Pharmacodynamics

Question 1

how do most drugs produce their effect

Answer 1

by binding to protein molecules

Question 2

what is the only important exception to protein being the receptor for drugs

Answer 2

DNA (sometimes drugs bind to it)

Question 3

two types of ion channels

Answer 3

voltage gated channels and ligand gated ion channel

Question 4

describe voltage gated ion channel

Answer 4

conductance is regulated by changes in the membrane potential

Question 5

describe ligand gated ion channel

Answer 5

conductance is regulated by ligands such as GABA, Ca2+, and etc binding to the channel

Question 6

example of voltage gated ion channel drug and how it works

Answer 6

local anesthetics which block voltage gated sodium channels from transmitting pain information from the periphery to the CNS

Question 7

example of ligand gated ion channel drug

Answer 7

benzos which bind to GABA receptors thereby enhancing the ability of GABA to open chloride channels

Question 8

what does cAMP hormone mediate

Answer 8

• mobilization of stored energy
• increases rate and contraction force of the heart muscle
• relaxation of smooth muscle

Question 9

what degrades cAMP and what is cAMP degraded to

Answer 9

cAMP is degrades to 5’AMP by phosphodiesterases (PDE)

Question 10

big difference between IP3 and DAG

Answer 10

IP3 releases Ca from ER while DAG alongside Ca activates protein kinase C (PKC)

Question 11

examples of ligand regulated transmembrane enzyme

Answer 11

tyrosine kinase, serine/threonine kinase, guanylyl cyclase

Question 12

examples of tyrosine kinases

Answer 12

insulin receptor, epidermal growth factor receptor (EGFR), platelet derived growth factor (PDGFR), nerve growth factor receptor (NGFR)

Question 13

what do cytokine receptors respond to

Answer 13

growth hormone, prolactin, erythropoietin, and interferons

PIGE

Question 14

what does the cytokine receptor bind to

Answer 14

intracellular tyrosine kinase, from the Janus-kinase (JAK) family

Question 15

JAK then phosphorylates another set of proteins referred to as

Answer 15

STAT (signal transducers and activators of transcription) –> pathway is referred to as JAK/STAT pathway

Question 16

what are statins

Answer 16

competitive inhibitors of HMG-CoA reductase, the enzyme that catalyzes the first step of cholesterol biosynthesis

Question 17

what is the result/effect of using statin

Answer 17

it decreases intracellular cholesterol hence causing an up-regulation of LDL receptors in hepatocytes (in order to increase the intracellular cholesterol) and this leads to increased clearance of LDL from the blood

Question 18

what are structural proteins

Answer 18

structures such as tubulin that are important targets for anti neoplastic drugs

Question 19

what type of drugs cause irreversible competitive antagonism

Answer 19

those that have reactive groups hence can form covalent bonds with the receptors

Question 20

examples of drugs that are irreversible competitive antagonist

Answer 20

• phenoxybenzamine (alpha adrenoreceptor blocker)

- aspirin, omeprazole, MAO inhibitors which are irreversible enzyme inhibitors

Question 21

effect of a drug gradually diminishing when giving continuously or repeatedly and occurs within course of few minutes is described as

Answer 21

desensitization or tachyphylaxis

Question 22

gradual decrease in responsiveness to a drug and taking days to weeks to develop is described as

Answer 22

tolerance

Question 23

loss of therapeutic efficacy

Answer 23

refractoriness