Which of the following propey of drug will enable it to be used in low concentrations -

Ans. is 'd' i.e., High affinity Most of the drugs act by binding to the receptors. o In general, the drug - receptor interaction is characterised by :? Binding of drug to receptor affinity Generation of response Efficacy or intrinsic activity. o By increasing affinity or efficacy drug can be used in low concentration. Lets see why? If the affinity of drug is increased, i.e. its ability to bind the receptors increases, it will form more numbers of drug-receptor complex --3 so less concentration will be required to produce an effect. Similarly, if the efficacy of a drug is increased the same effect can be produced with less number of drug-receptor complex --> so less concentration of drug is required.