FactorsthatAffectDrugs’Effectiveness

DepartmentofPharmacology,SchoolofPharmacy,LiaoningUniversityofTraditionalChineseMedicine

Drugs’factors

IDose,andPhysicalnatureofdrugsForinstance,drugpowdersize,formulation,electricalcharge,andshape.劑量不同，同一藥物對(duì)機(jī)體作用的強(qiáng)度也不一樣。例：注射劑、片劑不同劑型吸收程度不同，同一劑型也因制劑工藝不同而不同.Routesofadministration口服:吸收慢而不規(guī)則；注射:不方便、經(jīng)濟(jì)與安全；舌下與直腸：無(wú)首過(guò)效應(yīng),但吸收率不高；吸入：適用于麻醉藥和氣管擴(kuò)張藥局部用藥Suddencardiacdeathparallelsthoseofhypertension,heartmuscleischemia,angina,andheartattack-a70%greaterriskbetweenthehoursof7a.m.and9a.m.,comparedtotherestoftheday.Cushing'ssyndrome(hypercortisolism)causedbyhypothalamusproducingcorticotropin-releasinghormone(CRH),CRHstimulatesthepituitaryreleaseofadrenocorticotropichormone(ACTH)whichstimulatestheadrenalglandstoproducecortisol聯(lián)合用藥

藥物相互作用(Druginteraction)

DrugplasmaproteinbindingSynergism(potentiation)Forinstance,sulfamethoxazoleandtrimethoprimusedincombination.藥物配伍禁忌藥物在體內(nèi)的相互作用包括藥動(dòng)學(xué)和藥效學(xué)兩個(gè)方面。

1、藥動(dòng)學(xué)方面（1）妨礙吸收（2）競(jìng)爭(zhēng)血漿蛋白結(jié)合（3）影響生物轉(zhuǎn)化（4）影響藥物排泄Individualfactors

Individualvariationcanbecongenitaloracquired.I.Age

Children

Childrenareatthestageofdevelopingorgans,sotheabilityofdrughepaticmetabolismandrenalclearanceofchildandarelowerthanthatadult.elderlyForelderly,theorganfunctions,e.g.,liverandkidneydecreased,resultingindrugbiotransformationinliveranddrugexcretioninkidneydeclinedgradually.PharmacologicalandadverseeffectsofadrugforbothchildrenandelderlyareincreasedII.Gender

InPrinciple,therearenoapparentdifferencesbetweenbothgendersresponsetodrugs.However,(a)inmenstruation,drugsaffectinguteruscontractionshouldbeavoidedtopreventfromoverbleeding;(b)inpregnancy,extremecarefulnessshouldbetakenforthesafetyofbothmotherandfetus;and(c)duringlactation,attentionshouldbepaidtosomedrugsthatexcreteviathemilk.III、個(gè)體差異（1）高敏性：對(duì)藥物反應(yīng)特別敏感，很小量就能產(chǎn)生其他人常用量時(shí)的作用。（2）低敏性：對(duì)藥物反應(yīng)特別不敏感，需加大劑量才能有效（3）特異質(zhì)反應(yīng)藥物代謝酶異常：慢乙?；?、快乙?；头撬幬锎x酶異常：藥物吸收障礙、高鐵血紅蛋白缺乏V.Psychologicalfactors

Placeboeffect:(a)Thebeneficialeffectinapatientfollowingaparticulartreatmentthatarisesfromthepatient'sexpectationsconcerningthetreatment(non-specificplaceboeffect)ratherthandrugspecificpharmacologiceffects.Psychologicalfactorsnotonlyincludenon-specificplaceboeffectbutalsoincludePatient-DoctorInteraction(relationship)whichmayinfluencepatient’smoodandothersubjectiveandobjectiveeffectscontrolledbyautonomicnervesandhormones.

VI.Pathologicfactors

Theliveristhemainorganofdrugmetabolism.Hepaticdysfunctiondecreasesdrugmetabolism,drugactionwillbeprolonged.However,somedrugsaretransformedtotheactiveformsintheliver,inthissituation,drugeffectswillbedecreased.

Renalexcretionplaysakeyroleinfinaldrugelimination.Renalfailurewillresultindrugaccumulationinthebody,prolongingitseffect.Cardiacdisease

Cardiacdisease,bylimitingbloodflowtotheliver,maydepresstheeliminationofdrugswhosemetabolismisflow-limitedandtheclearanceisperfusion-limited練習(xí)題聯(lián)合應(yīng)用兩種藥物，其總的作用大于各藥單獨(dú)作用的代數(shù)和，這種作用叫做：A、增強(qiáng)作用B、相加作用C、協(xié)同作用D、互補(bǔ)作用E、拮抗作