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. Give the other medicine only if your child is still uncomfortable or 38.5°C or above about an hour after the first.
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 risk an early repeat dose, the other medicine can be given in between if your child is still uncomfortable or 38.5°C or above about an hour after the first.
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.
Use paracetamol, not ibuprofen, if dengue is possible, your child is vomiting or not drinking well, is under 3 months, or has had diclofenac. When not to use ibuprofen
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.
Only if your child is still uncomfortable at each point. Many children need fewer doses.
| 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 (38.5°C or above) 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 has had diclofenac or naproxen. These count as the NSAID, so do not give ibuprofen. Paracetamol can still be used on its own schedule.
- Your child is under 3 months old. See a doctor before giving any fever medicine.
- Your child is under 3 months, or weighs under 5 kg.
- Dengue is possible. In Singapore, a fever without a clear cause can be dengue in the first few days.
- Your child is vomiting repeatedly, or not drinking well.
- Your child has chickenpox.
- Your child has already had diclofenac (for example a suppository from the clinic) or naproxen. These are the same class of medicine as ibuprofen, so never give them within each other’s dosing window.
- Your child has asthma that has got worse with ibuprofen or aspirin before.
- Your child has kidney problems, a stomach ulcer, or a bleeding disorder.
If you are not sure, ask your pharmacist or GP before giving it.
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 995 now if your child has a fever and any of these:
- !A seizure lasting more than 5 minutes (give rectal diazepam if a doctor has prescribed it, and still call)
- !Struggling to breathe (skin pulling in under the ribs, nostrils flaring, or grunting), pauses in breathing, or lips turning blue or grey
- !Cannot be woken, or floppy and not responding to you
- !A rash of small red or purple spots that does not fade when you press a glass on it
- !Swelling of the lips, tongue, or face, with any difficulty breathing
- !Cold, clammy, or mottled skin, with drowsiness or restlessness
Go to the nearest 24-hour A&E or children's emergency now if:
- !Refusing all fluids
- !A baby under 3 months with a temperature of 38.0°C or above
- !A first febrile seizure, even if it has stopped
- !After a seizure: confused, still drowsy after 30 minutes, or more than one seizure in a day
- !A stiff neck, or crying in pain when bending the head forward
- !Unusually drowsy or hard to wake, but can be woken
- !Dengue warning signs as the fever comes down: tummy pain, repeated vomiting, bleeding gums or nose, or very tired
- !No urine or wet nappy for 12 hours or more
- !No tears when crying, sunken eyes, or a very dry mouth
- !Cannot keep any fluids down
- !Green vomit
- !A temperature above 40°C that is not coming down, and your child seems unwell
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.
If you are unsure how much of either medicine was given in the last 24 hours, go to the nearest 24-hour A&E. Call 995 if your child is drowsy or unwell.
→ 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. Give the other only if your child is still uncomfortable or 38.5°C or above about an hour after the first. Each medicine keeps its own clock and daily maximum. Use paracetamol, not ibuprofen, if dengue is possible, your child is vomiting or not drinking well, is under 3 months, or has had diclofenac.
How long should I wait between paracetamol and ibuprofen?+
Never give both at the same moment. Give the other medicine only if your child is still uncomfortable or 38.5°C or above about an hour after the first. Each medicine keeps its own clock and daily maximum. Paracetamol can be repeated every 4 to 6 hours, ibuprofen every 6 to 8 hours.
When should I consider alternating?+
Most fevers are managed with one medicine alone. Consider using both only when a high fever (38.5°C or above) 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. Use paracetamol, not ibuprofen, if dengue is possible, your child is vomiting or not drinking well, is under 3 months, or has had diclofenac.
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 how much was given, go to the nearest 24-hour A&E. Call 995 if your child is drowsy or unwell. See our guide on what to do if you give too much.