Adenosine (Adenocard)

Question 1

Class

Answer 1

Antiarrhythimic (antidysrhythmic)

Question 2

Action

Answer 2

Endogenous nucleoside (found in all the cells of the body and is formed from the breakdown of ATP) depresses AV node and sinus Node activity.
Decrease conduction through the AV node and interrupts AV nodal reentry pathways that cause SVT.
Works both at the A-V node and in aberrant conduction pathways, ie, WPW (Wolff-Parkinson-White) LGL (Lown-Ganong-Levine).
Does not convert atrial fibrillation/flutter but may transiently increase AV block and unmask flutter waves. Cleared from plasma in <30 seconds, half life is 10 seconds. A brief period of asystole (up to 15 seconds) is common.

Question 3

Indications

Answer 3

SVT’s thought to be due to reentrant mechanisms

Question 4

Contraindications

Answer 4

Hypersensitivity

2nd or 3rd degree heart block or sinus node disease SSS (sick sinus syndrome) unless has a functioning pacemaker.

Question 5

Side Effects

Answer 5

Flushing
Chest pain
Dyspnea
Metallic Taste
Arrhythmias: PAC’s, 2nd or 3rd degree heart block, asystole, ventricular ectopy
Bronchoconstriction- rare (esp. in reactive airway disease, ie. asthma, COPD)
Note: Adenosine has a half-life of about 10 seconds so these side effects are usually transient and resolve withing 1-2 minutes

Question 6

Precautions

Answer 6

Patients taking theophyllines, caffine, or theobromine, may need higher doses. Use with caution in denervated, transplanted hearts and may require only a small dose
Reactive airway disease- increase bronchoconstriction