Methamphetamine characteristics

In terms of the actual substances used, only a tentative breakdown is possible as most countries do not differentiate in detail whether drug users take methamphetamine, amphetamine or other stimulants. However, Member States have repeatedly reported distinct regional characteristics to UNODC, which help establish reasonable orders of magnitude at the regional level. As an example, the information available suggests that amphetamines users in East and South-East Asia consume primarily methamphetamine while users in Europe take primarily amphetamine (with a few exceptions, notably the Czech Republic where methamphetamine is the preferred substance). Household surveys show that about half of the stimulant users in North America use methamphetamine. Captagon use, which is widespread in the Near East, basically reflects the use of amphetamine (often in combination with caffeine). In contrast, users of amphetamines in South Africa and in North Africa, seem to lean more towards methamphetamine. In addition, information available indicates that in most parts of South America, Central America, the Caribbean, in western, central and eastern Africa as well as in some parts of southern Africa and Asia, the amphetamines markets consist primarily of various diverted pharmaceutical preparations. 

Amphetamine and methamphetamine occur as structural isomers and stereoisomers. Structural isomers are compounds with the same empirical formula but a different atomic arrangement, e.g., methamphetamine and phentermine. Stereoisomers differ in the three-dimensional arrangement of the atoms attached to at least one asymmetric carbon and are nonsuperimposable mirror images. Therefore, amphetamine and methamphetamine occur as both d- and L-isomeric forms. The two isomers together form a racemic mixture. The D-amphetamine form has significant stimulant activity, and possesses approximately three to four times the central activity of the L-form. It is also important to note that the d- and L-enantiomers may have not only different pharmacological activity but also varying pharmacokinetic characteristics. 

Cook, C.E., Pyrolytic characteristics, pharmacokinetics, and bioavailability of smoked heroin, cocaine, phencyclidine and methamphetamine, NIDA Research Monograph 99, 6-23. DHHS Pub. No. 1990. 

The consumption of more than one drug over a small window of time and mixing two or more drugs together for a blending of effects is characteristic of club-drug use. As discussed above, ketamine is often mixed with alcohol, GHB, MDMA (ecstasy), rohypnol, and methamphetamine. Some 37% of reported ketamine combination episodes are linked with ecstasy. 

Each drug affects the body in a characteristic way. MDMA and methamphetamine for example, are vasoconstrictors, which decrease blood flow to certain parts of the body. Ketamine is a vasodilator, a drug that increases blood flow. Mixing a vasoconstrictor with a vasodilator (combining ecstasy and ketamine, for example) can dramatically increase blood pressure in the user and boost the risk of sudden cardiac arrest or stroke. 

Molecules such as amphetamine and methamphetamine are different in their amino substitutions on nitrogen and, following the fragmentation pattern seen above, it is clear how these molecules have a common fragment of m/z 119 amu as can be seen in Fig. 6. The other fragment that appears in the CID spectra of these two substances falls at m/z of 91 amu, due to tropylium ion fragment, characteristic... 

Figure 7-2 Fragmentation patterns for the pentafluoropropionyl (A) and carbethoxy-hexafluorobutyryl (B) derivatives of methamphetamine (R = CH3) and amphetamine (R = H masses in parentheses). Compare the predicted masses with the spectrum shown in Figure 7-1. Note that for the pentafluoropropionyl derivative, only one ion (204, 190 m/z) is characteristic of the aliphatic portion of the molecule.

Cook, C.E. Pyrolytic characteristics, pharmacokinetics, and bioavailability of smoked heroin, cocaine, phencyclidine, and methamphetamine. In Miller, M.A., and Kozel, N.J., eds. Methamphetamine Abuse Epidemiologic Issues and Implications. National Institute on Drug Abuse Research Monograph 115. DHHS Pub. No. (ADM) 91-1896. Washington, DC Supt. of Docs., U.S. Govt. Print. Off,... 

Derivatization of the amphetamines is not required for GC-MS analysis. However, because the mass spectra of underivatized amphetamines are very simple and essentially composed of ions at miz 44 for amphetamine and mIz 58 for methamphetamine, derivatization is used to not only yield higher mass ions but also to provide multiple characteristic ions... 

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