Adenosine

Question 1

Class

Answer 1

Endogenous nucleoside, miscellaneous antidysrythmic

Question 2

Mechanism of action

Answer 2

Slows supraventricular tachycardias by decreasing electrical conduction through the atrioventricular (AV) node without causing negative inotropic effects. Also acts directly on sinus pacemaker cells and vagal nerve terminals to decrease chronotropic activity.

Question 3

Onset and duration

Answer 3

Onset: immediate
Duration: 10 seconds

Question 4

Indications

Answer 4

First drug for most forms of narrow-complex paroxysmal SVT and dysrythmias associated with bypass tracts such as Wolff-Parkinson’s-White syndrome n adults and pediatric patients.

Question 5

Contraindications

Answer 5

Drug-induced tachycardia
Second or third degree AV block
Hypersensitivity to adenosine
Atrial flutter, Atrial fibrillation, Ventricular tachycardia, WPW with atrial flutter/fibrillation

Question 6

Adverse reactions

Answer 6

Facial flushing
Light-headedness 
Paresthesias
Headache 
Diaphoresis
Palpitations 
Chest pain 
Flushing
Hypotension, SOB, sinus bradycardia, ventricular ectopy, nausea, metallic taste

Question 7

Drug interactions

Answer 7

Methylxanthines ( caffeine, theophylline) antagonize the action of adenosine
Dipyridamole potentiates effect (reduction of dose may be required
Carbamazepine may potentiate AV-nodal blocking effect

Question 8

How supplied

Answer 8

Parental for IV injection

3mg/ml in 2ml and 4ml flip top viles

Question 9

Dosage and administration-adult

Answer 9

Initial dose: 6mg rapid IV bolus over 1-3 seconds, followed by 20cc saline flush then elevate extremity. Second dose of 12mg may be given in 1-2 minutes if needed.

Question 10

Injection technique

Answer 10

Place patient in mild reverse Trendelenburg position before drug administration. Record ECG during drug administration. Administer as rapidly as possible either diluted or followed by a flush.

Question 11

Dosage and administration-pediatric

Answer 11

Initial dose 0.1mg/kg IV or IO (max single dose 6mg); second dose 0.2 mg/kg rapid push; followed with 5-10ml flush.

Question 12

Special considerations

Answer 12

Pregnancy safety category C
Brief period of asystolye (up to 15 seconds) following conversion followed by NSR common after administration
Reduce dose to 3mg in heart transplant patients, patients with potentiating drugs.
Deterioration may result if given for irregular, polymorphic wide complex tachycardia/VT