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

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

3. 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

4. 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?

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

6. agonist
response
effect
dose

7. agonist
response
partial
agonist
effect
dose

8. agonist
response
+ partial
agonist
effect
dose

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

10. 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)

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