TherapeutIc index is a measure of:
The gap between the therapeutic effect DRC (Dose Response Curve)and the adverse effect DRC defines the safety margin or the therapeutic index of a drug. So it is a measure of safety Therapeutic index =median lethal dose /median effective dose or LD 50 /ED 50 Ref; KD Tripathi Pharmacology 7th edition (page no;56 )
Safety
Potency
Efficacy
Selectivity
General pharmacology