CV Adenosine

Question 1

What are the common diagnostic and therapeutic uses for Adenosine?

Answer 1

Supra ventricular tachycardia (SVT)

Question 2

What is the mechanism of action for adenosine?

Answer 2

1. Agonist of adenosine receptors on cell surface
2. Activation of G protein receptors reduce depolarization
3. Slows sinus rate, conduction velocity
4. Increases AV refractoriness
5. Breaks re-entry circuit
6. Induces cardio version
7. Half life of Adenosine 10 secs

Question 3

How does giving it allows closer inspection of the atrial rhythm on ECG?

Answer 3

By blocking conduction to the ventricles

Question 4

What are the main adverse effects of Adenosine?

Answer 4

1. Bradycardia
2. Asystole
3. Breathlessness: sinking feeling/impending doom

Question 5

What are the main warnings associated with Adenosine?

Answer 5

1. Hypo tension
2. Coronary ischemia
3. Decompensated heart failure
4. Avoid in asthma /COPD

Question 6

What are important drug reactions with Adenosine?

Answer 6

1. Dipyridamole blocks uptake of adenosine, potentiating its effects. Dose should be halved
2. Theophylline, aminophylline and caffeine are competitive antagonists therefore compete/reduce effects

Question 7

How is Adenosine prescribed?

Answer 7

1. IV, written in once only section of drug chart

2. 6mg/12mg, if central line lower dose