bialaphos and Organophosphate-Poisoning

The symptoms of acute poisoning caused by ingestion of bialaphos (BIAL), an ingredient of herbicide, are supposed to be due to the L-glufosinate (L-GLUF), which is formed by the degradation of bialaphos. To elucidate the pharmacokinetics of BIAL and L-GLUF, we attempted a simultaneous analysis of BIAL and L-GLUF in biological samples by exploiting a reversed phase HPLC method. The derivatization reaction of BIAL and L-GLUF using (+) -1- (9-fluorenyl) ethyl chloroformate was completed in 30 min at 40 degrees C and both derivatives were stable for 48 hr at 25 degrees C. A fluorescence detector were used for HPLC; the exicitation wavelength was set at 265 nm and the emission wavelength at 315 nm. Respective calibration curves prepared by adding BIAL and L-GLUF to serum were linear within ranges of 0.01-10.0 and 0.005-10.0 microg/mL in derivatived liquid samples for introducing into HPLC. The lower limits of detection for BIAL and L-GLUF were 0.005 and 0.001 microg/mL, respectively. An 83-year old male who ingested approximately 350 mL of Herby Liquid, a herbicide containing 18% BIAL and 82% surfactant, in an attempt to commit suicide developed delayed respiratory depression and seizures. L-GLUF was detected in the serum of the patient 2.7 hr after ingestion, but BIAL was not. The change in serum L-GLUF concentration measured over time was consistent with a 2-compartment model, with a distribution half-life of 1.70 hr and an elimination half-life of 6.03 hr.

Topics: Aged, 80 and over; Aminobutyrates; Chromatography, High Pressure Liquid; Herbicides; Humans; Male; Organophosphate Poisoning; Organophosphorus Compounds; Specimen Handling; Suicide, Attempted; Time Factors

A 47-year-old Japanese woman undergoing maintenance hemodialysis (HD) was admitted to our hospital because of poisoning with the herbicide bialaphos. Respiratory arrest and loss of consciousness ensued rapidly, accompanied by convulsions and nystagmus. Treatment with HD and direct hemoperfusion, followed by HD alone, effectively removed bialaphos and its chief toxic metabolite (L-AMPB) from the circulation (bialaphos decreased from 0.33 to < 0.05 microg/ml and L-AMPB from 14 to 0.86 microg/ml). The glutamate concentration improved gradually after the removal of bialaphos and L-AMPB from plasma (plasma glutamate concentration: 250.4 nmol/l on day 5 to 120.6 nmol/l on day 26). Decreased glutamine concentration in cerebrospinal fluid was demonstrated for the first time as well as in plasma, indicating glutamine synthetase inhibition not only in plants but also in humans by bialaphos poisoning.

Topics: Adult; Female; Glutamic Acid; Glutamine; Herbicides; Humans; Japan; Organophosphate Poisoning; Organophosphorus Compounds; Renal Dialysis; Respiratory Distress Syndrome; Seizures; Unconsciousness

A 64-year-old man with ethanol intoxication, ingested a bottle of Herbiace (100 ml, 32 w/v% of bialaphos, CAS #35597-43-4, Meiji Seika Kaisha, Tokyo, Japan). He had severe metabolic acidosis and was treated with infusions of sodium bicarbonate and furosemide, plus gastric lavage and enema. The metabolic acidosis improved 15 hours after treatment but nystagmus, apnea and convulsions were progressive. Although his sensorium was clear, spontaneous respirations were not observed for 64 hours. The electroencephalographic findings of atypical triphasic waves and slow waves suggest a unique response to bialaphos poisoning. His clinical course indicates that the management of apnea is critically important to recovery from bialaphos poisoning.

Topics: Acidosis; Alcoholic Intoxication; Apnea; Electroencephalography; Herbicides; Humans; Male; Middle Aged; Nystagmus, Pathologic; Organophosphate Poisoning; Organophosphorus Compounds; Poisoning; Seizures