Question
| A. |
Therapeutic index is LD50/ED50 |
| B. |
Dose in which efficacy and toxicity can be balanced in an individual |
| C. |
Indicative of therapeutic index in a population vs individual |
| D. |
All of the Above |
|
Correct Answer » A Explanation |
 |
The therapeutic index (TI) is a measure of a drug’s safety margin. It compares the dose that produces a therapeutic effect with the dose that produces toxicity or lethality.
It is calculated as:
Therapeutic Index (TI) = LD₅₀ / ED₅₀
Where:
-
LD₅₀ (Median Lethal Dose) – dose that causes death in 50% of experimental animals
-
ED₅₀ (Median Effective Dose) – dose that produces the desired therapeutic effect in 50% of the population
A higher therapeutic index indicates a safer drug, because there is a wider margin between the effective dose and the toxic dose.