Pharmacodynamics Flashcards
how do most drugs produce their effect
by binding to protein molecules
what is the only important exception to protein being the receptor for drugs
DNA (sometimes drugs bind to it)
two types of ion channels
voltage gated channels and ligand gated ion channel
describe voltage gated ion channel
conductance is regulated by changes in the membrane potential
describe ligand gated ion channel
conductance is regulated by ligands such as GABA, Ca2+, and etc binding to the channel
example of voltage gated ion channel drug and how it works
local anesthetics which block voltage gated sodium channels from transmitting pain information from the periphery to the CNS
example of ligand gated ion channel drug
benzos which bind to GABA receptors thereby enhancing the ability of GABA to open chloride channels
what does cAMP hormone mediate
- mobilization of stored energy
- increases rate and contraction force of the heart muscle
- relaxation of smooth muscle
what degrades cAMP and what is cAMP degraded to
cAMP is degrades to 5’AMP by phosphodiesterases (PDE)
big difference between IP3 and DAG
IP3 releases Ca from ER while DAG alongside Ca activates protein kinase C (PKC)
examples of ligand regulated transmembrane enzyme
tyrosine kinase, serine/threonine kinase, guanylyl cyclase
examples of tyrosine kinases
insulin receptor, epidermal growth factor receptor (EGFR), platelet derived growth factor (PDGFR), nerve growth factor receptor (NGFR)
what do cytokine receptors respond to
growth hormone, prolactin, erythropoietin, and interferons
PIGE
what does the cytokine receptor bind to
intracellular tyrosine kinase, from the Janus-kinase (JAK) family
JAK then phosphorylates another set of proteins referred to as
STAT (signal transducers and activators of transcription) –> pathway is referred to as JAK/STAT pathway
what are statins
competitive inhibitors of HMG-CoA reductase, the enzyme that catalyzes the first step of cholesterol biosynthesis
what is the result/effect of using statin
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
what are structural proteins
structures such as tubulin that are important targets for anti neoplastic drugs
what type of drugs cause irreversible competitive antagonism
those that have reactive groups hence can form covalent bonds with the receptors
examples of drugs that are irreversible competitive antagonist
- phenoxybenzamine (alpha adrenoreceptor blocker)
- aspirin, omeprazole, MAO inhibitors which are irreversible enzyme inhibitors
effect of a drug gradually diminishing when giving continuously or repeatedly and occurs within course of few minutes is described as
desensitization or tachyphylaxis
gradual decrease in responsiveness to a drug and taking days to weeks to develop is described as
tolerance
loss of therapeutic efficacy
refractoriness
