Chapter 21: Adrenergic Antagonists Flashcards
What are the two major groups of adrenergic antagonists
- alpha-adrenergic blocking agents
- beta-adrenergic blocking agents
main therapeutic applications of the alpha blockade
- essential hypertension
- reversal of toxicity of alpha1 agonists
- benign prostatic hyperplasia (BPH)
- phenochromocytoma
- raynauds disease
what drug should be used to reverse the toxicity of alpha1 agonists
phentolamine
Benign prostatic hyperplasia (BPH) symptoms
dysuria, increased frequency of daytime urination, nocturia, urinary hesitancy, urinary urgency, a sensation of incomplete voiding, a reduction in the size and force of the urinary system
pheochromocytoma
- catecholamine secreting tumor (usually located in the adrenal medulla)
- principle cause of hypertension
pheochromocytoma treatment
surgery is the best option
raynauds disease
- peripheral vascular disorder
- vasospasms in the toes and fingers
- suppress symptoms by preventing alpha mediated vasoconstriction
adverse effects of alpha1 blockade
- orthostatic hypotension
- reflex tachycardia
- nasal congestion
- inhibition of ejaculation
- sodium retention (increased blood volume)
what is the most significant adverse effect associated with the alpha2 blockade
potentiation of reflex tachycardia
Prazosin [Minipress]
- competitive antagonist
- selective blockade of alpha1 adrenergic receptors
prazosin [Minipress] is administered
orally
prazosin [Minipress] antihypertensive effect peak in ______ and persist for ______
1-3 hours
10 hours
prazosin [Minipress] is excreted in
the bile
10% in the urine
prazosin [Minipress] half life
2-3 hours
prazosin [Minipress] adverse effects
- orthostatic hypotension
- reflex tachycardia
- inhibition of ejaculation
- nasal congestion
- ” first dose” effect
