NR 565 week 1 notes
i i i i
Agonist- ia idrug ithat ibinds ito iand iactivates ia ireceptor. iCan ibe ifull, ipartial ior iinverse. iA ifull iagonist
ihas ihigh iefficacy, iproducing ia ifull iresponse iwhile ioccupying ia irelatively ilow iproportion iof
ireceptors. iA ipartial iagonist ihas ilower iefficacy ithan ia ifull iagonist. iIt iproduces isub-maximal
iactivation ieven iwhen ioccupying ithe itotal ireceptor ipopulation, itherefore icannot iproduce ithe
imaximal iresponse, iirrespective iof ithe iconcentration iapplied. iAn iinverse iagonist iproduces ian
ieffect iopposite ito ithat iof ian iagonist, iyet iit ibinds ito ithe isame ireceptor ibinding-site ias ian iagonist.
Antagonist- ia idrug ithat iattenuates ithe ieffect iof ian iagonist. iCan ibe icompetitive ior inon-
icompetitive, ieach iof iwhich ican ibe ireversible ior iirreversible. iA icompetitive iantagonist ibinds ito ithe
isame isite ias ithe iagonist ibut idoes inot iactivate iit, ithus iblocks ithe iagonist’s iaction. iA inon-
icompetitive iantagonist ibinds ito ian iallosteric i(non-agonist) isite ion ithe ireceptor ito iprevent
iactivation iof ithe ireceptor. iA ireversible iantagonist ibinds inon-covalently ito ithe ireceptor,
itherefore ican ibe i“washed iout”. iAn iirreversible iantagonist ibinds icovalently ito ithe ireceptor iand
icannot ibe idisplaced iby ieither icompeting iligands ior iwashing.
B iMax- iThe imaximum iamount iof idrug ior iradioligand, iusually iexpressed ias ipicomoles i(pM) iperimg
iprotein, iwhich ican ibind ispecifically ito ithe ireceptors iin ia imembrane ipreparation. iCan ibe iused ito
imeasure ithe idensity iof ithe ireceptor isite iin ia iparticular ipreparation.
Desensitization- iA ireduction iin iresponse ito ian iagonist iwhile iit iis icontinuously ipresent iat ithe
ireceptor, ior iprogressive idecrease iin iresponse iupon irepeated iexposure ito ian iagonist.
Duration iof iaction- iThe iduration iof iaction iof ia idrug iis ithe ilength iof itime ithat iparticular idrug iis
ieffective. iDuration iof iaction iis ia ifunction iof iseveral iparameters iincluding iplasma ihalf-life, ithe
itime ito iequilibrate ibetween iplasma iand itarget icompartments, iand ithe ioff irate iof ithe idrug ifromiits
ibiological i target.
Efficacy- iDescribes ithe iway ithat iagonists ivary iin ithe iresponse ithey iproduce iwhen ithey ioccupyithe
isame inumber iof ireceptors. iHigh iefficacy iagonists iproduce itheir imaximal iresponse iwhile
ioccupying ia irelatively ilow iproportion iof ithe itotal ireceptor ipopulation. iLower iefficacy iagonists ido
inot iactivate ireceptors ito ithe isame idegree iand imay inot ibe iable ito iproduce ithe imaximal
iresponse.
Half-life- iHalf-life i(t½) iis ian iimportant ipharmacokinetic imeasurement. iThe imetabolic ihalf-life iof ia
idrug iin ivivo iis ithe itime itaken ifor iits iconcentration iin iplasma ito idecline ito ihalf iits ioriginal ilevel.
iHalf-life irefers ito ithe iduration iof iaction iof ia idrug iand idepends iupon ihow iquickly ithe idrug iis
ieliminated ifrom ithe iplasma. iThe iclearance iand idistribution iof ia idrug ifrom ithe iplasma iare
itherefore iimportant iparameters ifor ithe idetermination iof iits ihalf-life.
Mechanism iof iaction i(MOA)- iRefers ito ithe ispecific ibiochemical iinteraction ithrough iwhich iaidrug
isubstance iproduces iits ipharmacological ieffect.
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, • Receptor iinteractions-occur ithat ithe icell ireceptor isite, iusually ia iprotein istructure iwithin
ithe icell imembrane. iReceptor isites ivary ias ito ithe isubstances ithey iattract iand ithe idegreeito
iwhich ithey iattract ithem.
o Ex: icalcium ichannel iblockers iblock ithe iflow iof icalcium iat ithe ireceptor isite
ileading ito ia ireduction iin imuscle icontraction=decreased iBP
• Enzyme iinteractions-enzymes iare icatalysts; idrugs ican ienhance ior iinhibit ithe icatalytic
iactions iof ithese ienzymes, ithe idegree ito iwhich ithis ihappens iaffects iboth ithe idrugs
action iand ithe itie irequired ifor iits ielimination
o Grapefruit ijuice iand istatins-juice iinterferes iwith ia iliver imetabolic ienzyme
ipreventing ithe iproper ibreak idown iof istatins-rhabdo
• Nonselective iinteractions- idrugs ichemically ialter ior iphysically iinterfere iwith icellular
istructures ior itheir iprocesses
o Ex: ichemotherapy-attacks iall irapidly iproliferating icells i(cancerous iand inon-
icancerous)
Potency- iA imeasure iof ithe iconcentrations iof ia idrug iat iwhich iit iis ieffective.
