Test One

Question 0

Pharmacology

Answer 0

Study of properties and effects of drugs on living systems

Question 1

Drug names

Answer 1

Chemical, generic, trade

Question 2

Main sites of drug action

Answer 2

Ligand-gated channel G-protein coupled receptors Kinase-linked receptors Nuclear receptors

Question 3

Ligand-gated ion channel receptors

Answer 3

• Transmembrane proteins arranged around a central aqueous pore
• Channel opens in response to a ligand or voltage change

Question 4

G Protein-coupled receptors

Answer 4

• Transmembrane receptor coupled to intracellular system
• Subunits alpha, beta, and gamma
• GTP binds, alpha is released, starts second messenger system

Question 5

Kinase-linked receptors

Answer 5

• Transmembrane protein
• Intracellular tail has enzyme activity
• Binding causes phosphorylation, possibly a cascade

Question 6

Nuclear Receptors

Answer 6

• DNA-coupled receptors stimulate gene transcription
• Ligand must be lipophilic - normally steroids

Question 7

Mechanism of Action

Answer 7

Specific cellular changes mediated by a drug that cause a clinically evident response

Question 8

Receptor Occupancy

Answer 8

The number of receptors bound to the drug

Intensity is related to concentration and affinity

Question 9

Intrinsic activity

Answer 9

How much effect does the drug have on receptor action?

Question 10

Efficacy vs Potency

Answer 10

• Efficacy - the magnitude of a drug response
• Potency - how much drug is required to reach desired effect

Question 11

Competitive vs Noncompetitive Antagonist

Answer 11

• Competitive - reduces potency but not maximum effect. Normally competes for receptors
• Noncompetitive - reduces the efficacy but not potency. Different binding site

Question 12

Margin of Safety

Answer 12

TD₅₀ / ED₅₀

• The larger the margin, the safer the drug

Question 13

Hyper-reactivity

Answer 13

Response at low dose

Question 14

Hypo-reactivity

Answer 14

No response until a high dose administered

Question 15

Tolerance

Answer 15

Hyporeactivity that results from repeated drug administration

Question 16

Tachyphylaxis

Answer 16

Rapid onset of tolerance

Question 17

Idiosyncrasy

Answer 17

Unexpected deviation from normal or expected drug response

Question 18

Bioavailability

Answer 18

• Fraction of unchanged drug reaching the systemic circulation
• IV has 100% bioavailabiltiy

Question 19

Absorption

Answer 19

• Drug entry into systemic circulation from site of administration
• Depends on route of administration and physiochemical properties of drug

1. Simple diffusion
2. Facilitated diffusion
3. Active transport

• Compatibility depends on size and charge (ionization)

Question 20

Drug ionization and absorption

Answer 20

• Drugs that are weak acids are non-ionized in an acid solution
• Vice versa