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Drug Monitoring and Toxicology: Jonathan M. Oyler, Edward J. Cone, Robert E. Joseph, Jr, Eric T. Moolchan, and Marilyn A. Huestis Duration of Detectable Methamphetamine and Amphetamine Excretion in Urine after Controlled Oral Administration of Methamphetamine to Humans Clin Chem 2002; 48: 1703-1714 [Abstract] [Full text] [PDF]

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Prevalence of d-Methamphetamine mixed with l-Methamphetamine in Japan

Toshio Okazaki, Toshiaki Nagai, Masayoshi Amemiya, and Tatsuo Nagai   (13 August 2003)

Mixture of DMAMP in MAMP Tablet

Toshio Okazaki, Masayoshi Amemiya, Tatsuo Nagai   (3 July 2004)

Prevalence of d-Methamphetamine mixed with l-Methamphetamine in Japan 13 August 2003
Toshio Okazaki, Ph.D., Associate Professor Kitasato University, Toshiaki Nagai, Masayoshi Amemiya, and Tatsuo Nagai Send letter to journal: Re: Prevalence of d-Methamphetamine mixed with l-Methamphetamine in Japan okazaki{at}cc.ahs.kitasato-u.ac.jp Toshio Okazaki, et al.	Prevalence of d-Methamphetamine mixed with l-Methamphetamine in Japan   Dear Editor: Oyler et al. (1) reported the appearance of amphetamine (AMP) in urine after oral administration of methamphetamine (MAMP). Analysis of the pattern of time-course changes in the AMP level excreted in urine after ingestion of MAMP is important prior to the administration of MAMP. Although use of MAMP is strictly controlled by law in Japan, a large amount of MAMP is smuggled especially from North Korea. Suspects of use of MAMP are arrested when the presence of MAMP and its metabolite, AMP, is demonstrated in the urine. However, in recent years, not only d-MAMP but also its optical isomer, l-MAMP, has been frequently seized in Japan (Table 1). Since seized drugs contained diversely mixed crystals of d-MAMP and l-MAMP, sellers may have mixed purified d-MAMP and l-MAMP and recrystallized the mixture before selling it. The metabolic rates of d-MAMP and l-MAMP are different (2), and difference in the mixing ratio may greatly affect the detection rate and earlier detection of urinary AMP. This is a serious problem in combating stimulant drugs in Japan. REFERENCES 1.Oyler JM, Cone EJ, Joseph RE JR, Moolchan ET, Huestis MA. Duration of detectable methamphetamine and amphetamine excretion in urine after controlled oral administration of methamphetamine to humans. Clin Chem 2002;48:1703-14. 2.Nagai T, Kamiyama S. Simultaneous HPLC analysis of optical isomers of methamphetamine and its metabolites, and stereoselective metabolism of racemic methamphetamine in rat urine. J Anal Toxicol 1991;15:299-304 Table Legend Table 1 MAMP-optical isomers seized in Saitama Prefecture in Japan   Optical Isomers 1998 2000 2002 d-MAMP 46 (77%) 72 (65%) 51 (81%) d-MAMP and l-MAMP 10 (17%) 35 (32%) 12 (19%) l-MAMP 4 (7%) 3 (3%) 0 (0%)
Mixture of DMAMP in MAMP Tablet 3 July 2004
Toshio Okazaki, Associate Professor Kitasato University, Masayoshi Amemiya, Tatsuo Nagai Send letter to journal: Re: Mixture of DMAMP in MAMP Tablet okazaki{at}cc.ahs.kitasato-u.ac.jp Toshio Okazaki, et al.	Dear Editor: Oyler J. M. et al. (1) performed oral administration of methamphetamine (MAMP), one of the most common illicit drugs, and evaluated the excretion patterns of MAMP and AMP in the urine. In recent years, d-MAMP/l-MAMP mixture drugs have been increasing in Japan (2). We developed a method of determining the d/l ratio in MAMP used by arrested drug abusers based on the pattern of serial changes in the d- MAMP/l-MAMP ratio excreted into the urine after intake of MAMP drugs that differ in the mixture ratio of the optical isomers (3). In addition, we observed mixture of dimethylamphetamine (DMAMP) as a stimulant in urine samples of 24 of 209 stimulant abusers arrested since 1998. Oyler J. M. et al. reported inhibition of the excretion of MAMP and AMP into the urine by repeated MAMP administration (1). Our experiment using d/l mixture drugs (3) also showed marked inhibition of the excretion of MAMP and AMP into the urine by addition of l-MAMP due to competitive inhibition of d- MAMP metabolism. It is possible that mixture of DMAMP as well as repeated MAMP administration and mixture of l-MAMP in MAMA tablet markedly inhibits MAMP excretion in to the urine. REFERENCES 1. Oyler JM, Cone EJ, Joseph RE, Jr, Moolchan ET, Huestis MA. Duration of detectable methamphetamine and amphetamine excretion in urine after controlled oral administration of methamphetamine to humans. Clin Chem 2002;48:1703-1714. 2. Okazaki T, Nagai T, Amemiya M, Nagai T. Prevalence of d-methamphetamine mixed with l-methamphetamine in JAPAN. Clin Chem Online 2003; 13 Aug 3. Okazaki T, Nagai T, Amemiya M, Matsushima K, Tokudome S, Nagai T. Presumption of racemic ratio in abused MAMP tablet. Clin Chem Online 2003; 7 Aug.