Silent iAntagonist- iA idrug ithat iattenuates ithe ieffects iof iagonists ior iinverse iagonists, iproducing ia
ifunctional ireduction iin isignal itransduction. iAffects ionly iligand-dependent ireceptor iactivation
iand idisplays ino iintrinsic iactivity iitself. iAlso iknown ias ia ineutral iantagonist.
Therapeutic iwindow- iThe itherapeutic iwindow iis ithe iamount iof ia imedication ibetween ithe
iamount ithat igives ian ieffect i(effective idose) iand ithe iamount ithat igives imore iadverse ieffects ithan
idesired ieffects. iFor iinstance, imedication iwith ia ismall ipharmaceutical iwindow imust ibe
iadministered iwith icare iand icontrol, ie.g. iby ifrequently imeasuring iblood iconcentration iof itheidrug,
isince iit ieasily iloses ieffects ior igives iadverse ieffects.
Pharmacodynamics- ithe inature iand iintensity iof ithe iresponse ithat ithe idrug ihas ion ithe ibody
Pharmacokinetics-the istudy iof ithe iway ithe ibody ideals iwith ithe iabsorption, idistribution,
imetabolism, iand iexcretion iof idrugs. iThe istudy iof iwhat ihappens ito ia idrug ifrom ithe itime iof
iadministration iuntil ithe iparent idrug iand iall imetabolites ileave ithe ibody.
• Time iframe:
• onset iof iaction-how ilong ibefore ithe imedication ifirst ibegins ito iaffect ithe ipatient
• time ito ipeak ieffect-how ilong ibefore ithe imedication iis iat ithe iheight iof iits ieffect
• duration iof iaction-how ilong ithe itherapeutic ieffects ilasts
• half-life-the itime irequired ifor ihalf iof ia ichemical ito ibe ieliminated ifrom ithe ibody
o drug iis iusually iconsidered ieffectively ieliminated iafter iabout i5 ihalf ilives
o the ilength iof ithe idrug ihalf-life idetermines ihow ilong iit itakes ito ireach isteady
istate.
o drug iabsorption
o drug iremoval
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i i i i
Agonist- ia idrug ithat ibinds ito iand iactivates ia ireceptor. iCan ibe ifull, ipartial ior iinverse. iA ifull iagonist
ihas ihigh iefficacy, iproducing ia ifull iresponse iwhile ioccupying ia irelatively ilow iproportion iof
ireceptors. iA ipartial iagonist ihas ilower iefficacy ithan ia ifull iagonist. iIt iproduces isub-maximal
iactivation ieven iwhen ioccupying ithe itotal ireceptor ipopulation, itherefore icannot iproduce ithe
imaximal iresponse, iirrespective iof ithe iconcentration iapplied. iAn iinverse iagonist iproduces ian
ieffect iopposite ito ithat iof ian iagonist, iyet iit ibinds ito ithe isame ireceptor ibinding-site ias ian iagonist.
Antagonist- ia idrug ithat iattenuates ithe ieffect iof ian iagonist. iCan ibe icompetitive ior inon-
icompetitive, ieach iof iwhich ican ibe ireversible ior iirreversible. iA icompetitive iantagonist ibinds ito ithe
isame isite ias ithe iagonist ibut idoes inot iactivate iit, ithus iblocks ithe iagonist’s iaction. iA inon-
icompetitive iantagonist ibinds ito ian iallosteric i(non-agonist) isite ion ithe ireceptor ito iprevent
iactivation iof ithe ireceptor. iA ireversible iantagonist ibinds inon-covalently ito ithe ireceptor,
itherefore ican ibe i“washed iout”. iAn iirreversible iantagonist ibinds icovalently ito ithe ireceptor iand
icannot ibe idisplaced iby ieither icompeting iligands ior iwashing.
B iMax- iThe imaximum iamount iof idrug ior iradioligand, iusually iexpressed ias ipicomoles i(pM) iperimg
iprotein, iwhich ican ibind ispecifically ito ithe ireceptors iin ia imembrane ipreparation. iCan ibe iused ito
imeasure ithe idensity iof ithe ireceptor isite iin ia iparticular ipreparation.
Desensitization- iA ireduction iin iresponse ito ian iagonist iwhile iit iis icontinuously ipresent iat ithe
ireceptor, ior iprogressive idecrease iin iresponse iupon irepeated iexposure ito ian iagonist.
Duration iof iaction- iThe iduration iof iaction iof ia idrug iis ithe ilength iof itime ithat iparticular idrug iis
ieffective. iDuration iof iaction iis ia ifunction iof iseveral iparameters iincluding iplasma ihalf-life, ithe
itime ito iequilibrate ibetween iplasma iand itarget icompartments, iand ithe ioff irate iof ithe idrug ifromiits
ibiological i target.
