How can one decide the dose of basic medications like Cyclopam, Ondem, Allergra for a child . My daughter is 3 year and 6 months old

A. Hello, your baby girl is 3.5 years old and if you want to give her any medicine then first you should weigh her and then dose is calculated per kg like…… For fever paracetamol is given 15mg/kg body weight at every 6/8 hours sos