Levocetirizine (Xyzal) Pediatric Dose Calculator
Label dose by age, once each evening: 1.25 mg at 6 months to 5 years, 2.5 mg at 6 to 11 years, 5 mg from 12 years. The calculator gives a weight-based estimate in mL; check it against the age dose.
Levocetirizine = Xyzal
Comparing Xyzal with other daily allergy medicines?
Levocetirizine is the active form of cetirizine, given once in the evening. These pages help when you are comparing it with cetirizine and other lower-drowsiness antihistamines.
Start with the main daily-option chooser
Use the parent-facing chooser if you are still deciding where levocetirizine fits among the common routine options.
Compare with cetirizine (Zyrtec)
Levocetirizine is closely related to cetirizine, so the cetirizine route is often the clearest comparison anchor.
Liquid and tablet guide
Review once-daily timing, formulation notes, and practical administration tips for levocetirizine.
Compare with loratadine (Claritin)
Open loratadine when the goal is a less-sedating once-daily daytime option.
Compare with fexofenadine (Allegra)
Open fexofenadine when low sleepiness risk is the main comparison point.
label dose by age
How the levocetirizine dose is worked out
The FDA label sets the levocetirizine dose by age, once daily in the evening. The calculator has no age field: it gives a weight-based estimate, and its caps use weight bands that stand in for age (about 20 kg for 6 years, 40 kg for 12 years). A child who is heavy or light for their age can get a different dose from the label dose, so always use the age dose.
Formula
Calculator: mL per dose = (weight in kg × mg/kg/day), capped by weight band, ÷ 0.5 mg per mL. Use the label dose for the child's age when it differs.
Worked example
A 5-year-old weighing 21 kg at 0.125 mg/kg/day: the calculator gives 2.5 mg, twice the 1.25 mg label dose for 6 months to 5 years, which should not be exceeded. A 7-year-old weighing 18 kg: the calculator gives 1.25 mg, but the label dose for 6 to 11 years is 2.5 mg (5 mL). Use the age dose.
Safety checks before using the result
- Do not use in children 6 months to 11 years with impaired kidney function (label).
- Do not give with cetirizine or other antihistamines unless a clinician directs it.
- Stop and ask a doctor for trouble urinating; get emergency care for swelling of the face or trouble breathing.
Practical dosing guide
Before you measure the dose
Levocetirizine is dosed by age on the label, once daily in the evening. Start from the age dose, then measure it.
- 2.5 mg/5 mL liquid
- Xyzal liquid is 0.5 mg per mL: 1.25 mg is 2.5 mL, 2.5 mg is 5 mL and 5 mg is 10 mL.
- Once-daily rhythm
- The label directs once-daily dosing in the evening.
- Compare with cetirizine
- Families often compare levocetirizine with cetirizine when they want a daily option and need to balance symptom control, product form, and how sleepy the child feels.
Levocetirizine pediatric medication summary
Levocetirizine (Xyzal) pediatric dose by age from the FDA label, once daily in the evening: 1.25 mg at 6 months to 5 years, 2.5 mg at 6 to 11 years, 5 mg from 12 years, with mL for 0.5 mg/mL liquid.
Dose by age, once daily in the evening: 1.25 mg (6 months to 5 years), 2.5 mg (6 to 11 years), 5 mg (12 years and older).
Liquid is 0.5 mg/mL (2.5 mg/5 mL): 1.25 mg is 2.5 mL and 2.5 mg is 5 mL.
Levocetirizine indications and common pediatric uses
What the US labels cover for levocetirizine in children, and where guidelines place it.
Allergic rhinitis (hay fever and year-round allergies)
Allergic rhinitis (hay fever and year-round allergies): Give once daily in the evening.
Chronic hives (chronic idiopathic urticaria)
Chronic hives (chronic idiopathic urticaria): Hives that last more than 6 weeks are called chronic urticaria; see a clinician.
How to give Levocetirizine
- How to measure and give levocetirizine to children safely.
