Kinetics of pesticide degradation by human fresh frozen plasma (FFP) in vitro

Abstract There is an ongoing debate about the benefit of fresh frozen plasma (FFP) infusion in organophosphorus (OP) pesticide-poisoned patients. This prompted us to investigate the kinetics of OP pesticide degradation by FFP with an enzymatic assay in vitro . Degradation was rapid with shortest half-lives of 19.5 s for chlorpyrifos-oxon, 6.3 min for paraoxon-ethyl and 17.9 min for dichlorvos. Heptenophos (78.0 min), mevinphos (101.8 min), profenofos (162.3 min) and malaoxon (179.7 min) showed half-lives of up to 3 h. Substantial longer degradation half-lives of 69.7–80.8 h were determined with chlorfenvinphos and bromfenvinphos. Methamidophos and omethoate showed no degradation by FFP indicated by half-lives similar to spontaneous hydrolysis. In conclusion, degradation by FFP depends on the particular OP pesticide and the used FFP batch.