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Alternating paracetamol and ibuprofen: when it makes sense and how to avoid mistakes

Creator: OUMM
Published: 2026-09-29

Alternating is sometimes used when one medicine does not bring relief. Guidelines do not recommend it routinely because the main risk is a dosing mistake. Start with one medicine.

Written by OUMM

Last updated: 29 September 2026

One medicine first

NICE (NG143): do not give medicines only to bring the temperature down. Give one medicine; consider the other only if your child is still distressed before the next dose of the first is due. Never give both at once "to be sure". If your child is asleep, do not wake them to give a medicine.

The rule

Each medicine keeps its own interval and daily limit from its product's leaflet: paracetamol at least 4 h after the previous paracetamol (6 h, and 4 h only between doses of up to 10 mg/kg (Apap dla dzieci Forte, Pedicetamol); Paracetamol Hasco: 4 h only between doses of up to 10.5 mg/kg per the calculator and the Android app), ibuprofen at least 6 h after the previous ibuprofen. About 3 hours between the two different medicines is a practical convention of the calculator below, not a leaflet or guideline figure.

The earliest time for the other medicine

When it makes sense

The child is clearly distressed before the first medicine's interval is over.
A doctor recommended it for a specific illness.

When not

Under 3 months or under 5 kg: alternating does not apply; ask a doctor.
Dehydration or chickenpox: ibuprofen is out. Dehydration itself strains the kidneys: the ibuprofen leaflets warn of kidney problems in dehydrated children.
Kidneys: combining the two medicines raises the risk to the kidneys, especially in a dehydrated child, not only with kidney disease. The Paracetamol Hasco leaflet warns that using paracetamol together with NSAIDs increases the risk of kidney problems; the Ibufen leaflet says to avoid using different painkillers together for a long time.
Two caregivers giving medicine without a shared log. The biggest risk is a double dose of the same medicine.

How to avoid mistakes

Write down time, medicine and millilitres for every dose in one place both parents can see. What counts is the interval of the same medicine, not "since the last medicine of any kind".

Check the official source

These numbers are conversions from leaflets and guidelines. Before giving a medicine, confirm them at the source:

NHS: paracetamol for children · NHS: ibuprofen for children
NICE NG143: fever in under 5s · AAP HealthyChildren.org
Polish medicines register (URPL): official leaflets of the products listed here
Leaflets in the Polish register: Apap dla dzieci Forte (40 mg/ml) · Paracetamol Hasco (120 mg/5 ml) · Panadol dla dzieci (120 mg/5 ml) · Pedicetamol (100 mg/ml) · Czopki 125 mg (125 mg) · Czopki 250 mg (250 mg) · Czopki 500 mg (500 mg) · Nurofen dla dzieci Forte (200 mg/5 ml) · Ibum (100 mg/5 ml) · Ibum Forte (200 mg/5 ml) · Ibufen dla dzieci (100 mg/5 ml) · Ibufen dla dzieci Forte (200 mg/5 ml) · Ibuprom dla dzieci Forte (40 mg/ml) · MIG dla dzieci (20 mg/ml) · MIG dla dzieci Forte (40 mg/ml) · Nurofen czopki 60 mg (60 mg) · Nurofen czopki 125 mg (125 mg)
Dosing sources: every leaflet table as the calculator and the Android app encode it, the leaflet date, the register link and every added rule, with its reason
Your own country's medicines regulator and the leaflet in the box always take precedence.

Tired of keeping track on a scrap of paper?
Oh Fever records what you gave and when. Free for one child.

iPhone and Apple Watch

Shows the time since the last dose, the doses recorded in 24 hours and the leaflet tables and sentences word for word, with a link to the official leaflet. It does not calculate or suggest doses.

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Android

Also shows the row of the leaflet table for your child's weight and age, counts down to the next dose the leaflet allows and warns before the daily limit is crossed.

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