B:Uses:l.Hypotension:2.Earlyphaseofneurogenicshock3.Uppergastrointestinaltractbleeding:It contracts blood vessels of esophagus and stomachand stopsthebleeding
B:Uses: 1.Hypotension: 2.Early phase of neurogenic shock 3.Upper gastrointestinal tract bleeding: It contracts blood vessels of esophagus and stomach, and stops the bleeding
III.β ReceptorAgonists-Isoprenaline(Isoproterenol)PharmacologicaleffectsL.Cardiovascularsystemβ, receptors :increases cardiac contractility,cardiacoutput,heartrate,and conductance.β, receptors :decrease theblood pressureSystolic blood pressure rise,diastolic pressure falls
A. Pharmacological effects 1.Cardiovascularsystem- β1 receptors : increases cardiac contractility, cardiac output, heart rate, and conductance. β2 receptors :decrease the blood pressure Systolic blood pressure rise, diastolic pressure falls. III. Receptor Agonists -Isoprenaline (Isoproterenol)
Isoproterenolcausesvasodilation,but stronglyincreasescardiacforceandrate.InfusionsoprotoreO(anuwed)Oean00888nae6HU)HignsseaO15mminttesTmeisoproterenoORLSRSSIignificantdecreaseaperiphorairesitanceIsoproterenoicausesmarkediydecreasedwithdiastolicpressure,increasedmoderateiysystolicpressure
2.Bronchial smoothmuusclebronchodilation3.Metabolism:increaseglycogenolysis,increased lipolysis.increases oxygen consumption
2.Bronchialsmooth musclebronchodilation 3.Metabolism: increase glycogenolysis, increased lipolysis, increases oxygen consumption
10.1TABLECardiovascularEffectsofCatecholaminesinHumans(intherapeuticdosesof0.1-0.4μg/kg/minlVor0.5-1.0mgsc)CardiovascularfunctionEpinephrineNorepinephrineIsoproterenolSystolicblood pressure0++++++Diastolic blood pressure++Mean blood pressure+0-++Total peripheralresistance++++Heart rate (chronotropic effect)++Stroke output (inotropic effect)+++++-0Cardiac output++++++Key:O=no cffect:+= increased:-=decreased.The number of symbols indicates the approximate magnitude of the responseTABLE10.2ResponseoftheMajorVascularBedstoUsualDosesoftheCatecholaminesVascular bedReceptortype*NorepinephrineEpinephrineIsoproterenolNoneCutaneous blood vesselsConstrictionConstrictionaNone (weak dilation)Visceral blood vesselsConstrictionConstrictionαRenal blood vesselsConstrictionConstrictionNone (weak dilation)aDilationDilationDilationCoronary bloodvesselsa,βDilationSkeletal muscleblood vesselsConstrictionDilationa, β2Pial blood vesselsDilationConstriction/dilationConstriction/dilationa,β$While virtually all blood vessels have a-receptors, some also have Q,-receptors Stimulation of either subtype generally results in vasocon-striction
B.Usesl.Cardiac arrest and heart block:2.Asthma:nowitlargelyhasreplacedbyotherbeensympathomimetics.Terbutaline3.Shock:
B. Uses 1.Cardiac arrest and heart block: 2.Asthma: now it largely has been replaced by other sympathomimetics. Terbutaline 3.Shock:
IV.Dopamine Receptor AgonistsDopaminePharmacological EffectsDopamineactivatesDA receptor,β,and a,receptors.l.heart:Increase of cardiaccontractility2.bloodvessels:In low dose:stimulationD,receptordilation of renaland mesentericbloodvessels
A. Pharmacological Effects Dopamine activates DA receptor, β1 and α1 receptors. 1.heart: Increase of cardiac contractility 2.blood vessels: In low dose: stimulation D1 receptor dilation of renal and mesenteric blood vessels. IV. Dopamine Receptor Agonists -Dopamine
NorcpinephnineDopamineEpinephnineIsoproterenol11100r(unu)-1500/111-1---1180(150u1209060L10 μg/min0.5mg/min10 μg/min10 μg/minS1-ssi001515015015Time (min)FIGURE 10.4Carcliovasculareffects of infusion of norepinephrine,epinephrine,isoproterenol,and dopamine inhumans.Infusions were made intravenously dluring the time indicated by the broken lines.Heartrate is given in beats per minute,blood pressure in millimeters of mercury,and peripheralresistanceinarterial blood pressure.(ReprintedwithpermissionfromAllwood MJ.CobbaldAFand GinsburgJ.Peripheral vasculareffects ofnoradrenaline,isopropyl-noracrenaline,anddopamine.BrMedBull19:132,1963.ReproducedbypermissionoftheMedicalDepartmentTheBritishCouncil
LargedosageofDA:activatesa, receptorLeading to vasoconstrictionB.Uses:Some types of shock and acute renal insufficiencydiuretics
Large dosage of DA : activates α1 receptor Leading to vasoconstriction. B. Uses : Some types of shock and acute renal insufficiency diuretics
IndirectlyActingAdrenomimeticDrugs--EphedrinePharmacologicalActionsEphedrine increases systolic and diastolic bloodpressure; Contractile force of the heart and cardiacoutput are both increased.Ephedrine producesbronchial smooth muscle relaxation of prolongedduration when administered orally.ClinicalUsesIt is often used prophylacticallyto prevent asthmatieattacks and is used as a nasaldecongestant.as a mydriatic,and in certain allergic disorders
Pharmacological Actions Ephedrine increases systolic and diastolic blood pressure; Contractile force of the heart and cardiac output are both increased. Ephedrine produces bronchial smooth muscle relaxation of prolonged duration when administered orally. Clinical Uses It is often used prophylactically to prevent asthmatic attacks and is used as a nasal decongestant. as a mydriatic, and in certain allergic disorders. Indirectly Acting Adrenomimetic Drugs -Ephedrine