Test 1: Wk3: 3 Adrenergic Agonists and Antagonists - Salisbury Flashcards
indirect sympathomimetic agents MOA
indirect acting drugs ⬆️ The availability of NE or EPI
4 indirect acting releasing agents
- Amphetamine
2 Methylphenidate
3 Tyramine
4 Ephedrine
Ephedrine can also stimulate … and …
alpha and Beta Receptors
Indirect acting Releasing Agents uses
ADHD
Hypotension
2 Indirect Acting uptake inhibitors
1 cocaine
2 TCA impiramine
Indirect Acting uptake inhibitors uses
Depression
Indirect Acting MAO inhibitors
TranyIcypromine
Phenezine
selegiline
Indirect Acting uptake inhibitors COMT inhibitors
Intacapone
Talcapone
Indirect Acting uptake inhibitors MAO inhibitors uses
Depression
Avoid … w/ MOA inhibitors
Tyramine causes hypertensive crisis
Indirect Acting uptake inhibitors COMT inhibitors uses
Parkinson’s
⬆️ Levodopa
Direct Acting sympathomimetic Drugs
catecholamines
Noncatecholamines
catecholamines (5)
1 Dopamine 2 Isoproterenol 3 NE 4 EPI 5 Dobutamine DINED
Can catecholamines and noncatecholamines be given orally
No they’re too rapidly metabolized
Noncatecholamines (3)
1.phenylephrine
2 ephedrine
3 amphetamine
a 1
vasoconstriction
B2
vasodilation
Norepinephrine Receptors
a1 a2 B1»_space;> B2
Epinepherine Receptors
a1 a2 B1 B2
Isoproteronol Receptors
B1 B2»_space;> a1
Norepinephrine effect on pulse rate
Slight decrease a1»_space; B2
Epinephrine effect on pulse rate
Slight increase, dose Dependent B2 > a1
Isoproterenol effect on pulse rate
Increase B2»_space;> a1
NE effect on BP
increase
Epi effect on BP
slight increase
Isoproterenol effect on BP
slight decrease
NE effect on peripheral resistance
increase
Epi effect on peripheral resistance
slight decrease
Isoproterenol effect on peripheral resistance
decrease
Low dose Epi
higher affinity for B2
TPR decrease
Epi high dose
Epi receptor selectivity is lost
a1=B2
TPR increase and MBP
Epi reversal
Phenoxybenzamine
a1 and A2 block
adrenergic agonists MOA
mimic effects of SNS - sympathomimetic
adrenergic agonists exception
a2 receptor agonists are sympatholytic
Epinephrine is an agonist at
a1, a2, B1, B2
Epi causes
bronchodilation - B2
Epi CV effects low dose
vasodilation - B2 more sensitive than a receptors
tachycardia - direct B1
Epi CV effects low dose net
net effect ⬆ TPR, slight ⬆ BP ⬆HR
Epi CV effects high dose
vasoconstriction - a receptor activation dominates)
⬆ TPR ➡ ⬆ BP
direct B1 ➡ ⬆HR
Epi CV effects high dose net
⬆ TPR ⬆BP ⬆HR
Epi metabolic effects
- hyperglycemia
- ⬆ glycogenolysis and gluconeogenesis
- ⬆ blood glucose
- ⬆ free FAs in blood
- ⬇ plasma K+
Epi a2 does what to insulin secretion
⬇⬇
Epi B2 does what to insulin secretion
⬆
Epi a2>B2 net effect on insulin
⬆
Epi what receptor ⬆ glycogenolysis and gluconeogenesis
B2
Epi — receptors in adipocytes — FFAs in blood
B; ⬆
Epi — receptors — K+ plasma concentrations
B2; ⬇
they increase K+ uptake thus lowering it in plasma
Epi therapeutic uses (5)
1 Anaphylaxis 2 Bronchospasm 3 Cardiac Arrest 4 prolong action of local anesthetic 5 glaucoma
Epi kinetics
catecholamine
not effective orally must be IV
Epi adverse effects (4)
1 marked hyperglycemia
2 cardiac stimulation
3 vasoconstriction
4 CNS stimulation
Epi vasoconstriction adverse effects
hypertension, slough at injection site
Epi CNS Stimulation Adverse Effects
⬆ respiration, apprehension, tremor
Epi contraindications
tachyarrhythmias, hyperthyroidism
⬆ toxicity with MAO inhibitors
NE is an agonists at
a1, a2, B1
NE CV effects
vasoconstriction ➡ ⬆TPR ➡⬆ mean BP
+- HR ➡ direct B effect + reflexes ➡ +- HR
NE CV net effects
⬆ TPR ⬆ BP +- HR
NE therapeutic effects
septic and cardiogenic shock
MOA vasoconstriction + inotropic
NE Kinetics
catecholamine IV only
NE adverse effects
cardiac - arrhythmias, angina
vasoconstriction - hypertension
NE Contraindications
tachyarrhythmias, hyperthyroidism, hypertension
⬆ toxicity with MAO Inhibitors
⬆ toxicity with cocaine and reuptake inhibitors
Dopamine is a direct — at —- — receptors
agonist, dopaminergic, D1
what does dopamine do
dilates renal, splanchnic, cerebral, and coronary vessels
Causes release of NE
Dopamine CV Low dose
D1 receptor mediated selective vasodilation of renal and splanchnic vessels
Dopamine CV moderate dose
D1 receptor mediated vasodilation ➡ ⬇ TPR
Direct and reflex B1 receptor mediated effects ➡⬆HR, ⬆ CO
+- BP