When can my baby take a pain reliever without a call to the doctor first?

I would always recommend consulting the doctor first before giving any pain reliever to a child. This is because it may be difficult to gauge the appropriate amount of dosage for a child. Also, I’m always unsure if the medication is suitable for children. I think as a guide, for children under two years old, it is always better to give the doctor a call or to make a trip down before giving him/her any medication.