In adult Adenosine dosing, how many times may the dose be repeated?

• A. May repeat three times
• B. May repeat one time
• C. No repeats
• D. May repeat twice

Answer: (B)

Adenosine works quickly and is given as a rapid IV bolus with a limited number of doses to maximize safety while aiming to terminate AV-nodal dependent SVT. The usual approach is to start with a 6 mg IV push; if there is no sustained response, you may administer a second dose, commonly 12 mg. You should not provide additional repeats beyond this second dose. This one-repeat limit keeps the chance of conversion high while minimizing risks such as bradycardia or AV block that can occur with multiple administrations. If the rhythm hasn’t converted after the second dose, move on to other treatments (for example, synchronized cardioversion) and continue careful monitoring. Adenosine is most effective for narrow-complex, AV node–dependent SVTs and has a very short half-life, so rapid administration is essential.