Chapter 13: Adrenergic Drugs Flashcards
Epinephrine
A nonselective adrenergic agonist that stimulates all SNS receptors and is used to tx anaphylactic shock, asthma, v-fib… Agonistic effects include: increased heart rate and contractility, increased BP, and bronchodilation. Adverse effects include tremor, dizziness, anxiety, pallor, palpitations, sweating, and N&V. Epi can also lead to arrythmias, angina, hemorrhage, and HTN crisis.
Phenylephrine (Allerest)
An alpha-1 agonist and vasopressor that is used to tx hypotension/vascular failure in shock and nasal congestion. The drug causes vasoconstriction and increased BP, but also decreased CO and renal perfusion. Adverse effects include headache, restlessness, and reflex brady-c from increased BP.
Clonidine (Catapres)
Alpha-2 agonist/antihypertensive that inhibits NE release via negative feedback loop. The drug causes a decrease in PR, BP and HR. Its effects are limited.
Dopamine (Intropin)
A catecholamine/beta-1 agonist used to correct the hemodynamic imbalances present in shock. Beta-1 stimulation leads to increased CO secondary to increased HR and contractility, systolic BP increases, and renin release. (also stim dopamine receptors–vasodilation). Adverse effects include ectopic beats, N&V, tachy-c, angina, palpitations, dyspnea, headache, hypotension, and vasoconstriction.
Fenoldopam (Corlopam)
Dopaminergic agonist that causes rapid vasodilation (coronary, renal, peripheral arteries) and is used for the short-term tx of severe HTN. Adverse effects include symptomatic hypotension (syncope), tachy-c, abd. or back pain, GI effects, sweating, CNS effects (insomnia, dizziness, nervousness).
Prazosin (Minipress)
An alpha antagonist that blocks alpha receptors causing vasodilation and decreased BP. Prazosin is used to tx CHF, HTN, BPH and raynaud syndrome. Adverse effects include light-h, ortho. hypo, headache, D/D, lethargy, nausea, tachy-c, palpitations.
Metaprolol (Lopressor)
nonselective beta-antagonist that causes a decreased HR w/ slowing of conduction/automaticity, decreased CO and BP. Metaprolol is used to tx HTN, angina, CHF, post MI, and CV irregularities. Side effects include hypotension, brady-c, heart block, worsening heart failure, depression, dyspnea, dizziness, and fatigue.
Alpha-1 receptor stimulation
causes vasoconstriction of coronary vessels, and decreased GI motility.
Alpha-2 receptor stimulation
inhibits the release of NE, thus decreasing adrenergic effects (decreased BP/HR). These receptors are located on presynaptic neurons and act as a negative feedback mechanism.
Beta-1 receptor stimulation
causes increased HR and increased contractility to increase CO.
Beta-2 receptor stimulation
causes bronchodilation, increased energy from glucose/insulin release and breakdown of fats, vasodilation, detrusor relaxation (urine storage), decreased GI motility, increased renin release, and thickened saliva.
Adrenergic stimulation acronym: “FLIGHT”
Facilitates breathing, Limits salivation and sex organ function, Increases PR and BP, GI motility decreases, Have more energy, and Tachy-c (increased HR).
