Question

A new drug was tested in an in vitro system. It was found that only one enantiomer ofthe racemic pair bound substantially to a specific receptor, whereas the other enantiomer showed a negligible binding. Which of the following terms best * ?defines this property A) Intrinsic activity B) Affinity C) Stereo-selectivity O D) Potency 5 us

Answer 1

1.Intrinsic activity : The term intrinsic activity refers to the maximal possible effect that can be produced by a drug. It is defined by the drug receptor relationships for a drug that acts on receptors. Receptors pharmacology assumes that the effect of the drug is proportional to the number of receptors occupied, implying that a greater effect is produced by occupation of more receptors which a maximal effect can be produced by without occupation of all the receptors.

B.Affinity :affinity is how avidly a drug binds its receptors or how the chemical forces that cause a substance to bind its receptor. It refers to how much attra tion there is between a drug a drug and a receptor, like a magnet to metel.

C. Stereo selectivity : process is one in which one stereo isomers predominates over another when rwo or more may be formed. If the products are enantiomer, the reaction Enatiosective.if they are diastereoisomers, the reaction is diasteteoselective.

Potancy 5 :potancy is a measure of drug a tivity expressed in terms of the amount required to produce an effect of given intensity