Beta Antagonists and Vasodilators Flashcards
Esmolol Class
selective B1 antagonist
Esmolol Use
used to prevent or minimize tachycardia and hypertension in response to perioperative stimuli (such as intubation, surgical stimulation, and emergence)
May decrease post op opioid requirements
Esmolol MOA
Competitive antagonist of B1 receptors (inhibits B2 receptors at higher doses)
Esmolol Dose
0.5mg/kg or 10mg
Infusion = 50 mcg/kg/min
(Uptitrate q5min to max dose 200 mcg/kg/min)
Esmolol Pharmacokinetics
Onset = 1 - 2 min DOA = 5 - 10 min Metabolism = rapid hydrolysis by plasma esterase metabolism in RBCs Elimination = renal
Esmolol Contraindications
Bradycardia, 1st degree heart block, cardiac failure
Esmolol Considerations
Caution in patients with hypotension and bronchoconstriction
Labetolol Class
Non-selective alpha and beta antagonist
Labetolol Use
treat tachycardia and hypertension
Labetolol MOA
competitive antagonist of B1, B2, and A1 receptors
Beta blockade to alpha blockade is 7:1
Labetolol Dose
Intermittent bolus 5 - 20 mg
Labetolol Pharmacokinetics
Onset = 5 min DOA = 3 - 6 hours Metabolism = hepatic Elimination = hepatic and renal
Labetolol Contraindications
Caution in patients with asthma, COPD, bradycardia, hypotension, and CHF
Labetolol Considerations
May cause left ventricular failure, orthostatic hypotension, and bronchospasm
Nitroglycerin Class
Peripheral vasodilator, venous dilation predominating over arterial dilation
Nitroglycerin Use
Relieves myocardial ischemia, coronary vasospasm
Nitroglycerin MOA
Comes from it’s metabolism
As NTP is metabolized, it released nitric oxide + cyanide
NO activates guanylyl cyclase, which synthesize cGMP, decreases intracellular calcium, causing SM dilation