Montelukast Pediatric Dose Calculator
Age-based montelukast 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
Asthma prevention / allergic rhinitis
Montelukast dose chart by age and weight
Asthma prevention / allergic rhinitis. Weights are WHO/IAP reference medians for age — always dose on the measured weight.
| Age | Weight | Dose (mg) | Syrup 4 mg/5 mL (where available) | Frequency |
|---|---|---|---|---|
| 6 months | 7.6 kg | 4 mg | 5 mL | Once daily in the evening |
| 9 months | 8.6 kg | 4 mg | 5 mL | Once daily in the evening |
| 1 year | 9.3 kg | 4 mg | 5 mL | Once daily in the evening |
| 18 months | 10.6 kg | 4 mg | 5 mL | Once daily in the evening |
| 2 years | 11.8 kg | 4 mg | 5 mL | Once daily in the evening |
| 3 years | 14.1 kg | 4 mg | 5 mL | Once daily in the evening |
| 4 years | 16.2 kg | 4 mg | 5 mL | Once daily in the evening |
| 5 years | 17.5 kg | 4 mg | 5 mL | Once daily in the evening |
| 6 years | 19 kg | 5 mg | — | Once daily in the evening |
| 8 years | 24.4 kg | 5 mg | — | Once daily in the evening |
| 10 years | 31.1 kg | 5 mg | — | Once daily in the evening |
| 12 years | 39.4 kg | 5 mg | — | Once daily in the evening |
Strengths in the calculator
- Oral granules 4 mg sachet (Oral)
- Syrup 4 mg/5 mL (where available) (Oral)
- Chewable tablet 4 mg (Oral — do not split)
- Chewable tablet 5 mg (Oral — do not split)
- Tablet 10 mg (Oral — do not split)
Different strength on your bottle? Use “Different strength on the bottle?” under the result.
Safety
Pregnancy and breastfeeding
Legacy FDA category B. Reassuring data; continue if needed for asthma control.
Probably compatible.
Clinical notes
Not for acute attacks. FDA boxed warning (2020): serious neuropsychiatric events (sleep disturbance, agitation, suicidality) — counsel families and stop if they occur. For allergic rhinitis, reserve for children who cannot use other treatments.
Adult and adolescent (≥40 kg) dose
10 mg — Once daily in the evening (max 10 mg per dose).
Other names and brands
- India: Montair
- USA: Singulair
- UK: Singulair
Brand examples only — products and strengths vary by country. Always check the label.
Frequently asked questions
What is the montelukast dose for children?
Asthma prevention / allergic rhinitis: 6 months to <6 years: 4 mg per dose · once daily in the evening; 6 years to <15 years: 5 mg per dose · once daily in the evening; ≥15 years: 10 mg per dose · once daily in the evening. Usual duration: As prescribed; review at 4–8 weeks. Always use the child's measured weight and check the strength on the bottle.
How many mL of syrup 4 mg/5 mL (where available) for an 11.8 kg child?
For asthma prevention / allergic rhinitis, an 11.8 kg child (about 2 years) needs 4 mg per dose — 5 mL of Syrup 4 mg/5 mL (where available), once daily in the evening. Recalculate with the child's actual weight.
From what age can montelukast 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 montelukast safe in pregnancy?
Legacy FDA category B. Reassuring data; continue if needed for asthma control.
Sources and editorial process
- Montelukast (Singulair) — US prescribing information — DailyMed (U.S. National Library of Medicine)
- BNF for Children — Montelukast — 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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