Title |
Metabolism of levamisole and kinetics of levamisole and aminorex in urine by means of LC-QTOF-HRMS and LC-QqQ-MS
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Published in |
Analytical & Bioanalytical Chemistry, February 2013
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DOI | 10.1007/s00216-013-6829-x |
Pubmed ID | |
Authors |
Cornelius Hess, Natalie Ritke, Sebastian Broecker, Burkhard Madea, Frank Musshoff |
Abstract |
The antihelminthic drug Levamisole can enhance cocaine effects by conversion into the amphetamine-like drug aminorex. We describe an LC-MS method for the determination of levamisole and its metabolite aminorex in human urine. Selectivity is given, calibration curves were linear within the calibration range 2.5-250 ng/mL; limits of the method were LoD 0.51 ng/mL, LoQ 1.02 ng/mL for levamisole and LoD 0.65 ng/mL, LoQ 0.76 ng/mL for aminorex. Precision data was in accordance with the guidelines (intraday precision for aminorex ranged between 5.75 and 11.0 % for levamisole between 8.36 and 10.9 %; interday precision for levamisole 10.9-16.9 % and for aminorex 7.64-12.7 %; accuracy data for levamisole -1.96 to -14.3 % and for aminorex-11.9 to-18.5 %). The validated method was successfully applied to study the urinary excretion of levamisole after the administration of 100 mg of levamisole orally. Levamisole and aminorex could be detected in post-administration urine samples. Levamisole could be detected up to 39 h after ingestion, while aminorex was detectable up to 54 h. Maximum aminorex concentrations were 45 ng/mL urine. Further metabolites of levamisole after oral ingestion by means of liquid chromatography hybrid quadrupole time-of-flight high-resolution mass spectrometry (LC-QTOF-HRMS) were identified. Only 0.5 % of the ingested drug was quantified as unchanged levamisole in urine. Besides aminorex, five isomers of aminorex and 4 hydroxy-metabolites of aminorex or its isomers were found. Furthermore, levamisole is also hydroxylated and eliminated free or conjugated with sulfate or glucuronide into urine. |
Mendeley readers
Geographical breakdown
Country | Count | As % |
---|---|---|
Unknown | 40 | 100% |
Demographic breakdown
Readers by professional status | Count | As % |
---|---|---|
Student > Master | 8 | 20% |
Researcher | 8 | 20% |
Student > Bachelor | 5 | 13% |
Student > Ph. D. Student | 4 | 10% |
Student > Doctoral Student | 3 | 8% |
Other | 6 | 15% |
Unknown | 6 | 15% |
Readers by discipline | Count | As % |
---|---|---|
Chemistry | 9 | 23% |
Medicine and Dentistry | 7 | 18% |
Pharmacology, Toxicology and Pharmaceutical Science | 6 | 15% |
Nursing and Health Professions | 2 | 5% |
Agricultural and Biological Sciences | 2 | 5% |
Other | 5 | 13% |
Unknown | 9 | 23% |