Adenosine

Adult Dosing

• 6mg rapid IV bolus over 1-2s
  • If ineffective can try 12mg 2min later
    • If still ineffective can try another 12mg
• Caveat
  • Higher dose (1st 12mg, 2nd/3rd 18mg) in pt taking methylxanthines (ie caffeine, theophylline)
    • Blocks adenosine binding at receptor sites (competitive antagonist)
  • Lower dose (1st 3mg, 2nd/3rd 6mg) in pt taking carbamazepine (Tegretol), diazepam (Valium) or dipyridamole (Persantine) OR with a heart transplant.

Contraindications

• 2nd, 3rd AV block
• Sick sinus syndrome
• Reentrant SVTs not involving AV node are not terminated
• No effect on anterograde WPW

Indications

• Conversion of reentrant PSVT to NSR

Mechanism of Action

• Negative inotropic, dromotropic, chronotropic effects
• Transient AV nodal block

Adverse Drug Rxns

• Bronchoconstriction (responds to bronchodilators)
• Bradyarrhythmia
• Hypotension (if given too slowly)

Kinetics

Onset of action = 20-30s Duration of action = 60-90s

See Also

Antiarrhythmics