Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0028738 (nystagmus)
 7,431 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A simple liquid-liquid extraction procedure for the analysis of gamma-hydroxybutyrate (GHB) in biological fluids without conversion to its lactone, gamma-butyrolactone, is described. Following derivatization to its di-TMS derivative, GHB was detected using gas chromatography-electron impact mass spectrometry. Diethylene glycol was used as the internal standard. The limit of quantitation in 1 mL of blood was 1 mg/L, and a linear response was observed over the concentration range 1 to 100 mg/L. Coefficients of variation for both intra-assay precision and interassay reproducibility ranged between 3.9 and 12.0%. GHB was detected in the blood of a sexual assault victim (3.2 mg/L), in the blood of two driving (DUI) cases (33 and 34 mg/L), and in the blood and urine of two nonfatal GHB-overdose cases (blood 130 and 221 mg/L; urine 1.6 and 2.2 g/L). The observed clinical symptoms ranged from confusion, disorientation, vomiting, and nystagmus to ataxia, sinus bradycardia, unconsciousness, and apnea.
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PMID:Determination of gamma-hydroxybutyrate (GHB) in biological specimens by gas chromatography--mass spectrometry. 1065 61

Topiramate (Topamax), an effective seizure disorder treatment, received additional FDA approval for prevention of migraine headaches in August 2004 and has gained attention for its off-label uses, including psychiatric and eating disorders, neuropathic pain, and alcohol and drug dependency. Side effects of sedation, dizziness, ataxia, speech difficulty, nystagmus, paresthesia, and metabolic acidosis are described. The manufacturer reports that tolerance to the antiseizure properties does not develop. With its established efficacy for epilepsy treatment and its increased use for other disorders, topiramate-positive findings are more common in death-investigation and human-performance casework. To evaluate the role of topiramate, we reviewed all topiramate-positive cases from our laboratory between 1998 and 2004, which constituted 132 cases (63 death investigations, 68 suspected impaired drivers, and 1 sexual assault case). The subjects were predominantly female (69%) with a mean and median age of 42. Blood topiramate concentrations ranged from 1 to 180 mg/L (median 6.4 mg/L, mean 8.4 mg/L), and 94% were positive for at least one additional drug. There was evidence of psychomotor impairment in some drivers with blood concentrations within the normal therapeutic range, and deaths attributed to topiramate alone occurred at concentrations as low as 50 mg/L.
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PMID:Topiramate-positive death-investigation and impaired-driving cases in Washington State. 1713 58