Interesting couple of pearls today regarding adenosine boluses for treatment of SVT courtesy of Bryan Hayes (@PharmERToxGuy). Standard dose is 6mg followed by 12mg, except under certain circumstances:
- The ingestion of caffeine prior to an adenosine bolus significantly reduces its effectiveness in treating SVT. If your patient just finished a triple espresso a few hours ago, consider starting with 12mg and escalating to 18mg (Remember, caffeine = adenosine receptor blocker).
- Consider lowering your initial dose of adenosine when given centrally to 3mg/6mg/6mg. A case report (below) highlights an episode of prolonged (13s) bradycardia and severe side effects when given at a full dose centrally.
- Cabalag MS, Taylor DM, Knott JC, Buntine P, Smit D, Meyer A. Recent caffeine ingestion reduces adenosine efficacy in the treatment of paroxysmal supraventricular tachycardia. Acad Emerg Med. 2010 Jan;17(1):44-9. Epub 2009 Dec 9.
- Chang M, Wrenn K. Adenosine dose should be less when administered through a central line. J Emerg Med. 2002 Feb;22(2):195-8.