For a child with fever or pain, paracetamol and ibuprofen are different medicines and can be used together or alternated when one alone is not enough. The key safety point is dosing: always use the correct dose for the child's age and weight from the product made for children, and use the measuring device provided rather than a kitchen spoon.
Many paediatric guidelines recommend starting with one medicine and only adding or switching to the other if the child remains distressed, to keep dosing simple and reduce errors. Ibuprofen should be given with food and avoided in dehydrated children or those with certain conditions like asthma flares or chickenpox unless advised.
Never exceed the stated number of doses in 24 hours. Seek urgent care for a baby under 3 months with a fever, a child who is very drowsy, has a rash that does not fade under pressure, a stiff neck, breathing difficulty, or is not drinking or passing urine.