Therapeutic index is a measure of which of the parameters?: (A) Efficacy, (B) Adverse effects, (C) Safety, (D) Potency
Answer is C. Therapeutic index is a measure of the margin of safety of a drug. Therapeutic index = Median lethal dose/Median effective dose. One estimate of a drug's margin of safety is the ratio LD50/ED50, the therapeutic index, which is a statement of how selective the drug is in producing it's desired versus its adverse effects.