Therapeutic index of a drug is indicative of: (A) Measure of safety, (B) Measure of adverse effect, (C) Dose range across which the drug can be safely administered, (D) Measure of efficacy
Answer is A. Ans: A (Measure of safety)Ref: Thripathi 5 ed. Pg. 46Therapeutic index is a measure of drug safety.Therapeutic index (TD)It is the ratio of the dose that produces toxicity to the dose that produces a clinically desired or effective response. A large value indicates that there is a wide margin between doses that are effective and doses that are toxic.TD = TD50/ED50 TD50 is the dose that produces a toxic effect in half the population.ED 50 is the dose that produces a desired effect in half the population.