Hey there,
My son is 10 years old, weighs 59 pounds, and was on 60mg for 5 days, then tapered down to 40mg for 5 days, then down to 20, then 10, now he is permanently on 10mg once every other day.
So, I guess a shorter response would have been, 60mg is safe for someone who weighs less than 60 pounds. Good luck!