Adenosine

Question 1

Adenosine Class

Answer 1

Antiarryhthmic, endogenous nucleosides

Question 2

Adenosine MOA

Answer 2

• Slows conduction time through AV node; can interrupt re-entrant pathways through the AV node.
• Slows sinus rate.
• Larger doses decrease BP by decreasing peripheral resistance.

Question 3

Adenosine Indications and Field Use

Answer 3

• Conversion of supraventricular tachycardias with no known atrial fibrillation or atrial flutter.
• Undifferentiated regular monomorphic wide-complex tachycardia

Question 4

Adenosine Contraindications

Answer 4

• Sick sinus syndrome, 2nd or 3rd degree AV blocks; except in patients with a functioning ventricular pacemaker.
• Use cautiously in patients with known asthma (has precipitated acute bronchospasm).
• Patients on theophylline and related methylxanthines.
• Patients on dipyridamole (Persantine) or carbamazepine (Tegretol).
• Cardiac transplant patients are more sensitive to adenosine and require only a small dose (relative).
• Known atrial fibrillation or atrial flutter.
• Pregnancy (no controlled studies)

Question 5

Adenosine Adverse Reactions

Answer 5

CV: Transient dysrhythmias (systole, bardycardia, PVC’s) occur in 55% of patients (none reported as irreversible). Palpitations, chest pressure, chest pain, hypotension, transient hypertension; facial flushing, sweating.
Resp: Dyspnea, hyperventilation, tightness in throat, bronchospasm.
CNS: Lightheadedness, headache, dizziness, paresthesias, apprehension, blurred vision, neck-back pain.
GI: Nausea, metallic taste.

Question 6

Adenosine Incompatibilities/Drug Interactions

Answer 6

• Adenosine is not blocked by Atropine.
• Theophylline and related methylxanthines (caffeine & theobromine-xanthine) in therapeutic concentrations decrease effectiveness.
-Dipyridamole (Persantine) & carbamazepine (Tegretol, Atretol) block uptake and potentiate effects.

Question 7

Adenosine Adult Dosage

Answer 7

• Initial: 6 mg rapid IV bolus over 1-3 seconds
• Special administration procedure: Follow immediately with 20 ml normal saline flush.
IV site recommended is antecubital fossa (close to central circulation); use injection port nearest hub of IV catheter; arm elevated during procedure; constant ECG monitoring.
• Repeat: If no response in 1-2 minutes (of each dose, respectively) may repeat 12 mg utilizing the same procedure for the repeat dose.

Question 8

Adenosine Pediatric Dosage

Answer 8

(Drug of choice for treating SVT in symptomatic infants and children)
• Initial: 0.1 mg/kg as a rapid IV bolus.
• Special administration procedure: Follow immediately with 2-3 ml normal saline flush. Use injection port nearest the hub of IV catheter for procedure; constant ECG monitoring.
• Repeat: If no response, dose may be doubled 1 time (0.2 mg/kg) using same administration procedure.
• Maximum single dose: Should not exceed 12 mg.
• Infants with SVT associated with shock: Adenosine may precede cardioversion if
vascular access is available, but cardioversion should not be delayed while IV access is achieved.

Question 9

Adenosine Routes

Answer 9

Rapid IV push

Question 10

Adenosine Onset

Answer 10

Seconds

Question 11

Adenosine Peak

Answer 11

Seconds

Question 12

Adenosine Duration

Answer 12

10-12 seconds

Question 13

Adenosine AZ Drug Box Minimum

Answer 13

18 mg