sympathetic pharmacology

adrenoceptors

three main types

Alpha

Beta

Dopamine

a-1 prostate

a-2 postsynaptic CNS

B-1 heart

B-2 lungs

D-1

D-2

D-3

effects of sympathomimetics

mimics fight or flight response

increase heart rate, bronchodilation, and wakefulness and alertness

clinical effects

eye

a-2 agonist (brimonidine) increase outflow of aqueous humor

cardiovascular

a-1 agonist midodrine causes peripheral vasoconstriction

B-1 agonist dobutamine and isoproterenol have positive chronotropic and inotropic effects

respiratory system

beta agonists cause bronchodilation

CNS

a-2 agonist (clonidine) decrease sympathetic tone and blood pressure

indirect acting agents that increase levels of norepinephrine include tricyclic antidepressants and amphetamines

uterus

B-2 agonist terbutaline relaxes pregnant uterus to stop premature labor

anaphalaxis

severe allergic reaction

bronchospasm, mucous membrane congestion, hypotension

epinephrine administered via injection is treatment of choice

activated alpha, B-1, and B-2 receptors

adrenergic blockers

adverse effects

alpha blockers

dizziness and orthostatis hyotension

beta blockers

bradycardia, coolness in hands and feet, mild sedation, vivid dreams, depression, worsening asthma, erectile dysfunctions