Anti- Arrthmyic Flashcards
Amiodarone
Amiodarone
class: class III anti-arrthymic
MOA:
Has class I, II, III, and IV properties, blocsk the entry of Ca++, K+, Na++ into myocardial cells and is also an alpha and beta adrenergic antagonist.
Uses:
Prophylaxis of a.fib or tx of acute A.fib, used to tx atrial and ventricular tacchyarrthymias as 2nd line for VF/VT when electrical defibrillation fails.
Pk:
pB: high
vD: Large
e1/2T: 10-100 days
metabolized in liver, biliary/intestinal excretion.
Inhibits CYP450 enzymes.
Dose:
150-300 mg bolus over 2-5 minutes followed by 1 mg/kg for 6 hours and 0.5 mg/kg for 18 hours.
SE:
Pulmonary fibrosis, toxicity
pumlonary edema, ARDs
thyroid dysfunction
HB/AV block
Hypotension/ bradycardia
Hepatoxicity
PROARRTHYMIC effect - prolong qt - torsades
Skin discoloration - grey/blue
photosensitive rashes
C/I:
AV block/HB
Concurrent use with other drugs that prolong QT
Iodine allergy
DECREASE CLEARANCE OF DIG AND WARFARIN
avoid use with lido/bb/ccb
Lidocaine
Lidocaine
class Ib anti-arrthymic and amino amide local anesthetic
MOA: depresses the phase of the action potential and shortens AP duration and refractory period by binding to VGNa+ channels and blocking the influx of Na+ into myocardial cells.
As a local anesthetic it binds to VGNa+ and prevents depolarization and neuronal transmission of impulses.
Lidocaine binds best to VGNa+ channels in inactive or open states and so it is called a use-dependent block.
As an anti-arrthymic it used to tx ventricular tachyarrthmias, re-entry arrthymias, Vfibs, PVCs. also used to attenutate the SNS response to DVL.
Pk:
Onset: immediate
DOA: 2 hours
e1/2t - anti -a : 8 hours
e1/2 - LA - 96 minutes
metabolized by cyp450 enzymes, has 2 active metabolites (monoethy–xylidide)
Dose:
Max LA: 4mg/kg with epi is 7 mg/kg
Max for anti-a 3 mg/kg
usual dose for Anti-A/intubation: 1-1.5 mg/kg
SE:
Hypotension, bradycardia, myocardial depression
seizures, CNS, depression dizziness
Sinus arrest, HB, vent. depression
Can augment NMB
hepatoxicity
transient neurologica symptoms with neuraxial anesthesia and r/f cauda equina syndrome when using higher concentration in neuraxial anesthesia
C/I:
Hypersensitive to amide LAs
Methemoglobinemia
WPW
HB
hepatic dx
will be affected and have decreased metabolism with propanolol, cimetidine,
