Adenosin (Jan 2010)

Question 1

TYPE:

Answer 1

Endogenous purine nucleoside, found in all body cells [S4]

Question 2

PRESENTATION:

Answer 2

6 mg in 2ml ampoules

Question 3

ACTION:

Answer 3

Causes transient inhibition of conduction in the heart,
especially in the A-V node.
Onset: 5 – 10 seconds - Duration: approx 10 seconds

Question 4

USE:

Answer 4

Treatment of supraventricular tachycardia
Not for the treatment of Atrial Flutter or Fibrillation; however, if mistakenly administered to patients in these arrhythmias, the decrease in A-V conduction may unmask atrial activity.

Question 5

ADVERSE EFFECTS:

Answer 5

Common, although transient & generally minor.
Arrhythmias at the time of conversion are common (up to 55% pts) - including PVCs, PACs, sinus brady, A-V blocks.
Transient flushing of the skin; mild dyspnoea; chest
tightness, nausea & headache, feelings of apprehension & fear.

Question 6

CONTRA-INDICATIONS:

Answer 6

2° or 3° heart block

Known hypersensitivity

Question 7

PRECAUTIONS:

Answer 7

Asthma - may exacerbate bronchospasm.
Pregnancy - use only if very poorly perfused.
Antagonised by: Theophylline
Potentiated by: Dipyridamole (Persantin)
Carbamezapine
(Carbium, Tegretol, Teril)

Question 8

DOSE:

Answer 8

Symptomatic adults only:
6 mg IV - rapid bolus (1 – 2 seconds)
give into a fast-flowing pump set
If 1st dose unsuccessful, give 2nd dose
12 mg IV (2 minutes between doses)
Paediatric: 0.05 mg/kg
2nd dose: 0.1 mg/kg

Question 9

SPECIAL NOTE:

Answer 9

Use only after unsuccessful Valsalva manoeuvre x 2.
Record a 12 lead ECG prior to the use of Adenosine.
Rapid injection with a pump set increases the likelihood of success.
Elevate limb if possible.
Even if the arrhythmia is successfully converted – the patient should still be transported to
hospital as the incidence of recurrent arrhythmias is quite high (10-15%).
If patient has previously had an unpleasant (fearful) experience with Adenosine
– consider a pre-dose of Midazolam 1 – 1.5mg IV.