Adenosine
Class
Endogenous nucleotide; antiarrhythmic
Description
Adenosine is primarily formed from the breakdown product of adenosine
triphosphate (ATP). Both compounds are found in every cell of the human body and
have a wide range of metabolic roles. Adenosine slows tachycardias associated
with the AV node via modulation of the autonomic nervous system without causing
negative inotropic effects. It acts directly on sinus pacemaker cells and vagal
nerve terminals to decrease chronotropic and dromotropic activity. Adenosine is
the drug of choice for paroxysmal supraventricular tachycardia (PSVT) and can be
used diagnostically for stable, wide complex tachycardias of unknown type after
two doses of lidocaine.
Onset & Duration
Onset: almost immediate
Duration: 10 sec
Indications
Conversion of PSVT to sinus rhythm
Contraindications
1. Second- or third-degree AV block
2. Sick sinus syndrome
3. Hypersensitivity to adenosine
Adverse Reactions
1. Facial flushing
2. Lightheadedness
3. Paresthesia
4. Headache
5. Diaphoresis
6. Palpitations
7. Chest pain
8. Hypotension
9. Nausea
10. Metallic taste
11. Shortness of breath
Drug Interactions
1. Methylxanthines (for example, caffeine and theophylline) antagonize the
action of
adenosine.
2. Dipyridamole potentiates the effect of adenosine; reduction of adenosine dose
may be
required.
3. Carbamazepine may potentiate the AV-nodal blocking effect of adenosine.
Special Considerations
1. Pregnancy safety: Category C
2. May produce bronchoconstriction in patients with asthma or bronchopulmonary
disease.
3. At the time of conversion asystole or new rhythms may result. These generally
last a
few seconds without intervention; patient may have transient symptoms
4. Adenosine is not effective in atrial flutter or fibrillation
5. Must administer rapidly (IV slam), due to short duration/half-life. Always
follow with NS
flush
Note: Feel free to discuss this medication and your experiences in administering it in an emergency or hospital based setting on our message board
