– Why are certain animal medications given by weight, even if the animal is a tiny bit over the limit?

Question

For example: Most flea medications range from 5-20 pounds, 21-55 pounds, and 56+ pounds. Why would a pet who is 22 pounds require a dose that is also suitable for a 55 pound pet? Isn’t there a concern of over medicating since there’s only a 2 pound difference?

In: Chemistry

Answer 1

It depends on the therapeutic index. Many drugs have a wide range of levels that will give the desire effect before you reach toxic levels. Other drugs aren’t so forgiving.