ADENOSINE (ADENOCARD)

Class

Antiarrhythmic

Pharmacology and Actions

1. Adenosine is an endogenous nucleoside with antiarrhythmic activity.
2. Because of its short plasma half-life (less than 10 seconds with IV doses), the clinical effects of adenosine occur rapidly and are very brief.
3. Produces a transient slowing of the sinus rate
4. Has a depressant effect on the AV node.

Indications

1. For termination of episodes of acute supraventricular tachycardia involving the AV-node.

Contraindications

1. Second or third-degree heart block
2. Sick sinus syndrome
3. Known hypersensitivity to drug

Precautions

1. Adverse effects include hypotension, flushing, dyspnea, chest pain, anxiety, and occasionally, hemodynamic disturbances - all of which are of short duration.
2. Transient arrhythmias including asystole and blocks are common at the time of chemical cardioversion.

Administration

1. Direct rapid intravenous bolus over 1-2 seconds of 6mg initially, followed immediately by 20mL saline flush.  A second dose of 12 mg may be given after an interval of 1-2 minutes if the tachycardia persists.
2. Pediatric dose: rapid IV 0.1 mg/kg IV/IO initial dose followed immediately with a saline flush (greater than 5mL). Second dose 0.2 mg/kg rapid IV/IO if SVT persists. Maximum first dose is 6 mg. Maximum second dose is 12mg.

Side Effects and  Notes

1. Whenever possible, establish the IV at the antecubital
2. Adenosine is safe in patients with Wolff Parkinson-White Syndrome.
3. Concomitant use of dipyridamole (Persantine) enhances the effects of adenosine. Smaller doses may be required.
4. Caffeine and theophylline antagonize adenosine's effects. Larger doses may be required.
5. Warn patients to expect a brief sensation of chest discomfort.
6. If patient becomes hemodynamically unstable, see appropriate tachycardia algorithm.
7. Stable, asymptomatic patients, without a history of PSVT, may not need to be treated.
8. Any patient receiving adenosine must be on a monitor and a 12-lead EKG should be performed and documented, if available.