英国纽卡斯尔大学药理学

《英国纽卡斯尔大学药理学》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、BasicpharmacokineticsProfessorFKamaliWolfsonUnitofClinicalPharmacologyBasicpharmacokineticsPharmacokineticsconceptOnecompartmentmodelSemi-logarithmdrugconcentrationvtimeplotMeasurementofdrugpharmacokineticparametersBasicpharmacokineticsPharmacokineticsisadisciplinethatusesmathematicalmode

2、lstodescribeandpredictdrugamountsandconcentrationsinvariousbodyfluidsthatchangesinthesequantitiesovertime.Absorption,distribution,biotransformationandelimination.Plasmadrugconcentration:-netresultsoftheaboveprocessestakingplacesimultaneously.Whatispharmacokinetics?Whatisthevalueofpharmaco

3、kinetics?Establishandmaintaintherapeutic,yetnon-toxicamountsofdruginbodyandatthepharmacologicsiteofaction.Morespecifically:Rationalchoiceofdrugdoses,frequencyofadministration,androuteofadministration.CharacteristicsofthepatientandhisdiseaseCanalterthepharmacokineticpropertiesofadrugAdju

4、stmentofdosage,dosingfrequencycancompensateforkineticchangesProblemsofineffectivenessand/ortoxicitymaybeavoided.Theunderstandingofpharmacokineticsshouldenhancethelikelihoodofsafeandeffectivedrugtherapy.FactorsaffectingdrugpharmacokineticsPatientcharacteristics:AgeSexTotalbodyweightSmoking

5、habitsAlcoholconsumptionOtherco-ingesteddrugsFactorsaffectingdrugpharmacokineticsDiseasestates:Liverdisease(cirrhosis,hepatitis)RenaldiseaseCongestiveheartfailureInfectionFeverShockSevereburnsAnaemiaOnecompartmentmodelDyedoesnotdisappearatasteadyrateRateofeliminationofdyeisproportionaltot

6、heconcentrationAnyprocessinwhichtherateofchangeofavariableisproportionaltothemagnitudeofthatvariableissaidtobeanexponentialprocessSemi-logarithmplotAKelof0.1/himplies10%ofdrugeliminatedperhour.-Kel=slope=1nC1-1nC2/tRewrite1nC1–1nC2as:1n(C1/C2)Whentimeintervalt=t½;C1/C2=2As1n2=0.693Kel=0.6

7、93t½Semi-logarithmplotSemi-logarithmplotCalculationofdrughalf-life(t½)Calculationofeliminationconstant(Kel)TwomethodsGradientmethod2.EquationKel=0.7(time)-1t½abSlope=a/bEliminationclearance(CL)ClearanceusedasameasureofeliminationAppliestobothexcretionandmetabolismMo