Adenosine (Adenocard)

Question 1

Adenosine Classification

Answer 1

Antidysrhythmic (Class V)/Nucleoside

Question 2

Adenosine Mechanism

Answer 2

Adenosine (A1)R agonist -> slows AV conduction by activations of G-protein 2nd messengers, decreasing cAMP and inhibiting Ca2+ entry into the cardiac pacemaker cells

Question 3

Adenosine Pharmacokinetics

Answer 3

Onset: Immediate
Peak Effects: Immediate
Durations: 30-45 sec
Half Life: 6 sec

Question 4

Adenosine Indications

Answer 4

• SVT (PSVT)/ Narrow Complex Tachycardia
• Diagnostic maneuver: stable narrow complex SVT
• wide regular monomorphic tachycardia

Question 5

Adenosine Contraindications

Answer 5

• 2/3 degree Heart Block, Sick Sinus Syndrome, Torsades (Polymorphic VT)
• Poison/Chemical induced SVT (ie. Cocaine)

Question 6

Adenosine Side Effects/Adverse Reactions

Answer 6

Facial flushing, HA, CP, dizziness

Question 7

Adenosine Dose

Answer 7

Adult:
1st dose = 6mg rapid IVP (proximal vein) followed by 20cc NS flush
2nd dose = 12mg rapid IVP followed by 20cc NS flush
Pedi:
1st dose = 0.1 mg/kg IV IO rapid push (proximal vein), max 6mg
2nd dose = 0.2 mg/kg IV IO rapid push, max 12mg

Question 8

Adenosine Precautions

Answer 8

• Begin printing rhythm strip before administering adenosine

- Caution with asthma and COPD - may induce wheezing

Question 9

Adenosine Drug Interactions

Answer 9

• Methylxanthines (caffeine) are nonspecific competitive antagonists for adenosine receptors; Double the dose for pts taking large amounts
• Carbamazepine (tegretol, phenobarbital) and dipyridamole (persantine, aggrenox) potentiate effects of adenosine; halve the dose