerner Multum, Inc. and Dimetane Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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