How do you know?
Do you know it's strep? Has your child seen a doctor? When the doctor prescribed the Amoxicillin
why didn't he/she give you a dosing schedule? In general, Amoxicillin is not commonly used for strep.
Public answers on healthtap aren't intended for individual treatment, prescription or diagnosis.
I think it's best if you call the child's doctor who prescribed the medicine and ask for dose.