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Ru-Hist Forte Side Effects

Generic name: chlorpheniramine / phenylephrine / pyrilamine

Note: This document contains side effect information about chlorpheniramine / phenylephrine / pyrilamine. Some dosage forms listed on this page may not apply to the brand name Ru-Hist Forte.

Applies to chlorpheniramine / phenylephrine / pyrilamine: oral suspension, oral suspension extended release.


You should not use this medicine if you have severe coronary artery disease, diabetes, overactive thyroid, asthma, pneumonia, or other breathing problems.

Do not use chlorpheniramine, phenylephrine, and pyrilamine if you have used an MAO inhibitor in the past 14 days. A dangerous drug interaction could occur. MAO inhibitors include isocarboxazid, linezolid, methylene blue injection, phenelzine, and tranylcypromine.

Do not give this medicine to a child younger than 6 years old. Misuse of this medicine may cause death in very young children.

Do not use this medicine to make a child sleepy.

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 chlorpheniramine, phenylephrine, and pyrilamine and call your doctor at once if you have:

  • confusion, hallucinations;

  • feeling nervous or irritable;

  • trouble sleeping;

  • little or no urination;

  • a seizure (convulsions);

  • numbness or tingly feeling;

  • a light-headed feeling, like you might pass out;

  • pounding heartbeats or fluttering in your chest; or

  • severe headache, blurred vision, pounding in your neck or ears.

Serious side effects may be more likely in older adults.

Common side effects may include:

  • nausea, constipation, loss of appetite;

  • rash or itching;

  • increased sweating;

  • dry mouth, nose, or throat;

  • blurred vision;

  • headache, dizziness; or

  • feeling restless or excited (especially in children).

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 chlorpheniramine/phenylephrine/pyrilamine: oral liquid, oral suspension, oral suspension extended release, oral tablet, oral tablet extended release.

Nervous system

Nervous system side effects including drowsiness and sedation have been reported.[Ref]


Gastrointestinal side effects including dryness of the mucous membranes have been reported.[Ref]


1. PDR Generics. Montvale, NJ: Medical Economics. 1998.

2. Product Information. Poly Hist PD (chlorpheniramine / phenylephrine / pyrilamine). Poly Pharmaceuticals Inc. 2005.

Further information

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.