Cerebrospinal fluid neurotransmitter levels and central nervous system depression in a rat drug overdose model.

A neuropsychiatric drug overdose impairs physiological function via central nervous system (CNS) depression. In drug-related deaths, only the drug concentration can currently provide information regarding CNS depression in victims. In this study, using a drug overdose model, we investigated the ability of neurotransmitters in the cerebrospinal fluid (CSF) to serve as biomarkers for CNS depression. Four groups of rats were orally administered diazepam (200 mg/kg) and/or phenobarbital (100 mg/kg) or vehicle. In a hot plate test performed to assess physiological impairment, drug-administered animals showed prolongation of the response latency. Serum drug concentrations were also sufficient to observe the effect of drug overdose. The levels of benzoyl-derivatized neurotransmitters were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. Noradrenaline, adrenaline, serotonin, melatonin, phosphoethanolamine, and histamine levels in the CSF decreased as the response latencies in the hot plate test increased. These reduced CSF neurotransmitter levels may represent physiological dysfunction through CNS depression.

Treatment of two cases on the same day of intrathecal methotrexate overdose using cerebrospinal fluid exchange and intrathecal instillation of carboxypeptidase-G2.

BACKGROUND: Two 14-year old boys with acute lymphocytic leukemia were treated according to the NOPHO-ALL-08 protocol with intrathecal methotrexate (MTX) on the same day. Due to a preparation error in the hospital pharmacy, they were both given 240 mg of MTX instead of the prescribed 12 mg. Treatment (or methods): Both patients developed acute neurotoxicity with confusion, pain and seizures. Intravenous dexamethasone and folinic acid (leucovorin) was given. Exchange of cerebrospinal fluid was performed. Intrathecal glucarpidase (carboxypeptidase-G2) was administered after 11 h. RESULTS: One patient developed a toxic arachnoiditis. Three years after the incident, one patient has no neurological or neuropsychological sequelae after the overdose, while the other reports some loss of short-term memory. CONCLUSION: Fast recognition and treatment of intrathecal MTX overdose is critical to survival and outcome. Efforts to prevent such overdoses are of vital importance.

Successful large-volume cerebrospinal fluid aspiration for an accidental overdose of intrathecal cytarabine.

Intrathecal therapy with cytarabine is widely used in the treatment of acute lymphocytic leukemia. We report the first case of accidental intrathecal cytarabine overdose in an adult patient. Overdose of intrathecal chemotherapy has been reported to cause severe neurological damage including seizures, coma and death. Methotrexate levels can help guide intrathecal dosing of methotrexate, but no such test is commercially available for cytarabine. There are no standardized treatment recommendations for the management of this medical emergency. Intrathecal methotrexate overdose has been variously treated with cerebrospinal fluid drainage or exchange. Ventriculo-lumbar perfusion, steroids and leucovorin have also been used. It seems crucial to quickly remove as much drug as possible from the cerebrospinal fluid. Our patient was successfully treated with large-volume cerebrospinal fluid aspiration through an Ommaya reservoir. She did not suffer any significant immediate or late complications at 4 months of follow-up.

Toxicokinetics of DL-glufosinate enantiomer in human BASTA poisoning.

We found that glufosinate (DL-GLUF) was distributed in the spinal fluid in glufosinate poisoning. A 50-year old Japanese man (weighing 67 kg) attempted to commit suicide by ingesting about 100 ml of BASTA (containing DL-GLUF 18.5 g; ratio of D-GLUF to L-GLUF: 1 : 1). He was transported to our hospital, where serious respiratory depression was seen 26 h after ingestion, and management with artificial ventilation was initiated. The D-GLUF concentration 1 h after ingestion was 191.1 microg/ml, almost the same as that of L-GLUF 193.5 microg/ml, but by 3 h after ingestion, these levels had sunk to 60.3 microg/ml and 52.3 microg/ml, respectively, with the concentration of L-GLUF lower than that of D-GLUF. Later, at 27 and 35 h after ingestion, the D-GLUF level was still higher than the L-GLUF level, and the total amounts of urinary excretion were 2835 mg for D-GLUF and 2298 mg for L-GLUF, each variable thus showing a difference between the enantiomers. Cerebrospinal fluid taken from the patient 27 h after poison ingestion revealed the presence of DL-GLUF on CG-MS analysis, and quantitative HPLC analysis of the enantiomers indicated that the D-GLUF concentration was 0.48 microg/ml, and the L-GLUF concentration 0.12 microg/ml. The levels in blood collected at the same time were: D-GLUF, 1.44 microg/ml, and L-GLUF, 0.35 microg/ml. Also, the cerebrospinal fluid contained about one-third of the blood levels of both DL-GLUF enantiomers. He was discharged without any sequelae after 11 d of hospitalization.