Urinary excretion kinetics of methylamphetamine in man

Beckett, A. H.; Rowland, M.

doi:10.1111/j.2042-7158.1965.tb07757.x

Cited by 78 publications

(28 citation statements)

References 8 publications

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“…The transfer of MAMP and AMP into the hair is not known minutely. However, from the studies of the transfer into urine (Dring et al [18], Beckett et al [19] and Caldwell et al [5]) and the reports concerning hair by Ishiyama et al [20], Niwaguchi et al [21] and Suzuki et al [22], we know that excretion rates into urine and hair are quite different, and the optical isomers may not be converted in vivo. We suggest that both abusers tested in the present study abused d-MAMP.…”

Section: Discussionmentioning

confidence: 90%

Forensic toxicologic analysis of methamphetamine and amphetamine optical isomers by high performance liquid chromatography

Nagai

Kamiyama

1988

Z Rechtsmed

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Optical isomers (d and l) and racemic compounds (dl) of methamphetamine (MAMP) and amphetamine (AMP), and biologic materials including those substances, could be analyzed by high performance liquid chromatography. Examining the temperature for the analysis, 40 degrees C was the optimal condition in the reproducibility of separated MAMP-isomers. The reproducibility at the temperature did not vary significantly. The measured values of optical isomers were 0.116 +/- 0.012, 1.082 +/- 0.070 and 8.984 +/- 0.136 for the mixing ratios (l/d) of 0.111, 1.000, and 9.000, respectively. The detection limit for both d- and l-isomers was 25 ng. The analytic result of hair specimens from two stimulant abusers by the present method indicates that they contained only d-MAMP and d-AMP, which is believed to have the strongest pharmacologic effect among the optical isomers of MAMP. The coefficient of variation in the analysis of five replicate standards, prepared by adding 1,000 ng each of racemate MAMP and AMP to hair, was less than 4%. The measured value against l/d = 1.000 was 1.040 +/- 0.040 in MAMP and 0.980 +/- 0.030 in AMP. The detection limit for both racemate MAMP and AMP accumulated in hair was 250 ng. The analysis of the optical isomers by our method would contribute to identifying the smuggling routes or the illicit method.

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Section: Discussionmentioning

confidence: 90%

Forensic toxicologic analysis of methamphetamine and amphetamine optical isomers by high performance liquid chromatography

Nagai

Kamiyama

1988

Z Rechtsmed

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“…The reason for the degree of N-demethylation of S()-MP into the corresponding enantiomer of AP being higher than that of its antipode is unclear. However, it has been reported that the N-demethylation of MP in the human body is an enantiomer-specific metabolic process and the ratios of AP/MP excreted in urine 24 h after an oral dose of 13.7 mg of individual MP enantiomers (n = 3) were 17.8 AE 3.0 and 5.2 AE 1.1% for the S()-and the R(À)-enantiomers, respectively (Beckett and Rowland, 1965). These results are in agreement with our results.…”

Section: Resultsmentioning

confidence: 99%

“…S()-MP hydrochloride was obtained from Dainippon Pharmacy (Osaka, Japan) and R(À)-MP was kindly supplied by Dr S. Ikeda, Kyushu District Narcotics Central Office, Ministry of Health and Welfare, Japan. AP sulfate and p-HMP hydrochloride racemates were synthesized in our laboratory according to known procedures (Nagai, 1893;Buzas and Dufour, 1950). S()-AP and R(À)-AP were a kind gift from Professor T. Nagano, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Japan.…”

Section: Methodsmentioning

confidence: 99%

Enantiomer-specific high-performance liquid chromatography with fluorescence detection of methamphetamines in abusers' hair and urine

Al-Dirbashi

Wada

Kuroda

et al. 1999

Biomed. Chromatogr.

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Enantiomer‐specific high‐performance liquid chromatography with fluorescence detection using 4‐(4,5‐diphenyl‐1H‐imidazol‐2‐yl)‐benzoyl chloride as a fluorescence labeling reagent was applied to determine methamphetamine and its metabolites in abusers’ hair and urine. Hair samples were segmentally analyzed based on 1 cm long segments. In four hair samples, only the S(+)‐enantiomers of methamphetamine and its N‐demethylated metabolite, S(+)‐amphetamine were detected. Satisfactory correlation (r = 0.901) between the results of high‐performance liquid chromatography‐fluorescence and those of gas chromatography‐nitrogen phosphorous detection was obtained (n = 19). In an abuser's urine sample, the S(+)‐ and R(−)‐enantiomers of methamphetamine, amphetamine and para‐hydroxymethamphetamine were detected. The degree of N‐demethylation of S(+)‐methamphetamine into the corresponding metabolite of amphetamine was significantly higher than that of the R(−)‐enantiomer. Copyright © 1999 John Wiley & Sons, Ltd.

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“…While the major route of elimination for methamphetamine (15,16) and ethylamphetarnine (11), under controlled acidic urinary conditions, is the excretion of the unchanged drug, only 1.5% of orally administered mefenorex was excreted unchanged. Increased metabolism of mefenorex may be associated with the increased lipophilicity of the nitrogen substituent.…”

Section: Resultsmentioning

confidence: 99%

“…Extensive studies on urinary excretion of the unchanged drug and metabolite amphetamine have been made after oral administration of the (+) and/or (-) isomers of N-alkylamphetamines (methyl-, ethyl-, n-propyl-, i-propyl, and n-butyl-) (15,17,18,20). However data on racemic N-alkylamphetamines are insufficient for comparison with those obtained in the present study.…”

Section: Resultsmentioning

confidence: 99%

Urinary excretion and metabolism of orally administered mefenorex

Rendić

Slavica

Medić-Šarič

1994

Eur. J. Drug Metab. Pharmacokinet.

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Metabolic pathways and the pharmacokinetic profile of mefenorex «±)N-(3-chloropropyl)-1-methyl-2-phenylethylamine), and its main metabolite amphetamine (l-methyl-2-phenylethylamine) have been studied in two healthy volunteers, after a single oral dose of mefenorex (1.2 mglkg body weight for a male subject and 2.4 mglkg body weight for a female subject). Urinary concentrations were determined by gas chromatography (GC) and metabolite structure was identified by GCJMS following derivatization of urine extracts. The ratio of this metabolite to unchanged drug in urine samples, collected up to 5 h following administration, was essentially the same after either of the administered doses.The calculated KeI for mefenorex after the higher dose was in the range of 0.191-0.272 h-I, with a biological half life (tm) of 3.98-2.55 h, depending on the method of calculation used. The elimination of amphetamine was much slower with a Kel ranging from 0.039-0.073 h-I and a tIn from 9.5-17.8 h. Depending on the dose administered, the rate constant of metabolite formation was 0.129 and 0.685 h-I for low and high doses, respectively.Urinary excretion of Rondimen S amounted to 11.9% within 72 h after administration. Of this amount, 1.5% represented unchanged drug and 10.4% represented metabolites. In addition to amphetamine 3 other metabolites were identified: p-hydroxy mefenorex, p-hydroxy amphetamine and p-hydroxy-m-methoxy mefenorex.

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Urinary excretion kinetics of methylamphetamine in man

Cited by 78 publications

References 8 publications

Forensic toxicologic analysis of methamphetamine and amphetamine optical isomers by high performance liquid chromatography

Forensic toxicologic analysis of methamphetamine and amphetamine optical isomers by high performance liquid chromatography

Enantiomer-specific high-performance liquid chromatography with fluorescence detection of methamphetamines in abusers' hair and urine

Urinary excretion and metabolism of orally administered mefenorex

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