Antihypertensives/Beta Blockers Flashcards
labetalol nonselective β-1 effects
decreases HR and contractiliity
labetalol nonselective β-2 effects
vasodilation
where is labetalol selective
α-1 adrenergic agoist
what does labetalol cause at α-1 receptors
arterial vasodilation
labetalol blockade ratio
1 α to 7 β
labetalol uses
acute and chronic HTN in pregnant pts, treat increases in BP and HR from stimulation (intubation)
how does labetalol cause ↓ BP
decreased CO and PVR, can depress cardiac contractility, minimally affects CBP or ICP
when is labetalol contraindicated
bronchospastic disease → impaired cardiac conduction or underlying resting bradycardia
labetalol dose
5-20 mg boluses IV
labetalol onset
1-2 min
labetalol duration
up to 6 hrs
esmolol mechanism of action
Rapid-onset and short-acting selective Beta-1 antagonist
esmolol uses
treat perioperative tachycardia, pre-treatment during intubation/extubation
esmolol ♡ effects
Decrease in HR, myocardial contractility, CO , and some decrease in BP, with no rebound effects
when is esmolol contraindicated
bradycardia
heart block
cardiogenic shock
heart failure
esmolol dose
10mg boluses IV
infusions of 50 mcq/kg/min after a .5mg/kg bolus
esmolol onset and duration
rapid onset; 10-15 min duration
how is esmolol metabolized
by plasma esterases
propranolol class
non selective β-1 and β-2 antagonist
propranolol uses
HTN, angina, acute MI, pheochromocytoma, treat anxiety and panic attacks
how does propranolol work
Decreases BP due to decrease in myocardial contractility, HR, CO therefore decrease in myocardial oxygen demand
propranolol cautions in
bronchospastic disease, AV block, and bradycardia
propranolol dose
1-3 mg IV (no more than 1 mg/min), titrated to effect
propranolol onset
2-3 min
propranolol duration
4-6 hours
metoprolol class
selective β-1 adrenergic receptor antagonist
metoprolol mechanism of action
prevents inotropic and chronotropic responses to β- stimulation
metoprolol uses
rapid HR and contractility control, CO and therefore decrease BP, treatment for MI
metoprolol dose
1-5 mg IV up to 15 mg
metoprolol half life
3-4 hours
vasopressin is also known as
antidiuretic hormone
where is vasopressin released in the body
the posterior pituitary
vasopressin receptors and effects
V1- CV effects
V2- renal
V3- pituitary receptors
vasopressin uses
cardiac arrest (removed from ACLS algorithm), sepsis, shock and hypotension secondary to ACE inhibitors refractory to catecholamines or sympathomimetics
vasopressin dose
mix I0/20 units/ml in a 10/20 ml syringe to get 1 unit/mL concentration
vasopressin dose
1-2 unit bolus
vasopressin is a ____________
potent vasoconstrictor (arterial and mesenteric)
hydralazine mechanism of action
direct systemic arterial vasodilator
how does hydralazine work
causes relaxation of arterial smooth muscle; blocks calcium release from sarcoplasmic reticulum; decreases BP with increase in HR, SV, and cardiac output
hydralazine uses
HTN, heart failure, eclampsia
hydralazine can cause
increased ICP
when is hydralazine contraindicated
in coronary artery disease
hydralazine dose
2.5-5 mg IV titrated q 20-30 min
hydralazine onset
15-30 min
hydralazine duration
4-6 hrs
which drug is contraindicated in bronchospastic disease?
labetalol
which drug is used to treat pheochromocytoma?
propanolol
which drug should be used carefully in bronchospastic disease?
propanolol
which drug can be used for hypotension secondary to ACE inhibitors refractory to catecholamines or sympathomimetics?
vasopressin
which drug decreases blood pressure with an increase in HR
hydralazine
which drug is contraindicated in CAD
hydralazine
