The Effects of Adenosine:
Adenosine is effective in terminating narrow complex SVT due to reentry involving AV node or sinus node. It is used for unstable narrow-complex reentry tachycardia. Adenosine should be given while preparing to cardiovert.
Adenosine does not convert atrial fibrillation, atrial flutter, or ventricular tachycardia.
Adenosine Indications for Use:
Adenosine is indicated for:
- Narrow-complex supraventricular tachycardia or SVT
- Unstable narrow-complex reentry tachycardia
- Regular and monomorphic wide-complex tachycardia
- As a diagnostic maneuver for stable narrow-complex SVT
Adenosine Precautions & Contraindications:
Adenosine is contraindicated in poison/drug induced tachycardia or second or third degree heart blocks. It is safe to use during pregnancy.
It is less effective in patients taking theophylline or caffeine. If administered for irregular polymorphic wide-complex tachycardia or ventricular tachycardia, it may cause deterioration, including hypotension.
Side effects include
- Transient periods of flushing
- Chest pain or tightness
- Brief periods of asystole or bradycardia
- Ventricular ectopy
The initial dose should be reduced to 3 mg when:
- Patient is receiving dipyridamole or carbamazepine
- Patient has had a heart transplant
- Medicine is given by central venous access
Transient periods of sinus bradycardia and ventricular ectopy are common after termination of SVT.
Adult Dosage for Adenosine:
This medication should be delivered rapid IV push. A rhythm strip should be recorded during administration.
- The patient should be placed in a moderate reverse trendelenburg position before the drug is administered
- An initial bolus of 6mg given rapidly over 1 to 3 seconds should be given, followed by a normal saline bolus of 20mL
- The extremity in which the drug is being administered should be elevated
- A second dose of 12mg can be given in 1 to 2 minutes if needed
Directions for How to Administer Adenosine:
- Draw up the adenosine dose and saline flush in 2 separate syringes
- Attach both syringes to the IV injection port closest to the patient
- Clamp the IV tubing above the injection port
- Push IV adenosine as quickly as possible
- While maintaining pressure on adenosine plunger, push the normal saline flush as rapidly as possible after adenosine
- Unclamp IV tubing and monitor the outcome