Cetirizine Pediatric Dose Calculator
Age-based cetirizine dosing for children, with maximum doses, age limits and sources. Enter age and weight for the dose in mg and syrup mL or tablets.
Pediatric dosing
Allergic rhinitis / urticaria
Cetirizine dose chart by age and weight
Allergic rhinitis / urticaria. Weights are WHO/IAP reference medians for age — always dose on the measured weight.
| Age | Weight | Dose (mg) | Syrup 5 mg/5 mL | Frequency |
|---|---|---|---|---|
| 6 months | 7.6 kg | 2.5 mg | 2.5 mL | Once daily |
| 9 months | 8.6 kg | 2.5 mg | 2.5 mL | Once daily |
| 1 year | 9.3 kg | 2.5 mg | 2.5 mL | Once daily |
| 18 months | 10.6 kg | 2.5 mg | 2.5 mL | Once daily |
| 2 years | 11.8 kg | 2.5 mg | 2.5 mL | Once daily |
| 3 years | 14.1 kg | 2.5 mg | 2.5 mL | Once daily |
| 4 years | 16.2 kg | 2.5 mg | 2.5 mL | Once daily |
| 5 years | 17.5 kg | 2.5 mg | 2.5 mL | Once daily |
| 6 years | 19 kg | 5 mg | 5 mL | Once daily (or 5 mg twice daily) |
| 8 years | 24.4 kg | 5 mg | 5 mL | Once daily (or 5 mg twice daily) |
| 10 years | 31.1 kg | 5 mg | 5 mL | Once daily (or 5 mg twice daily) |
| 12 years | 39.4 kg | 10 mg | 10 mL | Once daily |
Strengths in the calculator
- Syrup 5 mg/5 mL (Oral)
- Tablet 10 mg (Oral)
Different strength on your bottle? Use “Different strength on the bottle?” under the result.
Safety
Contraindications and cautions
- Severe renal impairment — halve the dose in moderate impairment.
Pregnancy and breastfeeding
Legacy FDA category B. Reassuring human data; a preferred antihistamine in pregnancy if one is needed.
Compatible; watch for infant drowsiness.
Clinical notes
Evening dosing reduces daytime drowsiness.
Adult and adolescent (≥40 kg) dose
10 mg — Once daily (max 10 mg per dose).
Other names and brands
Also known as Cetirizine hydrochloride, CTZ.
- India: Okacet, Alerid
- USA: Zyrtec
- UK: Zirtek
Brand examples only — products and strengths vary by country. Always check the label.
Frequently asked questions
What is the cetirizine dose for children?
Allergic rhinitis / urticaria: 6 months to <6 years: 2.5 mg per dose · once daily; 6 years to <12 years: 5–10 mg per dose · once daily (or 5 mg twice daily); ≥12 years: 10 mg per dose · once daily. Usual duration: As needed. Always use the child's measured weight and check the strength on the bottle.
How many mL of syrup 5 mg/5 mL for an 11.8 kg child?
For allergic rhinitis / urticaria, an 11.8 kg child (about 2 years) needs 2.5 mg per dose — 2.5 mL of Syrup 5 mg/5 mL, once daily. Recalculate with the child's actual weight.
From what age can cetirizine be given?
Age range in PediaRx: ≥6 months – adult. The calculator does not calculate a dose below 6 months. Each indication can have its own age and weight limits, shown with its regimen.
Is cetirizine safe in pregnancy?
Legacy FDA category B. Reassuring human data; a preferred antihistamine in pregnancy if one is needed.
Sources and editorial process
- Cetirizine — US labelling — DailyMed (U.S. National Library of Medicine)
- BNF for Children — Cetirizine hydrochloride — NICE / BMJ Group / Royal Pharmaceutical Society
Dosing data last updated 2026-09-27. PediaRx is built and maintained by Dr. Shounak Pal, MBBS (Medical Officer, Government of West Bengal, India — founder and developer of PediaRx). Every regimen is encoded with explicit units, maximum doses and age/weight limits and is checked by automated tests before publication. Report an error: hello@pediarx.com.
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Clinical disclaimer: reference tool for qualified health professionals. Verify every dose against current guidance and the product label before prescribing.
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