Determination of Levamisole in Urine by Gas Chromatography-Mass Spectrometry

U.S. FDA/CDER/DPA, 1114 Market Street, St. Louis, Missouri 63101, USA.
Journal of analytical toxicology (Impact Factor: 2.86). 10/2011; 35(8):545-50. DOI: 10.1093/anatox/35.8.545
Source: PubMed


The United States Public Health Service Substance Abuse and Mental Health Services Administration is alerting medical professionals that a substantial percentage of cocaine imported into the United States is adulterated with levamisole, a veterinary pharmaceutical that can cause blood cell disorders such as severe neutropenia and agranulocytosis. Levamisole HCl is the active ingredient in a number of veterinary drugs approved to treat worm infestations in animals. Levamisole HCl was also the active ingredient in a human drug for oral administration approved on June 18, 1990, as adjuvant treatment in combination with fluorouracil after surgical resection in patients with Duke's stage C colon cancer. This drug was withdrawn from the U.S. market around 2000, and it has not been marketed in the U.S. since then. The objective of this study was to develop a method to determine the amount of levamisole in urine samples. The procedure will be provided to state health laboratories as needed to be used in the evaluation of patients that have developed neutropenia or agranulocytosis in the setting of recent cocaine use. A gas chromatography-mass spectrometry method was validated and tested at two different laboratories, and the method limit of detection for levamisole is 1 ng/mL in urine when using a 5-mL sample. Confirmation of the stereoisomer of levamisole was done by high-performance liquid chromatography using a chiral column.

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Available from: Michael L Trehy, Jan 06, 2016
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    ABSTRACT: Abstract Levamisole is an anthelminthic that was first used as a de-worming agent in humans and animals. It has also been used to treat inflammatory conditions as well as certain types of cancer. Levamisole was discontinued for human use in the early 21st century due to toxic side effects including agranulocytosis and vasculitis. Recently, levamisole was discovered as a cocaine adulterant after reports emerged of drug users with the above disorders. As the prevalence of cocaine usage has grown in the last 15 years, measurement of levamisole in human samples has become increasingly important. This review focuses on the various bioanalytical methods available for the determination of levamisole in human plasma and urine. Earlier methods employed gas chromatography coupled with nitrogen-selective thermionic specific detection and nitrogen-phosphorus detection, as well as high performance liquid chromatography coupled with ultraviolet detection. In addition, gas chromatography-mass spectrometry (GC-MS) and high performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) have also been described. Currently, GC-MS appears to be the method of choice however recent developments in the area of LC-MS/MS make this technology an attractive alternative. The merits of both GC-MS and LC-MS/MS for the determination of levamisole are evaluated on the basis of sample preparation, chromatographic separation conditions, run time, and analytical performance. In addition, emerging methods in this area are also reviewed.
    No preview · Article · Nov 2012 · Clinical Chemistry and Laboratory Medicine

  • No preview · Article · Nov 2012 · Case Reports
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    ABSTRACT: Study objective: To characterize the demographic, clinical, and epidemiologic features of levamisole-associated neutropenia in cocaine or heroin users. Methods: State health departments were recruited for participation when the Centers for Disease Control and Prevention (CDC) was notified of potential cases by a clinician, a health department official, or a poison center between October 15, 2009, and May 31, 2010. A case was defined as a person with an absolute neutrophil count less than 1,000 cells/μL (or a WBC count <2,000 cells/μL) and a self-reported history or laboratory confirmation of cocaine or heroin use. Health department officials abstracted data from medical charts, attempted a patient interview, and submitted data to CDC for descriptive analysis. Results: Of the 46 potential cases reported from 6 states, half met eligibility criteria and had medical chart abstractions completed (n=23; 50%). Of these, close to half of the patients were interviewed (n=10; 43%). The average age was 44.4 years; just over half were men (n=12; 52%). The majority of patients presented to emergency departments (n=19; 83%). More than half presented with infectious illnesses (n=12; 52%), and nearly half reported active skin lesions (n=10; 44%). The majority of interview respondents used cocaine greater than 2 to 3 times a week (n=9; 90%), used cocaine more than 2 years (n=6; 60%), and preferred crack cocaine (n=6; 60%). All were unaware of exposure to levamisole through cocaine and of levamisole's inherent toxicity (n=10; 100%). Conclusion: Physicians should suspect levamisole exposure in patients using illicit drugs, cocaine in particular, who present with unexplained neutropenia. Most patients reported chronic cocaine use and were unaware of levamisole exposure. Cocaine use is more prevalent among men; however, our results identified a higher-than-expected proportion of female users with neutropenia, suggesting women may be at higher risk. Emergency physicians and practitioners are uniquely positioned to recognize these patients early during their hospital course, elucidate a history of cocaine or other drug exposure, and optimize the likelihood of confirming exposure by arranging for appropriate drug testing.
    No preview · Article · Jan 2013 · Annals of emergency medicine
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