Adenosine

Question 1

Class

Answer 1

antidysrhythmic

endogenous nucleoside

Question 2

Action

Answer 2

Endogenous nucleoside found in all cells of the body, formed from the breakdown of ATP, depresses AV and sinus node activity.
Decrease conduction through the AV node and interrupt AV nodal reentry pathways that cause SVT.
Works at both the AV node and in aberrant conduction pathways, i.e. WPW (wolf parkinson white) or LGL (lown ganong levine).
Does not convert a fib/a flut, but may transiently increase av block and unmask flutter waves. cleared from plasma in less than 30 secs. half life is 10 secs. asystole for up to 15 seconds is common.

Question 3

Indications

Answer 3

SVTs thought to be due to re-entry mechanisms.
ACLS - terminates those due to reentry at SA or AV nodes
ACLS - wide complex tachycardia thought to be or previously defined to be reentry SVT

Question 4

Contraindications

Answer 4

Hypersensativity
A fib/A flut/V tach
2nd or 3rd degree block
sinus node disease SSS sick sinus syndrome unless there is functional pacemaker.

Question 5

Side effects

Answer 5

Flushing
Dyspnea
Cp
Metallic taste
bronchoconstriction-rare (especially in reactive airway disease)
Ha
lightheadedness
nausea
arrhythmias: PACs, asystole, ventricular ectopy, 2nd or 3rd degree blocks
Note: SEs usually resolve within 1-2 minutes

Question 6

Precautions

Answer 6

pts taking theophyllines, caffiene, or theobromine may need higher doses.
use caution with denervated transplanted hearts(may require lower dose)
reactive airway disease
lower the dose for pts taking dipirydamole persantine tegretol carbamazepine
Wide complex tachycardia / v-tach may cause deterioration and hypotension