Adenosine

Question 1

Generic name?

Answer 1

Adenosine

Question 2

Class?

Answer 2

Antiarrhythmic

Endogenous nucleoside

Question 3

Mechanism of Action?

Answer 3

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 4

Indications?

Answer 4

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

Question 5

Contraindications?

Answer 5

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

Question 6

Side effects?

Answer 6

CV: Transient dysrhythmias (systole, bradycardia, PVC’s) occur in 55% of patients (none reported as irreversible). Palpitations, chest pressure, chest pain, hyotension, 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 7

Adult Dose?

Answer 7

Initial: 6mg rapid IV bolus over 1-3 seconds
Special adminitration procedure: Follow immediately with 20ml 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 (ofeach dose, respectively) may repeat 12mg utilizing the same procedure for the repeat dose.

Question 8

Pediatric Dose?

Answer 8

Initial: 0.1mg/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.
(DRUG CHOICE FOR TREATING SVT IN SYMPTOMATIC INFANTS & CHLDREN)

Question 9

Onset?

Answer 9

Onset of Action: Seconds
Peak Effects: Seconds
Duration of Action: 10-12 seconds (1/2 life 5 seconds)
Rapid IV Push

Question 10

Special Notes?

Answer 10

Dysrhythmias may recur (short half life)
Dysrhymias appear in 55% of patients at conversion, lasting for a few seconds, do not usually requre intervention.
Check for crystallization in cold climates.
Adenosine is not blocked by Atropine.
Dipyridamoe (Persantine) & carbamazepine (Tegretol, Atretol) block uptake & potentiate effects.

Question 11

Trade Name?

Answer 11

Adenocard