Fundamentals of Drug Action Jack W. Strandhoy, PhD Wake Forest University School of Medicine

OxyContin effect time toxicity, euphoria peak pain relief onset duration time

Pharmacokinetics Describes where the drug goes in the body, and how much is present at any time: Onset, duration, time of peak effect, half-life; rates of absorption, distribution, metabolism, and elimination (ADME) Can be affected by the physical form of the drug and the route of administration

Pharmacodynamics Describes the mechanisms of drug action and the relationship between drug concentration and effect Why and how do drugs produce actions? Why do similar drugs differ in their effects?

Drugs and Receptors are like a Lock and Key →Selectivity for receptor types

agonist response effect dose

agonist response partial agonist effect dose

agonist response + partial agonist effect dose

response dose no effect heroin agonist partial agonist buprenorphine naloxone antagonist dose

Potency: A > B = C (takes less to 50% max) ↑ A B Response or Effect C Dose → Potency: A > B = C (takes less to 50% max) Efficacy: A = B > C (maximal effect)

Glossary of terms Pharmacokinetics Pharmacodynamics Agonist Antagonist Partial agonist Second messengers Dose-response relationship Efficacy Potency Selectivity ADME