بسم الله الرحمن الرحيم
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Transcript of بسم الله الرحمن الرحيم
الرحيم الرحمن الله بسم
AUTONOMIC NS
DRUGS (2)Dr: Samah Gaafar Al-shaygi
ADRENERGIC AGONISTDIRECT ACTING ADRENERGIC AGONIST:1. Epinepherine: Synthesized in the adrenal medulla. At low doses has β vasodilatation effect. At high doses has α vasoconstriction effect. Action:1. CVS: β1 +ve inotropic & chronotropic
effect, COP & O2 demand. 2. Renal: β1 Renin release, blood flow is
decreased.
3. Blood vessels: α1 constrict arterioles to
skin, mucous membranes & viscera. β 2 dilate vessels to liver & muscles.
4. Respiratory: β2 bronchodilataion.5. Hyperglycemia: β2 increases
glycogenolysis & glucagon secretion. α2 decrease release of insulin.
6. Lipolysis.
P.kinetics:Rapid onset & short duration of action.Metabolized by MAO & COMT into
metanephrine & venillymandilic acid.i.m, i.v, s.c, inhalation & endotracheal.
Therapeutic uses:Emergency bronchospasm.choiceAnaphylactic shock.choiceCardiac arrest.Anesthesia.Control bleeding from mucous membranes.
A.E:CNS disturbances.Hemorrage.Cardiac arrythmia.Pulmonary oedema.
NOREPINEPHERINE:Is the neurotransmiter. Therapeuticaaly has α
activity. action:1. CVS:
1. Vasoconistriction.2. Baroreceptor reflex.
2. If atropin is given first it inhibits the vagus so N.e causes tachycardia.
P.kinetics: i.v, poor s.c absorption, short duration of action.
Therapeutic uses:Only in shock.A.E: as epi.+ extravasation.ISOPROTERENOL: β receptors.Action:1. CVS:
Heart: +ve ino & chronotrpic effect. Peripheral vasodilation β2, slight increase in
SBP due to action on heart.
2. pulmonary stopped, metabolic action. Used in cardiac arrest. A.E: as epi. DOPAMINE: High doses α1 Low doses β1 D1, D2 in mesenteric & renal vascular bed
vasodilation.
Action:1. CVS: +ve inotropic & chronotropic effect, vasoconistriction.2. Renal & splanhinic vasodilatation.Therapeutic uses: In cardiogenic & septic shock, hypotension,
severe CCF with oliguria. Metabolized by MAO & COMT to homovanillic
acid. A.E as sympathetic stimulation.
Dobutamine: Selective β1 agonist used to COP in CCF &
inotropic support after cardiac surgery.Phenylepherine:α1 agonist, rasis the BP, reflex bradycardia.Used topically as nasal decongestant & for
ocular mydriasis.Used in SVT.A.E hypertensive headache & arrythmias.
Albuterol & terbutaline:Short acting β2 agonist, used as
bronchodilators.A.E tremor, interaction with MAOIs.Salmeterol & formoterol:Long acting β2 agonist.Used with steroid mainly for nocturnal
asthma.
INDIRECT ACTING ADRENERGIC AGONISTSEnhances the release of epi. Presynaptically or inhibit the
uptake.AMPHETAMINE:Acts on α1 so BP.On β stimulates the heart. NoteADHS, appetite control, narcolepsy.TYRAMINE:Normal byproduct of tyrosine.Oxidized by MAOI in the gut.COCAINE:Inhibits the reuptake.α1 β effects.
MIXED ACTION ADRENERGIC AGONISTEPHEDRINE & PSEUDOEPHEDRINE:Long duration of action (poor COMT & MAO
substrates).Ephedrine
increases BP by systoilc & diastolic BP & cardiac stimulation.
CNS stimualtion. atheletic performance.Pseudoehedrine:nasal,sinus decongestion.
ADRENER α GIC ANTAGONISTα ADRENERGIC BLOCKING AGENTMainly affecting the BP.Reflex tachycardia.Phenoxybenzamine:Acts on α1 & α2 receptors. peripheral resistance, reflex tachycardia, COP
& restore the decrease in BP.Obsolete in hypertension management.It’s an epinephrine reversal.Used in pheochromocytoma, Raynaud disease.
A.E: nasal stiffness, hypotension.Contraindicated in patients with coronary
perfusion.PHENTOLAMINE:Action as phenoxybenzamine.Used for
short treatment of pheochromocytoma.Norepinephrine administration.Hypertensive crisis with clonidine & tyramine-
MAOI.
Selective α1 inhibitorsprazosin, doxazosin, tamsulosin.Used for: HTN, CCF, BPH.A.E: nasal congestion, headache, orthostatic
hypotension.
Β-adrenergic blocking agentAll are competitive antagonist.Act on both β1 & β2 or are selective β1.Non-selective antagonists:Propranolol:CVS: COP, work, O2 consumption.Blocks β2 peripheral vasodilatation (no
postural hypotension).Bronchoconstriction.Hypoglycemia.
P.K:First-pass effect, Cross BBB.Uses:
1. HTN.2. Hyperthyroidism.3. Angina pectoris.4. M.I.
A.E: bronchoconstriction, arrythmias, drug
interactions. Timolol in chronic open-angle glucoma.
Selective antagonist β1Atenolol, metoprolol, bisoprolol.HTN, diabetes, asthma.Antagonist with partial agonist activity:E.g pindolol & acebutolol.Hypertensive with moderate bradycardia,
DM.Antagonist of both α & β arenoreceptors:Labetalol, carvedilol.Produce peripheral vasodilatation.HTN, PIH, HF.
Drugs affecting neurotransmitter release or uptakeresrpine: move dopamine, serotonin & NE
into the vesicles.Guanethidine: displaces NE from the vesicles.Cocaine: inhibits reuptake.
Thank you