Continuous infusion of obidoxime and the importance of plasma levels monitoring in the organophosphate poisoning

The aim of this prospective study is to validate the continuous intravenous perfusion of obidoxime in the treatment of intoxication with organophosphate insecticides. Five patients intoxicated with organophosphate insecticides showing suicidal purposes were studied. Besides the classical treatment in such cases, the antidote (obidoxime) was administrated by an initial bolus followed by continuous infusion during 48-96 hours. Different drug plasma levels were found in spite of the same dosage regimens. We used the method of chromatographic analysis by HPLC-UV to quantify the obidoxime plasma levels of the intoxicated patients. Toxic levels were found in two cases with hepatocellular dysfunction preceded by renal impairment. Close monitoring in order to readjust the therapeutic doses and larger studies are needed to establish the optimal dosage regimens.