Chapter 3: Receptor Theory and Pharmacodynamics (2) Prof.R.D.Ye 2012-09-19
Chapter 3: Receptor Theory and Pharmacodynamics (2) Prof. R.D. Ye 2012-09-19
Dose-Response Curve A B 1.0- 1.0- 0.5- 0.5 0.0- 0.0- 0 102030 40 50 -10 8-76 -9 Agonist(nM) Log [Agonist] Hyperbolic curve Sigmoidal curve
Dose-Response Curve Hyperbolic curve Sigmoidal curve
Dose-response relationship The relationship between the concentration of a drug at the receptor site and the magnitude of the response is called the dose- response relationship.Depending on the purpose of the studies,this relationship can be described in terms of a graded (continuous) response or a quantal (all-or-none)response
Dose‐response relationship • The relationship between the concentration of a drug at the receptor site and the magnitude of the response is called the dose‐ response relationship. Depending on the purpose of the studies, this relationship can be described in terms of a graded (continuous) response or a quantal (all‐or‐none) response
Efficacy and Potency of Dose-Response Curve. Drug A is more potent than Drug B,but both show Drug C shows same efficacy. lower potency and lower efficacy than Drug A or B. 100 50 Drug A Drug B Drug C Log drug concentration ↑ 1 foB8 O A fOr Di积gB Figure 2.7 Typical dose response curve for drugs showing differences in potency and efficacy.EDso drug dose that shows 50%of maximal response
Efficacy and Potency of Dose-Response Curve
Relationship of Affinity and Efficacy of Drug and Potency and Efficacy(maximum activity)of Dose-Response Curve. 100- 1007 A 50 B 50 Potency xeW 88 Intrinsic activity f(Efficacy and Affinity) f(Efficacy） 0 2 -1 0 -1 0 Log ([Agonist]/KA) Log ([Agonist]KA) Drug A is more potent than Drug B,and they both have the same efficacy Drug C is less efficacious;it probably has the same affinity as Drug B
Relationship of Affinity and Efficacy of Drug and Potency and Efficacy (maximum activity) of Dose-Response Curve. Drug A is more potent than Drug B, and they both have the same efficacy A B C Drug C is less efficacious; it probably has the same affinity as Drug B