M-Hist DM Side Effects
Generic name: brompheniramine / dextromethorphan / phenylephrine
Note: This document contains side effect information about brompheniramine / dextromethorphan / phenylephrine. Some dosage forms listed on this page may not apply to the brand name M-Hist DM.
Applies to brompheniramine / dextromethorphan / phenylephrine: oral liquid, oral suspension extended release.
Do not give this medication to a child younger than 4 years old. Always ask a doctor before giving a cough or cold medicine to a child. Death can occur from the misuse of cough and cold medicines in very young children.
You should not use this medication if you have severe constipation, a blockage in your stomach or intestines, or if you are unable to urinate.
Do not use this medication if you have used an MAO inhibitor such as furazolidone (Furoxone), isocarboxazid (Marplan), phenelzine (Nardil), rasagiline (Azilect), selegiline (Eldepryl, Emsam, Zelapar), or tranylcypromine (Parnate) in the last 14 days. A dangerous drug interaction could occur, leading to serious side effects.
Get emergency medical help if you have any of these signs of an allergic reaction while taking brompheniramine/dextromethorphan/phenylephrine: hives; difficult breathing; swelling of your face, lips, tongue, or throat.
Stop using this medicine and call your doctor at once if you have a serious side effect such as:
fast, slow, or uneven heart rate;
severe headache, mood changes, hallucinations;
tremor, seizure (convulsions);
easy bruising or bleeding, unusual weakness;
urinating less than usual or not at all;
feeling short of breath; or
dangerously high blood pressure (severe headache, blurred vision, buzzing in your ears, anxiety, confusion, chest pain, uneven heartbeats, seizure).
mild dizziness, drowsiness;
dry mouth, nose, or throat;
feeling nervous, restless, or irritable;
blurred vision; or
sleep problems (insomnia).
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.
For Healthcare Professionals
Applies to brompheniramine/dextromethorphan/phenylephrine: oral liquid, oral suspension extended release.
The manufacturer has not provided adverse event information.[Ref]
More about M-Hist DM (brompheniramine / dextromethorphan / phenylephrine)
Related treatment guides
1. "Product Information. Dimaphen (brompheniramine-pseudoephedrine)." Major Pharmaceuticals Inc (2022):
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
Some side effects may not be reported. You may report them to the FDA.