Bioanalytical methods for quantitation of levamisole, a widespread cocaine adulterant

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 chromatographymass 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.

An Extensive Comparison of the Effect of Anthelmintic Classes on Diverse Nematodes

“…I8898), pyrantel tartrate, (catalog no. P7674; chosen over the other nAChR agonist, levamisole, because levamisole has toxic side effects that has resulted in it being withdrawn for use in human health in a number of places, including the United States and Canada [27]), and dimethyl sulfoxide (DMSO) (catalog no. D8418) were purchased from Sigma-Aldrich.…”

Amperometric flow-injection determination of the anthelmintic drugs ivermectin and levamisole using electrochemically pretreated boron-doped diamond electrodes

“…Other properties of LVM have also been recognized and, thus, it has been used as an adjuvant drug in the treatment of colon cancer and as an immunomodulator; more recently, LVM has been identified as a cocaine adulterant that might have toxic effects [15,16].…”

“…Numerous methods have also been described in the literature for the determination of LVM, but mainly using chromatographic techniques coupled with different detectors [16,19,20]. However, as far as we could ascertain, there are only two electroanalytical methods described for the determination of this drug, as reviewed next.…”

Poisoning of a child by levamisole: Evidence by hair testing

“…In the literature, various bioanalytical methods for the determination of levamisole in human plasma and urine have been described and they were summarized by Shea et al [8]. Furthermore, few hair testing methods were published, always in combination with cocaine [7,[9][10][11].…”