Can I Alternate Paracetamol and Ibuprofen for My Child?
Yes, with the right timing. The rule is simple: never give the two medicines at the same time. Paracetamol runs on a 4 to 6 hour clock, ibuprofen on a 6 to 8 hour clock. When one is still working but the fever returns, the other can fill the gap.
Why parents are told to use both
Paracetamol works for about 4 to 6 hours. Ibuprofen works for about 6 to 8 hours. When a child has a persistent high fever, the temperature can climb back up before the next dose of the first medicine is due. Rather than wait it out or risk an early repeat dose, the other medicine can be given in between.
This is sometimes called "alternating", but a clearer way to describe it is: each medicine keeps its own schedule. They are never given together at the same moment.
The two clocks: how each medicine works
15 mg/kg per dose. Every 4 to 6 hours. Maximum 4 doses in 24 hours. Can be given with or without food.
Calculate correct dose here →10 mg/kg per dose. Every 6 to 8 hours. Maximum 3 doses in 24 hours. Give with food or milk to reduce stomach upset.
Calculate correct dose here →The two clocks are independent. Giving ibuprofen does not reset the paracetamol clock, and the other way around. If you gave paracetamol at 8 am, the next paracetamol dose is due between 12 pm and 2 pm regardless of whether you gave ibuprofen at 10 am.
A sample 24-hour schedule
This is one example for a child whose fever keeps returning. Each row is a dose. Times will shift based on when symptoms come back and when your child is awake.
| Time | Medicine | Next of the same is due |
|---|---|---|
| 8:00 am | Paracetamol | 12:00 pm – 2:00 pm |
| 11:00 am | Ibuprofen | 5:00 pm – 7:00 pm |
| 1:00 pm | Paracetamol | 5:00 pm – 7:00 pm |
| 6:00 pm | Ibuprofen | 12:00 am – 2:00 am |
| 7:30 pm | Paracetamol | 11:30 pm – 1:30 am |
| Overnight | Watch and rest | Only if needed and child wakes uncomfortable |
Daily totals in this example: 3 doses paracetamol, 2 doses ibuprofen. Both within the daily caps. Always recalculate based on your child's weight using the paracetamol and ibuprofen dosage calculators.
When alternating makes sense (and when it does not)
Consider using both medicines when:
- The fever is high (above 38.5°C) and keeps returning before the next dose of the first medicine is due.
- Your child is clearly distressed by the fever, not just warm to touch.
- A single medicine has not been enough to settle them for the past two or three doses.
Stick to one medicine when:
- The fever is mild (under 38.5°C) and your child is otherwise behaving normally.
- Your child is sleeping comfortably. Do not wake to give medicine on a schedule.
- Your child is already taking diclofenac. Ibuprofen and diclofenac are both NSAIDs and must not be combined.
- You are using ibuprofen and your child has chickenpox, is dehydrated, or has a bleeding disorder. Use paracetamol only.
- Your child is under 3 months old. See a doctor before giving any fever medicine.
What you need to track
When two medicines are in play, two clocks, two caps, and two different dosing intervals all have to be held in your head. This is the most common situation where caregivers accidentally give an extra dose, especially when grandparents or a partner is helping at different points in the day.
For each dose, write down:
- Which medicine (paracetamol or ibuprofen)
- The exact time it was given
- How much was given (in ml)
- Whether the child swallowed it all (or spat some out)
When to stop and call the doctor
Alternating is a short-term tool for a persistent high fever, not a long-term plan. Call your GP, polyclinic, or your nearest 24-hour A&E if:
- You have been using both medicines for more than 48 hours without the fever settling.
- The fever has reached 40°C or above and does not respond to either medicine.
- Your child is becoming drowsy, harder to rouse, or is refusing all fluids.
- You see a non-blanching rash (small red or purple spots that do not fade when a glass is pressed against them).
- Your child is under 3 months old with any fever at 38°C or above.
- You are unsure how much of either medicine has been given in the last 24 hours.
→ What to do if you think your child has had too much medicine
Frequently asked questions
Can I give paracetamol and ibuprofen at the same time?+
No. Each medicine has its own dosing interval and giving them together does not work better than giving the right dose of one. The safer approach is to use one medicine first, then if the fever returns before the next dose of the same medicine is due, give the other medicine to fill the gap.
How long should I wait between paracetamol and ibuprofen?+
There is no fixed minimum gap between switching from one medicine to the other, but each medicine has its own clock. Paracetamol can be repeated every 4 to 6 hours, ibuprofen every 6 to 8 hours. The simplest approach is to start with one, and if the fever returns before that medicine is due again, give the other.
When should I consider alternating?+
Most fevers are managed with one medicine alone. Consider using both only when a high fever (above 38.5°C) keeps returning before the next dose of the first medicine is due, or when your child is clearly distressed by the fever. Speak to your doctor if you are doing this for more than 48 hours.
Does alternating bring the fever down faster?+
It can give better symptom control in some children, but the goal is comfort, not a normal temperature. A fever that drops from 39.5°C to 38.2°C is doing its job even though it is still a fever. Do not chase a number with extra doses.
Can I give both medicines if my child has chickenpox?+
No. Ibuprofen is not recommended during chickenpox because it has been linked to a higher risk of serious skin infection. Use paracetamol only and call your doctor if the fever is hard to manage.
What if I lose track of which dose was last?+
Stop, write down what you remember, and wait until the safer of the two intervals has passed (6 hours from the last paracetamol, 8 hours from the last ibuprofen). If you are unsure whether your child had an extra dose, call your GP or polyclinic for advice. See our guide on what to do if you give too much.