In this episode, I’ll discuss why the adenosine dose is reduced by 50% when it is given in a central line.
The recommendation to reduce the initial dose of adenosine from 6 mg to 3 mg and follow-up doses from 12 mg to 6 mg when it is given in a central line is in the ACLS guidelines but not the adenosine prescribing information.
This dose adjustment is recommended out of concern for bradycardia and other severe hemodynamic side effects when the regular dose is given via a central line. Evidence of these side effects is limited to case reports.
However, the lower dose has been shown to be as effective when given via a central line as the higher dose given peripherally. Supporting data comes from a 1993 dose-finding safety and efficacy study for adenosine which compared doses of 3, 6, 9, and 12 mg in peripheral and central lines. In the peripheral line group, tachycardia was terminated in 70% of patients who got 6 or less mg of adenosine. In the central line group, tachycardia was terminated in 70% of patients who got 3 mg of adenosine.
In this study, there was no difference between the two routes of drug administration in the incidence of side effects or transient arrhythmias at the time of tachycardia termination.
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Thanks for the info once again… I recently had a case where Adenosine was given in patient with EF < 15%. Interestingly the medication has zero effect. And when I say zero, I mean Zero. The patient felt nothing, no change in vitals or subjective effect. I had RN validate the line and tried subsequent doses via other lines that were working well. Your post made me think about that and wonder if given the rapid t1/2 if pts with very poor EFs/severe heart failure have different responses to particularly the lower recc doses? I wonder if others have noticed similar outcomes in pts with very low EFs or if this was just an outlier? Again the lines were working well….
Thanks again for continueing to push great clin pharm content. Appreciate it.
Ash
Hi Ash! That is an interesting case and your explanation sounds plausible. There have been a handful of times I’ve experienced adenosine having no effect for a patient but I cannot recall if those patients had a low EF or not. Also, thanks for the kind words!