<prompt> Efficacy of the drug refers toAffinity of the drug to bind to the receptorAffinity of the drug that binds to the receptor and activates itDose that required to to produce responseMaximum response a drug can produce  <response>: Efficacy means effectiveness, i.e. the ability of something, e.g. a medicine, to produce the results you want Ref-KDT 7e p54 