Inhibitor Report for: Mecarbam

Nine human acute poisonings due to intentional ingestion of organophosphorous pesticides are presented. Six of the victims died. Six patients were treated in the Intensive Care Unit (ICU) from 34 h to 45 d, while 3 were found dead by relatives. Two of the patients treated in the ICU fully recovered after 15 and 24 d while the third survivor developed delayed neuropathy. Organophosphate blood levels were determined on admission and during therapy, and in 1 case atropine and pralidoxime levels were also detected. Significant fluctuations of the plasma cholinesterase activity were observed during therapy. Postmortem analysis revealed higher levels of pesticides in organs (eg 23.1 micrograms fenthion/g kidney) and in fat (135.2 micrograms fenthion/g) than in blood (eg 4.8 micrograms fenthion/ml) and vitreous humor. Considerable pesticide was measured in testis (eg 5.8 micrograms fenthion/g, 0.8 micrograms methidathion/g) and uterus (170.5 micrograms malathion/g). Extracorporeal decontamination to enhance pesticide elimination is a therapeutic challenge.

The persistence of eight granular organophosphorus insecticides in one loam-type soil was studied in both laboratory experiments under controlled conditions and in outdoor experiments, by comparison of disappearance curves in semi-logarithmic co-ordinate systems. The pesticides studied were: Aphidan (O,O-di-isopropyl-S-ethyl-sulphinyl methyl dithiophosphate), bromophos, chlorfenvinphos, dichlo- fenthion, dimethoate, mecarbam and trichloronate. The comparisons confirm that a strict control of several parameters (e.g. water content of the soil and temperature) is needed for the quantitative description of disappearance rates. However, a reasonably good agreement in the relative order of persistence was found in the experiments and a tentative classification of the eight insecticides according to degree of persistence in the soil is suggested. Metabolites were found to be present in the soil from two of the compounds, but the contributions to total residues and, accordingly, the influence on persistence evaluation from these were not included owing to lack of definite identifications and finalised determinations.

Nine human acute poisonings due to intentional ingestion of organophosphorous pesticides are presented. Six of the victims died. Six patients were treated in the Intensive Care Unit (ICU) from 34 h to 45 d, while 3 were found dead by relatives. Two of the patients treated in the ICU fully recovered after 15 and 24 d while the third survivor developed delayed neuropathy. Organophosphate blood levels were determined on admission and during therapy, and in 1 case atropine and pralidoxime levels were also detected. Significant fluctuations of the plasma cholinesterase activity were observed during therapy. Postmortem analysis revealed higher levels of pesticides in organs (eg 23.1 micrograms fenthion/g kidney) and in fat (135.2 micrograms fenthion/g) than in blood (eg 4.8 micrograms fenthion/ml) and vitreous humor. Considerable pesticide was measured in testis (eg 5.8 micrograms fenthion/g, 0.8 micrograms methidathion/g) and uterus (170.5 micrograms malathion/g). Extracorporeal decontamination to enhance pesticide elimination is a therapeutic challenge.

Only a small number of organophosphorous compounds, of the many thousands circulating on the market, has been reported as causing neuropathy with delayed onset. A case is presented of a young male who in an attempt to commit suicide by taking a massive dose of Mecarbam, developed polyneuropathy accompanied by a mild involvement of the CNS. Mecarbam is herewith reported for the first time as an agent which can affect the peripheral nervous system.

A suicidal poisoning committed by a 19-year-old pregnant woman, who ingested an unknown quantity of an aqueous solution mecarbam (trade name includes 'Murfotox') containing 68 g/l of S-(N-ethoxycarbonyl-N-methylcarbamoyl methyl) O,O-diethyl phosphorodithioate (C.R. Worthing (Ed.), The Pesticide Manual, 6th end, BCPC, 1980) is described. The pesticide crossed the placental barrier and caused the death of the fetus. Toxicologic analysis of mecarbam in several tissues and fluids of mother-fetus revealed its distribution. The analysis was performed by thin-layer chromatography (TLC) and gas-liquid chromatography (GC). The case described serves to point out the ease with which mecarbam crossed the placental barrier, its high concentration in the lungs and the considerably higher concentrations in fetal than in mother's tissues.

The persistence of eight granular organophosphorus insecticides in one loam-type soil was studied in both laboratory experiments under controlled conditions and in outdoor experiments, by comparison of disappearance curves in semi-logarithmic co-ordinate systems. The pesticides studied were: Aphidan (O,O-di-isopropyl-S-ethyl-sulphinyl methyl dithiophosphate), bromophos, chlorfenvinphos, dichlo- fenthion, dimethoate, mecarbam and trichloronate. The comparisons confirm that a strict control of several parameters (e.g. water content of the soil and temperature) is needed for the quantitative description of disappearance rates. However, a reasonably good agreement in the relative order of persistence was found in the experiments and a tentative classification of the eight insecticides according to degree of persistence in the soil is suggested. Metabolites were found to be present in the soil from two of the compounds, but the contributions to total residues and, accordingly, the influence on persistence evaluation from these were not included owing to lack of definite identifications and finalised determinations.