ANS Pharm Flashcards
NE
Sympathomimetics (agonists)
a1=a2 B1»B2
increases contractility (force) and decreases heart rate (reflex)
VC of blood vessels—>inc BP (pressor)
Epi
Sympathomimetics (agonists)
a1=a2 B1=B2
Isoproterenol
Sympathomimetics (agonists)
B1=B2»»»»a (pure beta agonist)
Phenylephrine
a selective agonist
pressor agent—>increase TPR,—>inc BP—>reflex decrease in HR
a1>a2»»»»>.B
Albuterol
B2 selective agonist
used to treat asthma, bronchodilation
B2»>B1»»»>a
Dobutamine
B1 selective agonist
used in MI, CHF, cardiogenic shock to increase CO
B1>B2»a
DA
DA agonist
D1=D2»B»>a
Propranolol
Nonselective B antagonist
dec HR and CO—>dec work of heart and O2 demand
**blocks SNS BD—>contraindicated in asthma and COPD
may mask signs of hypoglycemia(contraindicated in diabetics)
B1=B2»>a
Atenolol and Metoprolol
B1 selective B antagonist
B1»>B2
lessens risk for bronchospasm (comp to propanolol)
has been shown to improve outcomes in CHF patients
Phentolamine
Non selective a antagonist
a1=a2
Prazosin
a1 selective a antagonist
a1»»»»>a2
Higher risk for syncope events
used to lower BP (HTN)
Carvedilol
Mixed antagonist
can be used to treat HTN
B1-B2>_a1>_a2
Acetylcholine
muscarinic and nicotinic agonist
Bethanechol
Muscarininc cholinergic agonist
M1-5»»»NmNN
Atropine
Muscarinic receptor antagonists
reverses reflex bradycardia
can also be used in COPD and asthma to improve BD
M1-4»»>NmNn
a1 receptors
agonism causes contraction of vascular smooth muscle
vasoconstriction
—>main regulator of blood pressure
pupil, spleen, uterus, errector pili etc
stimulates glycogenolysis
EPI>NE»ISO
a2 receptors
agonism cause vasoconstriction (just at different places than a1)
minor physiological role
may stimulate autoreceptors that decrease NE release from neurons
EPI>NE»ISO
B1 receptors
found in the heart stimulates increased HR
increases contractility
ISO>EPI»NE
B2 receptors
agonism causes smooth muscle relaxation
**think bronchioles, and certain vascular beds
stimulate skeletal muscle K uptake
also has metabolic (glycogenolysis) and humoral (insulin) affects
ISO>EPI»>NE
DA receptors
renal afferent blood vessels
D1—>Dilation
increase blood flow to the kidney
used in cardiogenic shock (heart is not delivering enough O2 to tissues—> dec flow to kidneys) give IV DA—>improve renal blood flow and at high enough doses you can activate B1 (good) or a1 (bad)
at high enough doses it can bind B1 and a1
EPI and the heart
inc HR, inotropy—>inc work by heart—>inc O2 demand***
Epi in the blood vessels
can stimulate a1 and B2
B2>a1
***different distribution and density of receptors in different receptor beds
skeletal muscle (both B2 and a1, dose dependent vasodilation-B2 first, the a1)
Ipratropium bromide
Tiotropium
inhalation only
Muscarinic receptor antagonist—>decreases BC
use with albuterol to open up airway in pt with COPD
