Dosage needs to be appropriate for the strength given (Nurofen Syringe comes with medicine) :

Suggested Dosage based on 10mg/kg/dose

3 - 6 mths - (average weight 6-8kg) 3-4ml
6 - 12 mths - (8-10kg) 4-5ml
Children 1- 3 years (10 - 14kg) 5-7ml
Children 3- 5 years (14-18kg) 7-9ml
Children 5- 7 years (18 - 22kg) 9-11ml
Children 7- 9 years (22 - 28kg) 11-14ml
Children 9- 12 years (28-40kg) 14 - 20ml

• Not for use in babies under 3 months of age.
• Do not exceed the recommended dose.
• Excessive use can be harmful and increase the risk of heart attack, stroke or liver damage.
• If your child's symptoms worsen or persist consult your doctor.
• Do not use if:
  • you or your child has a stomach ulcer, or other stomach disorders, kidney, liver or heart problems.
  • allergic to ibuprofen, aspirin or other anti-inflammatory medicines. Stop use and see your doctor immediately if you have an allergic reaction
  • you are in the last 3 months of pregnancy
• Unless a doctor has told you to, do not use:
  • if taking other medicines containing ibuprofen or other anti-inflammatory medicines or other medications.
  • if your child is under 12 months of age
  • for more than 3 days at a time
  • if you or your child have asthma
  • if you are trying to become pregnant or during the first 6 months of pregnancy
  • in children suffering from chickenpox (varicella)
  • in children suffering from dehydration through diarrhoea and/or vomiting
  • if you are aged 65 years or over