The antispasmodic drug mebeverine leads to positive amphetamine results by fluorescence polarization immunoassay (FPIA)--studies on the toxicological analysis of urine by FPIA and GC-MS.
Mebeverine (Duspatal, MB), an antispasmodic drug, is the veratric acid ester of 4-[ethyl-[2-(4-methoxyphenyl)-1-methylethyl]amino]butan-1-ol (MB-OH), which is a N-substituted ethylamphetamine derivative. MB is metabolized via ester hydrolysis to MB alcohol (MB-OH) and veratric acid. N-Dehydroxybutylation leads to methoxyethylamphetamine (MO-EA) and, after O-demethylation, to hydroxy EA (HO-EA). N-Bisdealkylation leads to p-methoxyamphetamine (PMA). MO-EA and PMA are also known as designer drugs. Fluorescence polarization immunoassay (FPIA) and gas chromatographic-mass spectrometric studies on the toxicological analysis of MB after ingestion of a single 405-mg oral dose of MB were performed. We could show that intake of MB leads to positive FPIA results for amphetamine. The N-dehydroxybutyl metabolites of MB, MO-EA, HO-EA, and the bis-dealkyl metabolite PMA should be responsible for the positive immunoassay results. Using our systematic toxicological analysis procedure, every positive amphetamine immunoassay could be explained by detection of MO-EA, HO-EA, and/or PMA. Misinterpretation of the origin of MO-EA, HO-EA, or PMA can be avoided by detecting the specific (non-dehydroxybutylated) metabolites of MB, which are excreted for a much longer time after ingestion.
Kraemer
T
T
Department of Toxicology, University of Saarland, Homburg, Germany. pttkra@med-rz.uni-sb.de
Wennig
R
R
Maurer
H H
HH
D000661:Amphetamine / Q000737:chemistry* / Q000652:urine; D000927:Anticonvulsants / Q000737:chemistry* / Q000652:urine; D005189:False Positive Reactions; D016231:Fluorescence Polarization Immunoassay; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D008297:Male; D010627:Phenethylamines / Q000737:chemistry* / Q000652:urine; D012680:Sensitivity and Specificity; D015813:Substance Abuse Detection / Q000379:methods*
D000927:Anticonvulsants; D010627:Phenethylamines; C005096:mebeverine; D000661:Amphetamine