I have read your question,
Since your boy is eating and drinking a lot of water with fever , I think These Are the Symptoms of a viral fever
so you need not worry , motrin
) is an anti inflammatory drug generally prescribed to reduce fever , but since your son seems to have a viral fever , Antibiotic and anti-histamines are required as well .
I would suggest you to take him to nearest general physician for further medication.Please use the medicines prescribed by the doctor only.
I hope your son gets well soon,