Pharmacology Weeks 1-3

Question 1

pharmacokinetics vs pharmacodynamics

Answer 1

pharmacokinetics: what body does to drugs
pharmacodynamics: what drugs do to body

Question 2

List various types of receptors and describe the fundamental differences between them

Answer 2

ion channel: fastest, ligand causes to open. ex. ACh
G-protein coupled:second messengers ex Epi
R couples to enzyme: membrane tyr kinases. ex GFs
Intracellular: slowest, gene expression, ex steroids

Question 3

agonist

Answer 3

affinity and intrinsic activity (exerts an effect)

• partial agonist: has affinity but less than full intrinsic activity and given receptor
• inverse agonist: inactivates constitutively active receptors (rare)

Question 4

antagonist

Answer 4

affinity but lacks intrinsic activity

• reversible and irreversible
• chemical antagonist: drug that inhibits action of another drug
• phyl antagonist: counteracts physiological effects of another compound via DIFFERENT receptor

Question 5

graded dose reponse curve

Answer 5

Plot réponse vs log[dose]

• assess efficacy (Emax=max response) and potency (50% Emax=measure of how much drug is needed)
• steep slope=more potent

Question 6

quantal dose response curves

Answer 6

• assess all or none response: what percentage responds at a given dose?
• used to assess relationship btw efficacy and safety
• steep slope=less population variability

Question 7

TD50

Answer 7

dose where 50% of individuals will have a toxic response

Question 8

Therapeutic index

Answer 8

TD50/ED50

margin of safety

Question 9

effect of reversible/irreversible antagonist on dose response curve of given agonist

Answer 9

• reversible: Lower potency, same Emax

- irreversible: lower Emax

Question 10

antisense

Answer 10

• complementary strand of mRNA blocks transcription of DNA
• cancer
• RNAi marks mRNA for destruction
• names end in -sen

Question 11

monoclonal antibodies

Answer 11

• highly specific antagonist, or bind ligand
• inflammatory disorders (chron’s), neurological disorders (MS), visual (mac degen), cancer
• names end in -mab

Question 12

fusion proteins

Answer 12

• receptor fused to antibody, binds ligans and prevents it binding real receptor
• inflammatory disorders
• names end -cept

Question 13

aptamers

Answer 13

• oligonucleotides that bind target protein, prevet receptor interaction
• cancer, viruses
• names include -apt-

Question 14

tolerance

Answer 14

reduction in response over time

• receptor downregulation: fewer on cell surface
• desensitiaion: receptors less responsive (attenuated signalling)
• Tachyphylaxis: tolerace develops rapidly (min-hrs) due to desensitizaion

Question 15

Rebound

Answer 15

• receptor upregulation can occur with chronic use of antagonist
• stop meds=exaggerated opposite response
• prevent by weaning off meds slowly

Question 16

Law of Mass action

Answer 16

More drugs means more binding means greater response

Question 17

spare receptors

Answer 17

receptors that are not bound when maximal response achieved

Question 18

side effects

Answer 18

• effect continues longer
• receptor at unwanted region
• lack of sensitivity

-dose is main determinant