Efficacy- iDescribes ithe iway ithat iagonists ivary iin ithe iresponse ithey iproduce iwhen ithey ioccupyithe
isame inumber iof ireceptors. iHigh iefficacy iagonists iproduce itheir imaximal iresponse iwhile
ioccupying ia irelatively ilow iproportion iof ithe itotal ireceptor ipopulation. iLower iefficacy iagonists ido
inot iactivate ireceptors ito ithe isame idegree iand imay inot ibe iable ito iproduce ithe imaximal
iresponse.
Half-life- iHalf-life i(t½) iis ian iimportant ipharmacokinetic imeasurement. iThe imetabolic ihalf-life iof ia
idrug iin ivivo iis ithe itime itaken ifor iits iconcentration iin iplasma ito idecline ito ihalf iits ioriginal ilevel.
iHalf-life irefers ito ithe iduration iof iaction iof ia idrug iand idepends iupon ihow iquickly ithe idrug iis
ieliminated ifrom ithe iplasma. iThe iclearance iand idistribution iof ia idrug ifrom ithe iplasma iare
itherefore iimportant iparameters ifor ithe idetermination iof iits ihalf-life.
Mechanism iof iaction i(MOA)- iRefers ito ithe ispecific ibiochemical iinteraction ithrough iwhich iaidrug
isubstance iproduces iits ipharmacological ieffect.
This istudy isource iwas idownloaded iby i100000823822032 ifrom iCourseHero.com ion i12-20-2021 i21:13:50 iGMT i-
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, • Receptor iinteractions-occur ithat ithe icell ireceptor isite, iusually ia iprotein istructure iwithin
ithe icell imembrane. iReceptor isites ivary ias ito ithe isubstances ithey iattract iand ithe idegreeito
iwhich ithey iattract ithem.
o Ex: icalcium ichannel iblockers iblock ithe iflow iof icalcium iat ithe ireceptor isite
ileading ito ia ireduction iin imuscle icontraction=decreased iBP
• Enzyme iinteractions-enzymes iare icatalysts; idrugs ican ienhance ior iinhibit ithe icatalytic
iactions iof ithese ienzymes, ithe idegree ito iwhich ithis ihappens iaffects iboth ithe idrugs
action iand ithe itie irequired ifor iits ielimination
o Grapefruit ijuice iand istatins-juice iinterferes iwith ia iliver imetabolic ienzyme
ipreventing ithe iproper ibreak idown iof istatins-rhabdo
• Nonselective iinteractions- idrugs ichemically ialter ior iphysically iinterfere iwith icellular
istructures ior itheir iprocesses
o Ex: ichemotherapy-attacks iall irapidly iproliferating icells i(cancerous iand inon-
icancerous)
Potency- iA imeasure iof ithe iconcentrations iof ia idrug iat iwhich iit iis ieffective.
Silent iAntagonist- iA idrug ithat iattenuates ithe ieffects iof iagonists ior iinverse iagonists, iproducing ia
ifunctional ireduction iin isignal itransduction. iAffects ionly iligand-dependent ireceptor iactivation
iand idisplays ino iintrinsic iactivity iitself. iAlso iknown ias ia ineutral iantagonist.
Therapeutic iwindow- iThe itherapeutic iwindow iis ithe iamount iof ia imedication ibetween ithe
iamount ithat igives ian ieffect i(effective idose) iand ithe iamount ithat igives imore iadverse ieffects ithan
idesired ieffects. iFor iinstance, imedication iwith ia ismall ipharmaceutical iwindow imust ibe
iadministered iwith icare iand icontrol, ie.g. iby ifrequently imeasuring iblood iconcentration iof itheidrug,
isince iit ieasily iloses ieffects ior igives iadverse ieffects.
Pharmacodynamics- ithe inature iand iintensity iof ithe iresponse ithat ithe idrug ihas ion ithe ibody
Pharmacokinetics-the istudy iof ithe iway ithe ibody ideals iwith ithe iabsorption, idistribution,
imetabolism, iand iexcretion iof idrugs. iThe istudy iof iwhat ihappens ito ia idrug ifrom ithe itime iof
iadministration iuntil ithe iparent idrug iand iall imetabolites ileave ithe ibody.
• Time iframe:
• onset iof iaction-how ilong ibefore ithe imedication ifirst ibegins ito iaffect ithe ipatient
• time ito ipeak ieffect-how ilong ibefore ithe imedication iis iat ithe iheight iof iits ieffect
• duration iof iaction-how ilong ithe itherapeutic ieffects ilasts
• half-life-the itime irequired ifor ihalf iof ia ichemical ito ibe ieliminated ifrom ithe ibody
o drug iis iusually iconsidered ieffectively ieliminated iafter iabout i5 ihalf ilives
o the ilength iof ithe idrug ihalf-life idetermines ihow ilong iit itakes ito ireach isteady
istate.
o drug iabsorption
o drug iremoval
This istudy isource iwas idownloaded iby i100000823822032 ifrom iCourseHero.com ion i12-20-2021 i21:13:50 iGMT i-
06:00
https://www.coursehero.com/file/78307152/NR-565-week-1-notesdocx/
