Control of methamphetamine misuse
Authors: Tracy D Gunter
Journal: BMJ (2007)

Methamphetamine is a highly addictive substance that has caused serious public health problems globally.1 As it is relatively easy to manufacture from precursor substances, regulation of precursors has taken centre stage in global strategies for drug control. Recently, the UK Medicines and Healthcare Products Regulatory Agency announced that the precursors pseudoephedrine and ephedrine, also used in flu remedies sold over the counter, may in future be available on prescription only.2

Methamphetamine was first synthesised in Japan in 1919 and has been manufactured legally in the United States since the 1950s. Use declined during the 1970s when the public became aware of the harms of amphetamines and practitioners were inhibited from prescribing them by the Controlled Substance Act (1970) www.answers.com/topic/single-convention-on-narcotic-drugs. However, when methamphetamine re-emerged in the 1980s, it had been transformed into “ice,” a smoked form of high purity that produces sustained intoxication. As it exists today, illicit methamphetamine is manufactured in many forms and may be used in many ways (inhaled, ingested, smoked, or injected).

Many definitions of which substances are included in the class of synthetic stimulants or amphetamine-type substances exist,3 but generally the class includes amphetamine, methamphetamine, and 3,4 methylenedioxymethamphetamine (MDMA or ecstasy). They cause increased energy, decreased appetite, and a heightened sense of wellbeing. The onset and duration of action vary by specific compound, dose, purity, and route of administration. Complications of use vary greatly and include cardiovascular, neurological, and psychiatric effects. Other possible complications include risk taking behaviour during intoxication and heavy metal exposure as a result of mercuric chloride and lead acetate used in the illicit production of methamphetamine.4 5

According to the World Drug Report issued in 2006 by the United Nations Office of Drugs and Crime,6 around 200 million people used illicit drugs. Amphetamine-type substances ranked second, after cannabis, with an estimated 35 million users. Of these, 25 million used amphetamines (including methamphetamine) while the remaining 10 million used ecstasy. When all indicators of amphetamine production and use were combined, the overall global trend was towards a stable to mildly increasing amphetamine market after years of annual increases. However, the results of specific market indicators were mixed, and trends for specific geographical regions varied.

The report also found that seizures of substances diverted for manufacturing amphetamine-type substances reached record levels and exceeded seizures of the end product in 2005.6 The main methamphetamine precursors seized were pseudoephedrine and ephedrine. The main amphetamine precursors seized were phenyl-2-propanone and phenylacetic acid.6 Although the rate of dismantling laboratories that produce amphetamines has increased, dismantling of large volume international laboratories (so called superlabs) has not.

The relation between the regulation of precursor substances and outcomes in drug users, such as hospital admissions and arrests, has been reported by two studies in the US.7 8 They concluded that regulations limiting access to bulk powder and single ingredient ephedrine and pseudoephedrine products reduced hospital admissions and arrests. However, regulations targeting mixed agent cold remedies used by small scale manufacturers did not result in similar decreases. 

So what is the most effective strategy to reduce harm from amphetamine-type substances? Although the manufacture and misuse of synthetic stimulants contribute greatly to morbidity and mortality in substance users worldwide, the global disease burden of this class of substances is much lower than that of tobacco, alcohol, and marijuana.6 9 10 Also, most people who use amphetamine-type substances take multiple substances.11

Even if the pattern of drug use is stable over time, drug markets are dynamic. Efforts to prevent the manufacture and use of amphetamine-type substances should, therefore, be integrated into a rational scheme to reduce overall substance use that is designed to tackle existing and emerging drug threats. Overinvesting resources in the control of one drug, or one precursor, carries with it the risk of failing to appreciate emerging threats. For instance, many people fear the “meth crisis,” but fewer seem aware of the recent warnings issued by the UN Office of Drugs and Crime about the resurgence of cocaine in Western Europe.12

Responses to this crisis should include limiting supply and distribution,13 educating the public about harms, screening for early use, and aggressively treating addiction in an integrated approach that tackles addiction in its many forms.