Pharmacodynamics 1 Pharmacodynamics Mechanisms of drug action and

Pharmacodynamics 1

Pharmacodynamics �Mechanisms of drug action and the relationship between drug concentration and responses in the body �How a medicine changes the body 2

Pharmacodynamics 3

Potency and Efficacy POTENCY � A drug more potent will produce a therapeutic effect at a lower dose, compared to another drug in the same class. EFFICACY � The magnitude of maximal response. � Efficacy is almost always more important than potency. 4

Agonist, Partial Agonist, and Antagonist �Agonist –drug that binds to a receptor and produces the same type of response as the endogenous chemical 5

Agonist, Partial Agonist, and Antagonist �Partial Agonist –drug that binds to a receptor and produces a weaker, or less efficacious, response than an agonist 6

Agonist, Partial Agonist, and Antagonist �Antagonist –drug that occupies a receptor and prevents the endogenous chemical from acting 7

Receptors and Drug Action RECEPTOR DRUG ACTION � Cellular macromolecule to � Triggers series of second which drug binds to cause a change in body chemistry or physiology � Drug attaches to receptors much like a key does to a lock messenger events within cell, which initiate drug’s action by either stimulating or inhibiting a normal activity of the cell 8

Cellular Receptors and Drug Action https: //www. youtube. com/watch? v=i 7_VTkh. R 3 UI 9