Chlorpheniramine
CHLOR-TRIMETON
Pronunciation: klor-fen-IR-a-meen
What it isFirst-generation H1 antagonist; allergic rhinitis and cold remedies.
Why this oneIt is less sedating than diphenhydramine but remains common in multi-ingredient cold products.
What limits itAnticholinergic burden and sedation make it poor for older adults and unsafe before driving.
FDA-approved for
- allergy (~1949)
FDA label
Read the full label on DailyMed ↗
| FDA dosing | Population | Start | Target | Max |
|---|---|---|---|---|
| Temporary relief of hay fever/upper respiratory allergy symptoms (sneezing, runny nose, itchy watery eyes, itchy nose/throat) | Adults & children ≥12 y | 1 tablet (4 mg) q4–6h PRN | 1 tablet (4 mg) q4–6h PRN | 6 tablets (24 mg)/24 h |
| Temporary relief of hay fever/upper respiratory allergy symptoms | Children 6 to <12 y | 1/2 tablet (2 mg) q4–6h PRN (break tablet in half) | 1/2 tablet (2 mg) q4–6h PRN | 3 whole tablets (12 mg)/24 h |
Renal Undefined
Hepatic Undefined
Dose no more often than every 4 to 6 hours; do not exceed the stated 24-hour tablet limit.
Instructions
- Take every 4 to 6 hours, or as directed by a doctor.
- Children 6 to under 12 years: break the tablet in half.
- Do not use in children under 6 years of age.
Available strengths
- ER tab 12 mg
- tab 4 mg
- sol 2 mg/5 mL
- inhaler 5 mg/mL
Contraindications
- Do not use to make a child sleepy
Cautions
- Ask a doctor before use if you have glaucoma, a breathing problem (emphysema, chronic bronchitis), or difficulty urinating due to enlarged prostate.
- Drowsiness may occur — use caution when driving or operating machinery.
- Excitability may occur, especially in children.
- Avoid alcohol; alcohol, sedatives, and tranquilizers may increase drowsiness — ask a doctor/pharmacist before use if taking sedatives or tranquilizers.
- Do not use to make a child sleepy; do not use in children under 6 years.
Adverse reactions
- Drowsiness
- Excitability (especially in children)
Pregnancy If pregnant, ask a health professional before use (OTC drug-facts statement).
Lactation If breast-feeding, ask a health professional before use (OTC drug-facts statement).
Cost
| Strength | #/mo | generic $/unit | CostPlus | |
|---|---|---|---|---|
| 12 mg | ER tab | per unit | not offered |
NO BOXED WARNINGS
Principal riskAnticholinergic burden and sedation, so it is poor in the elderly
Classes and tags
Clinical profile
Serotonin and MAOI
Provisional washout figures
Evidence confidenceModerate