Question

What is the name for the measure of a drug's relative safety for use, computed by the ratio of the lethal dose for 50 percent of the population over the effective dose?

Answer 1

It is called THERAPEUTIC INDEX. Therapeutic index is the comparison of the amount of a particular drug that causes the desired therapeutic effects and the amount that causes toxicity. The index can be low or high. A drug with a low therapeutic index will require only a small increase in dose to produce toxic effects in users.