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Chlorpheniramine

Brand names: Chlor-Trimeton, in many cold medicines

Chlorpheniramine is an older antihistamine for sneezing, runny nose, and itchy eyes. It's in many cold and allergy combinations.

Brand namesChlor-Trimeton, in many cold medicines
Type of medicineAntihistamine (allergy medicine)
Prescription?Over the counter
ImportantThis page is general information, not a prescription. Don't start, stop, or change a medicine without talking to your provider or pharmacist.

Overview

It causes more drowsiness than newer antihistamines.

What it's used for

  • Allergy symptoms
  • Runny nose from colds

How to take it

  • Follow the label.
  • Check combination products so you don't double up.
  • Don't give cough and cold medicines to children under 4.

Your dose depends on your health and other medicines. Always follow your prescription label, and ask your pharmacist if anything is unclear.

Side effects

Common side effects

  • Sleepiness
  • Dry mouth
  • Dizziness
Call your provider todayTrouble peeing or confusion

Warnings

  • Older adults are more likely to become confused or fall.

Other medicines, foods, and alcohol

  • Alcohol and sedating medicines add to drowsiness.

Tell your provider and pharmacist about every medicine, vitamin, and supplement you take.

Pregnancy and breastfeeding

Ask your provider.

Missed doses, overdose, and storage

If you miss a dose

This medicine is often taken only when needed. If you take it on a schedule, take a missed dose when you remember, unless it's almost time for the next one. Don't double up.

If someone takes too much

Call Poison Control at 1-800-222-1222 or get help online at poison.org. Call 911 if the person collapses, has a seizure, has trouble breathing, or can't be woken.

Storing it

Store at room temperature, away from heat and moisture (not in the bathroom), and out of reach of children and pets.

Conditions it's used for

Sources

Last updated 2026-11-13.