Allergy & antihistamine · Second-generation antihistamine
Cetirizine
Cetirizine is a modern non-drowsy antihistamine used for the temporary relief of allergy symptoms and hives.
OTCPregnancy: cautionKidney warningLiver warningAlcohol interactionPaediatric useSenior precautionOverview & typical uses
Cetirizine is a modern non-drowsy antihistamine used for the temporary relief of allergy symptoms and hives.
Primary uses
- Runny nose, sneezing, itchy and watery eyes from allergies
- Itchy skin and hives (urticaria)
How it works
Blocks histamine H1 receptors involved in allergic responses, easing itching, sneezing, and watery eyes without significant brain sedation.
Available forms & strengths
- Tablet — 5 mg, 10 mg (Oral)
- Oral syrup — 5 mg / 5 mL (Oral) · Paediatric option
- Oral drops — 10 mg / mL (Oral)
General precautions & contraindications
Do not use if
- Known allergy to cetirizine or hydroxyzine
- Severe kidney disease without medical supervision
Pregnancy
Use with caution — discuss with clinician. Human data are reassuring; discuss with a clinician for regular use in pregnancy.
Breastfeeding
Use with caution — discuss with clinician. Small amounts pass into milk. Occasional short-term use is usually acceptable.
Kidney considerations
- Reduce total daily amount in significant kidney disease.
Liver considerations
- Discuss with a clinician if you have severe liver disease.
Paediatric use
Suitable from 2 years in the correct paediatric formulation.
Older adults
Well tolerated; kidney function may influence dosing.
Common side effects
- Mild drowsiness or tiredness in some people
- Dry mouth
- Mild headache
Serious warnings — seek help if these appear
- Serious allergic reaction (very rare) — swelling of the face or trouble breathing
- Severe drowsiness in sensitive individuals
Drug interactions
May increase drowsiness in sensitive individuals.
Additive sedation.
Food & alcohol precautions
May amplify drowsiness in some people.
Alcohol
- Alcohol may increase drowsiness in sensitive individuals.
Storage, missed dose & overdose
Storage
Store below 25 °C in a dry place, out of reach of children.
If a dose is missed
Take when remembered unless close to the next scheduled time — do not double up.
Overdose
Overdose commonly causes marked drowsiness. Seek medical advice for large overdoses.
What to monitor
- Take care with driving until you know how it affects you.
Frequently asked questions
It is less sedating than older antihistamines, but some people still feel drowsy — try it first at home.
Usually within 30 to 60 minutes; effects last around 24 hours.
Many people take it daily during allergy season under pharmacist guidance.
Medical references
- British National Formulary — Cetirizine — BNF (NICE)
- WHO Model Formulary — World Health Organization
Content last reviewed: 2025-01-01
Medical disclaimer
This information is for educational purposes only and should not replace professional medical advice. Please consult a licensed pharmacist or clinician for advice tailored to your personal circumstances.