- Use only the enclosed dosing cup or an oral syringe. Check the strength: 1.25 mg is 2.5 mL and 2.5 mg is 5 mL of 0.5 mg/mL liquid.
- Give it in the evening at about the same time each day.
Levocetirizine side effects, contraindications, and interactions
Levocetirizine is generally well tolerated. In children's trials the most common side effects were fever, cough, sleepiness and nosebleed (6 to 12 years), and fever, diarrhea, vomiting and ear infection (1 to 5 years).
Common side effects
- 6 to 12 years: fever 4%, cough 3%, sleepiness 3%, nosebleed 2% (label; these trials used 5 mg, twice the labeled 2.5 mg).
- 1 to 5 years: fever 4%, diarrhea 4%, vomiting 4%, ear infection 3% (label; trials used 1.25 mg twice daily, twice the labeled dose).
- 6 to 11 months: diarrhea and constipation were most common (label).
Safety checks
- Swelling of the face, lips or tongue, or trouble breathing: Possible allergic reaction.
Drug interactions
- Review the full medication list with a clinician or pharmacist before combining therapies.
Levocetirizine mechanism and clinical pearls
Levocetirizine blocks histamine H1 receptors, easing sneezing, runny nose, itching and hives.
The label doses levocetirizine by age
1.25 mg, 2.5 mg or 5 mg once in the evening. The children's doses should not be exceeded.
Levocetirizine is the active half of cetirizine, so a cetirizine-sized dose would be about double.
Contraindicated in children 6 months to 11 years with impaired kidney function (label).
Rarely, strong itching starts within a few days of stopping after months or years of use; restarting or tapering may help (label).
Frequently asked questions about Levocetirizine
It depends on age, once daily in the evening: 6 months to 5 years 1.25 mg (2.5 mL of 0.5 mg/mL liquid); 6 to 11 years 2.5 mg (5 mL); 12 years and older 5 mg (10 mL), or 5 mL if that controls symptoms (OTC label: 5 or 10 mL depending on severity). Under 2 years, only if a prescriber directs it.
No. The label doses levocetirizine by age, and the doses for children under 12 should not be exceeded because they already give about the same exposure as the adult 5 mg dose. The calculator above works from weight and caps the result, so check it against the age dose.
Yes. Xyzal is a brand of levocetirizine. Check the strength on the bottle: the liquid is 0.5 mg/mL (2.5 mg/5 mL).
Levocetirizine is the active half of cetirizine, so its doses are about half the cetirizine dose. Do not give both together, and do not use either if your child has reacted to the other.
The label directs once-daily evening dosing. Drowsiness can occur, especially at the start.
Children 6 months to 11 years with impaired kidney function should not take it (prescription label), and OTC Children's Xyzal says do not use with kidney disease. Ask your clinician.
Rarely, strong itching starts within a few days of stopping after months or years of daily use. The label says symptoms may improve by restarting or tapering levocetirizine. Talk to your clinician.
Not as a routine treatment. Dermatology guidelines do not recommend non-sedating antihistamines for eczema (atopic dermatitis) unless the child also has hives or hay fever.
Sources reviewed for Levocetirizine
Xyzal (levocetirizine dihydrochloride) tablets and oral solution – prescribing information
DailyMed (U.S. National Library of Medicine)
SourceChildren's Xyzal Allergy 24HR (levocetirizine) oral solution – Drug Facts
DailyMed (U.S. National Library of Medicine)
SourceDykewicz MS, et al. Rhinitis 2020: A practice parameter update. J Allergy Clin Immunol. 2020;146(4):721-767.
Journal of Allergy and Clinical Immunology
SourceZuberbier T, et al. The international EAACI/GA²LEN/EuroGuiDerm/APAAACI guideline for the definition, classification, diagnosis, and management of urticaria. Allergy. 2022;77(3):734-766.
Allergy (Wiley)
SourceSidbury R, et al. Guidelines of care for the management of atopic dermatitis: section 3. J Am Acad Dermatol. 2014;71(2):327-349.
Journal of the American Academy of Dermatology
Source