Pharmacodynamics 1

Question 1

pharmacodynamics: study of what 3 things

Answer 1

what drugs do to the body, mechanisms of action, quantification of drug responses

Question 2

how do drugs elicit effects in the body

Answer 2

drugs interact with target macromolecules - modify physiological or biochemical events

Question 3

7 potential drug targets

Answer 3

regulatory proteins in cell membranes (Receptors, channels, transporters). intracellular proteins. nuclear receptors. RNA/DNA. small molecules. nonspecific physical/chemical targets. non human targets

Question 4

membrane receptors as drug targets: usually have a? response initiated when?

Answer 4

have a natural endogenous activator aka a ligand: neurotransmitter, hormone or autacoid. Response is initiated when receptor activated

Question 5

membrane receptors as drug targets: two consequences of drug binding?

Answer 5

agonist = initiation of response. antagonist = blockade of response.

Question 6

membrane receptors as drug targets: limitation?

Answer 6

receptors present in finite numbers = limitation to maximal possible effect

Question 7

4 major classes of membrane receptors + examples

Answer 7

ligand or voltage gated ion channels (GABA-A, Na channels. GPCRs (B-adrenoreceptors). nuclear hormone receptors (estrogen). catalytic receptors (Receptor tyrosine kinases for insulin).

Question 8

opioid receptors: 3 types? activated by? 3 classical agonists?

Answer 8

mu, kappa, delta: activated by endogenous peptides called enkephalins. morphine, fentanyl. codeine

Question 9

opioid receptors: 4 effects

Answer 9

u, k, d = analgesia. u/d = euphoria and dependence. u = respiratory depression. u = GI motility.

Question 10

adverse effects of opioid receptor agonists (5)

Answer 10

stimulates histamine release = itch. severe respiratory depression. constipation, urinary retention, anti-tussive (suppresses cough), vomiting.

Question 11

W18

Answer 11

more potent than fentanyl but actually don’t act at opioid receptors

Question 12

chemical antagonism + 2 examples

Answer 12

one drug inactivates another to reduce its effects: Ca carbonate neutralizes gastric H+, EDTA binds Ca2+ in chelation therapy

Question 13

physiological antagonism + example

Answer 13

one drug exerts its actions to oppose another: works via distinct sites + mechanisms. adrenaline for allergic bronchoconstriction.

Question 14

antibodies as receptor blockers: example for blood clots?

Answer 14

abciximab binds to glycoprotein IIb/IIIa receptors on platelets = prevents platelet aggregation + thrombosis, useful with angioplasty to prevent restenosis

Question 15

antibodies as agonist inactivators: how do they work?

Answer 15

bind and inactivate the endogenous agonist

Question 16

TNF-a: what? key component of? causes? inactivated by? treatment?

Answer 16

endogenous chemical aka cytokine, key component of autoimmune reaction, causes inflammation. bound/inactivated by anti-TNF antibodies like infliximab, useful to treat inflammatory conditions like Crohn’s or rheumatoid arthritis

Question 17

drugs can potentiate agonist actions in what ways?

Answer 17

allosteric mechanism to enhance receptor affinity. inhibit agonist inactivation

Question 18

example of allosteric potentiation of agonist actions? (for GABA)

Answer 18

benzodiazepines enhance GABA-mediated neural inhibition.

Question 19

benzodiazepine effects: sequence + 3 other effects?

Answer 19

dose-related: anti-anxiety, sedation, hypnosis, coma, resp depression/death. other effects: skeletal muscle relaxation, anti-convulsant, tolerance and dependence.

Question 20

benzodiazepine antagonist

Answer 20

flumanezil