1. Pharmacology Introduction

2. Terminology Drug Therapeutic Effect Drug Indication Contraindication
Pure chemical compound with specific chemical structure
Biological effects
Chemical effects
Therapeutic Effect
Intended effect of a drug
Drug Indication
Therapeutic use of a drug
Contraindication
Situation when a particular drug should NOT be used

3. Undesired Effects of Drugs
Side Effects
Nuisance more than dangerous
E.g. dry mouth, sedation,
Adverse Effects
May be harmful
E.g. darrhea, vomitting, CNS disturbances
Toxic Effects
Drug poisoning
Most drugs exhibit all effects depending on dose

4. Basic Concepts Site of Action Mechanism of Action
Location within the body where the drug exerts its therapeutic effect
E.g. aspirin acts at the hypothalamus to reduce fever
Mechanism of Action
How a drug produces its effects
Anesthetic produce loss of pain by interrupting sensory nerve conduction

5. Receptor Site
Drug usually exerts action once binding to specific cell in the body
Often site of binding is a specific receptor
Receptor site is usually synonymous with Site of Action
E.g. morphine binds to opiod receptors in the brain to reduce pain
Same receptors as endorphins in exercise or fight of flight

6. Agonists and Antogonists
Drugs that bind to specific receptors and produce a drug action are termed Agonists
Drugs that bind to specific receptors but do not produce any drug action are termed Antagonists
Antagonists are used as blocking drugs
Naloxone is an antogonist to morphine receptor
Used for treatment in morphine overdose

7. Dose-Response Curve
Dose is the exact amount of a drug that is administered in order to produce and effect
The graph of the response versus a given dose is the dose-response curve
The response is often proportional to the dose
Not always
May hit a ceiling above which no therapeutic effect is observed, but adverse effects may be
ED50
Effective dose that elicits 50% of maximal response
Measure of potency

8. Agonist Dose Response Curves
Full agonist
Partial agonist
Response
Dose

9. Relative Potency
hydromorphone
morphine
codeine
Analgesia
aspirin
Dose

10. Effectiveness, toxicity, lethality
ED50 - Median Effective Dose 50; the dose at which 50 percent of the population or sample manifests a given effect; used with quantal dr curves
TD50 - Median Toxic Dose 50 - dose at which 50 percent of the population manifests a given toxic effect
LD50 - Median Toxic Dose 50 - dose which kills 50 percent of the subjects

11. Quantification of drug safety
TD50 or LD50
Therapeutic Index =
ED50

12. Drug A
100
sleep
death
Percent
Responding 50
ED50
LD50
dose

13. Drug B
100
sleep
death
Percent
Responding 50
ED50
LD50
dose

14. Time-Response Curve
Relationship of drug response and duration of the action

15. Drug Safety All drugs will act as poisons if taken in excess
Therapeutic effect is distinguished from toxic effect by dose
Factors such as route of administration, absorption, and drug metabolism will influence amount of drug reaching site of action

16. Nomenclature All drugs typically have three names Chemical Generic
Gives the chemical structure of the compound
Generic
Often abbreviated form of chemical name
Trade
Name given by manufacturer to drug

17. Drug Schedules Schedule 1 Schedule 2 Schedule 3 Schedule 4 Schedule 5
High abuse potential- no accepted medical use
E.g. heroin, not to be prescribed
Schedule 2
High abuse potential – accepted medical use
E.g. morphine, cocaine, no refills without new prescription
Schedule 3
Moderate abuse potential – accepted medical use
E.g. codeine plus another drug, can be refilled 5 x in 6 months
Schedule 4
Low abuse potential – accepted medical use
E.g. valium, phenobarbital, can be refilled 5 x in 6 months
Schedule 5
Limited abuse potential – accepted medical use
No limitations on refill of prescription