Drug-receptor interaction is explained by the ‘law of mass action’: Proposes that the rate of binding is directly proportional to the product of the concentrations of the reactants Can be demonstrated by the equation: [D] is drug[R] is receptor [D-R] is...
Term Affinity Definition A measure of quantity of drug needed to bind to receptors (how avidly a drug binds) Description Drugs of high affinity bind to a critical number of receptors at low concentration compared with rugs of low affinity which require a high...
KD is the uquilibrium dissociation constant describing the relationship between association and dissociation rates It can also be described as: The drug concentration at which 50% of the maximum receptor population is occupied, usually expressed in units of...
The KD is a physiochemical constant – it the same for a given receptor and drug combination in any tissue, in any species It can therefore be used: To quantitatively compare the affinity of different drugs on the same receptor To identify an unknown...