Download - Chapter 19 Adrenoceptor agonists §1. , receptor agonists §2. receptor agonists §3. receptor agonists
-
Chapter 19Adrenoceptor agonists1. , receptor agonists2. receptor agonists3. receptor agonists
-
dopaminenorepinephrineepinephrine
Catechol
-
Structure-activity relationship of catecholamines and related compounds
Substitution on the aromatic nucleus COMT, central activity Substitution on the -carbon atom MAO, uptake-1, NE release Substitution on the amino group sensitivity to the subunits of receptors
-
Metabolism of catecholamines
-
Overview of catecholamines
-
Effect patterns of sympathomimetics
-
Subtypes of adrenoceptors
-
Effects of catecholaminestherapeutic doses
-
Effects of catacholamines and non-catecholamines
-
BP antagonistepinephrineEpinephrine reversaladrenaline reversalepinephrine
-
1. , receptor agonistsEpinephrine , Adrenaline
-
1. , receptor agonists1.1 Pharmacological effects
(1) Cardiac effects 1: HR , output , oxygen consumption , inducing arrhythmia
(2) Vascular effects 1vasoconstriction, especially at larger doses 2vasodilatation of skeletal muscles and coronary vessels
-
(3) Blood pressure SP , DP (at therapeutic doses) (4) Bronchodilatation 2dilatation of bronchial smooth muscles 1reducing congestion and edema of bronchial mucosa
(5) Metabolic effects blood glucose ; free fatty acids 1. , receptor agonists
-
1.2 Clinical uses
(1) Cardiac arrest
(2) Anaphylactic shock
(3) Acute bronchial asthma
(4) Local uses adjuvant for local anesthetics; control of bleeding1. , receptor agonists
-
Clinical uses of epinephrineSystmatic uses:Cardiac arrestAnaphylactic shockAcute bronchial asthmaTopical uses:Adjuvant of local anesthesiaBleeding
-
1.3 Adverse effects
(1) Cardiac arrhythmia: BP , arrhythmia
(2) Excesive rise of BP: cerebral or subarachnoid hemorrhage
(3) Central excitationanxiety
(4) Contraindications: heart diseases, hypertension, coronary arterial disease, arteriosclerosis, hyperthyroidism1. , receptor agonists
-
Ephedrine EphedrineEpinephrine
1. , receptor agonists
-
1.1 Pharmacological effects
Promoting release of NE, weak agonist effects on 1212 receptors
Properties chemically stable, orally effective less potent and longer action duration; central stimulating tachyphylaxis.1. , receptor agonists
-
1.2 Clinical uses
(1) Prevention of hypotension: anesthetics
(2) Nasal decongestion: nasal drop
(3) Bronchial asthma: mild, chronic cases
(4) Relieving allergic disorders: urticaria, angioneurotic edema1. , receptor agonists
-
1.3 Adverse effects
(1) Central stimulation
(2) CVS effects
(3) Dependence1. , receptor agonists
-
Dopamine 1. , receptor agonists
-
1.1 Pharmacological effects
(1) Cardiac effects1 receptor, weak
(2) Vascular effects and blood pressure DA receptordilatation of renal and mesenteric arteries , blood flow (small doses); 1 receptorvasoconstriction of skin, mesenteric vessels (larger doses)
(3) Renal effectsrenal vasodilatation; natriuretic effects1. , receptor agonists
-
VasodilatationVasoconstrictionEffects of dopamine on CVS
-
1.2 Clinical uses (1) Shockcardiac and septic shock: low output, urinary volume , fully adequate replacement of intravascular fluid(2) Acute renal failure combined with furosemide
1.3 Adverse effects tachycardia, arrhythmia, renal vasoconstriction1. , receptor agonists
-
2. receptor agonists 2-1 1, 2 receptor agonistsNorepinephrine , noradrenaline
-
2. receptor agonists2.1 Pharmacological effects
(1) Vascular effects 1vasoconstriction (skin, renal, brain, hepatic, mesenteric, etc.) vasodilatation of coronary arteries 2inhibiting NE release
-
(2) Cardiac effects weak direct stimulation (1); inhibition via reflex
(3) Blood pressure SP , DP (especially at larger doses), larger doses: pulse pressure , blood flow 2. receptor agonists
-
Actions of norepinephrine on post-synaptic (1) and pre-synaptic (2 ) receptors
-
2.2 Clinical uses
(1) Shock BP , blood flow , tissue damage used in early phase of some types of shock or BP rise too slow after treatment: small doses and shorter duration
2. receptor agonists
-
(2) Hypotension due to drug poisoning especially for chlorpromazine
(3) Hemorrhage in upper alimentary tract orally given after dilution2. receptor agonists
-
2.3 Adverse effects
(1) Ischemia and necrosis at the site of iv administration relieved by filtration with procaine or phentolamine(2) Acute renal failure avoiding larger doses and longer duration; monitoring urinary volume(3) Contraindication hypertension, arteriosclerosis, heart diseases, severe urinary volume , microcirculation disorders2. receptor agonists
-
Acting on receptors directly, promoting NE release indirectly
Weaker effects and longer duration than NE, weak for renal vessels;
Used in early phase of shock, hypotensionMetaraminol , Aramine2. receptor agonists
-
2-2 1 receptor agonists
used in hypotension, paroxysmal supraventricular tachycardia (by reflex)Mydriasis (phenylephrine): pupillary dilator muscles, no or less effect on intraocular pressure, short-acting (for several hours) Phenylephrine Methoxamien 2. receptor agonists
-
3. receptor agonists3-1 1, 2 receptor agonistsIsoproterenol , Isoprenaline
-
3. receptor agonists3.1 Pharmacological effects
(1) Cardiac effects 1 receptor stimulation
(2) Vascular effects and blood pressure 2 receptor: dilatation of skeletal muscles and coronary vessels SP DP or pulse pressure
-
(3) Bronchodilatation 2 receptorno effect on edema of mucosa
(4) Metabolism Promoting effects as epinephrine3. receptor agonists
-
Effects of isoproterenol
-
3.2 Clinical uses
(1) Cardiac arrest
(2) A-V block
(3) Septic shocklow-output
(4) Bronchial asthma usually 2 receptor agonists
3. receptor agonists
-
3.3 Adverse effects
(1) Heart stimulation, arrtythmia
(2) Contraindications: coronary heart disease, myocarditis, hyperthyroidism3. receptor agonists
-
3-2 1 receptor agonists
Heart failure
Cardiac stimulationDobutamine 3. receptor agonists
-
3-3 2 receptor agonists
Bronchial asthma
Salbutemol 3. receptor agonists