/I2025IUpdate)IAdvancedI
PharmacotherapeuticsICompleteIGuideI|QsI
&IAs|I100%ICorrect|IGradeIAI(VerifiedI
Answers)
Q:IExplainIfirstIpassImetabolism
Answer:
muchIofItheIdrugIisIlostIinItheIabsorptionIprocess.ITheIliverImetabolizesImanyIdrugs,IthusIred
ucesItheIbio-availabilityIofItheIdrug.
Q:IWhatIisItheIfastedIrouteIofIabsorption:
Answer:
TheIfastestIrouteIofIabsorptionIisIinhalation,IandInotIasImistakenlyIconsideredItheIIVIadminist
ration.
Q:IWhyIdoesItheIGIItractItakeIlongerItoIabsorb?
Answer:
TheIGIItractIisIlinedIwithIepithelialIcells;IdrugsImustIpermeateIthroughItheseIcellsIinIorderItoI
beIabsorbedIintoItheIcirculatoryIsystem.
Q:IWhatIisIOneIparticularIcellularIbarrierIthatImayIpreventIabsorptionIofIaIgivenIdrug?
,Answer:
theIcellImembrane.ICellImembranesIareIessentiallyIlipidIbilayersIwhichIformIaIsemipermeable
Imembrane.IPureIlipidIbilayersIareIgenerallyIpermeableIonlyItoIsmallIandIunchargedIsolutes,Ih
enceIwhetherIorInotIaImoleculeIisIionizedIwillIaffectIitsIabsorption,IsinceIionicImoleculesIareI
charged.
Q:IWhatIisIsolubility?
Answer:
SolubilityIfavorsIchargedIspecies,IpermeabilityIfavorsIneutralIspecies.ISomeImoleculesIhaveIsp
ecialIexchangeIproteinsIandIchannelsItoIfacilitateImovementIfromItheIlumenIintoItheIcirculatio
n.
Q:IWhyIdoesIabsorptionIoccurIatIaIslowerIrateIforIoral,IIM,ISQIroutes?
Answer:
AbsorptionIoccursIatIaIslowerIrateIbecauseItheIcomplexImembraneIsystemsIofIGIImucosalIlay
ers,Imuscle,IandIskinIdelayIdrugIpassage.
Q:ITheIabilityIofIaIdrugItoIcrossIaIcellImembraneIdependsIon:
Answer:
whetherItheIdrugIisIwaterIorIlipidI(fat)Isoluble.ILipid-
solubleIdrugsIeasilyIcrossIthroughIcellImembranes;Iwater-solubleIdrugsIcan't.ILipid-
solubleIdrugsIcanIalsoIcrossItheIblood-brainIbarrierIandIenterItheIbrain.
Q:IAsIaIdrugItravelsIthroughItheIbody,IitIcomesIinIcontactIwith?
Answer:
,proteinsIsuchIasItheIplasmaIproteinIalbumin.ITheIdrugIcanIremainIfreeIorIbindItoItheIprotein.I
TheIportionIofIaIdrugIthat'sIboundItoIaIproteinIisIinactiveIandIcan'tIexertIaItherapeuticIeffect.I
OnlyItheIfree,IorIunbound,IportionIremainsIactive.IAIdrugIisIsaidItoIbeIhighlyIprotein-
boundIifImoreIthanI80%IofItheIdrugIisIboundItoIprotein.
Q:IIdentifyIdrugImetabolismIandItheIroleIofIisoenzymesIinItheIp450Isystem
Answer:
CYPsIareItheIareItheImajorIenzymesIinvolvedIinIdrugImetabolismIaccountingIforIaboutI75%Io
fItheItotalImetabolism.
Q:INaturallyIoccurringIcompoundsImayIinduceIorIinhibitICYPIactivity.
Answer:
ForIexample,IbioactiveIcompoundsIfoundIinIgrapefruitIjuiceIandIsomeIotherIfruitIjuicesIinclud
ingIdihydroxyIforgottenIandIparasitinIAIhaveIbeenIfoundItoIinhibitICYP3a4ImediatedImetabol
ismIofIcertainImedicationsIleadingItoIincreasedIbioavailabilityIandItheIstrongIpossibilityIofIov
erdosing.
Q:IWhatIdoesIgrapefruitIhaveItoIdoIwithICYP?
Answer:
GrapefruitIisIanIinhibitorIandIwillIdecreaseItheImetabolismIofIdrugsIbyItheIcypIenzymes
Q:IWhenI2IdrugsIareIbothImetabolizedIbyItheIp450IsystemItheIdrugIshouldIbe
Answer:
, administeredIatIseparateItimesItoIpreventItheImetabolismIofIoneIdrugIresultingIinItoxicIeffects
IofItheIotherIdrug.I(becauseIitIwouldIhaveIlessIproteinItoIbindItoo,IthusImoreIfreeIfloatingIdru
g)
Q:IWhatIisItheIefficacyIofIaIdrug?
Answer:
EfficacyIisItheImaximumIresponseIachievableIfromIaIdrug.IEffectivenessIrefersItoItheIabilityIo
fItheIdrugItoIproduceIaIbeneficialIeffect.
Q:IOnItheIdrugIconcentrationIcurveIwhatIisItheIfirstIsignIofIaItherapeuticIeffect?
Answer:
TheIonsetIofIaction
Q:IWhatIisItheIpurposeIofIaIpeakIandItroughIlevel?
Answer:
ToIdetermineIifItheIdrugIisIinItherapeuticIrange.
Q:IDescribeItheIpurposeIofIbloodIbrainIbarrier
Answer:
TheIBBBIisIaIhighlyIselectiveIpermeabilityIbarrierIthatIseparatesItheIcirculatingIbloodIfromIth
eIbrainIandIextracellularIfluidIinItheICNS.ITheIBBBIisIformedIbyIbrainIendothelialIcellsIwhic
hIareIconnectedIbyItightIjunctionsIwithIanIextremelyIhighIelectricalIresistivityIofIatIleastI0.1I
micron.ITheIBBBIallowsItheIpassageIofIwater,IsomeIgases,IandIlipidIsolubleImoleculesIbyIpas
siveIdiffusionIasIwellIasItheIselectiveItransportImoleculesIsuchIasIglucoseIandIaminoIacidsItha
tIareIcrucialItoIneuroIfunction.