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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