In this episode, I’ll discuss the effects of therapeutic plasma exchange on enoxaparin half-life.
Therapeutic Plasma Exchange (TPE) or plasmapharaesis is a procedure that takes the patient’s blood and passes it through an apheresis machine, where the filtered plasma is removed and discarded with reinfusion of red blood cells along with replacement fluid such as plasma or albumin into the patient. The primary purpose of TPE is to remove an antibody, toxin, or abnormal protein in the plasma that is causing symptoms in the patient. Guillain-Barre Syndrome and hemolytic uremic syndrome are two examples of reasons a patient might undergoe TPE.
As you might expect, if the plasma also contains medications that are being used to treat another disease in the same patient, TPE might effectively remove these medications and require dose adjustment or monitoring.
A group of authors published in the American Journal of Health System Pharmacy a case in which the anti–factor Xa activity of enoxaparin was measured during therapeutic plasma exchange (TPE).
The case is that of a 52 year old man who underwent TPE for antineutrophil cytoplasmic antibody–associated vasculitis while he was receiving therapeutic enoxaparin.
The investigators measured anti-Xa activity before TPE, immediately after, and at other timepoints outside of TPE sessions.
The investigators calculated the half-life of enoxaparin to be about 315 minutes outside of TPE sessions, however it was only 54 minutes during TPE. This is a considerable change in half-life that has the potential to affect outcomes related to anticoagulation.
The authors concluded:
Enoxaparin’s anti–factor Xa activity should be monitored and dosing schedules should be adjusted to ensure therapeutic enoxaparin levels in all patients receiving TPE.
The article in this episode is a selection from my Hospital Pharmacy Academy’s weekly literature digest. Have you ever felt like your physician colleagues are one step ahead of you with new literature developments? Every week, Academy members are provided a summary curated and explained by me of the top hospital pharmacy-related articles published that week from over 20 major journals and sources to save you time and keep you up to date with the literature. To get immediate access, go to pharmacyjoe.com/academy.
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