Ice is recrystalised methamphetamine hydrochloride. Methamphetamine is a potent and very addictive stimulant first synthesized in Japan in 1919, and is being abused at an increasing prevalence (in a 1996 survey, nearly five million Americans had used this drug at some time in their lives—up from approximately 3.8 million in 1994.)(1).

Ice is an indirectly acting sympathomimetic that causes a massive release of dopamine in the brain. The marked increase in dopamine levels may be related to the subjective 'high', similar to that observed with cocaine administration, and some of the neurologic complications are likely due to dopamine-mediated vasoconstrictive effects (2). Thus this drug induces in users experiences of euphoria, increased alertness and confidence, and reduced fatigue and appetite by blocking the reuptake, and stimulating the dopamine and norepinephrine releasing in the central nervous system. While methamphetamine may be smoked, taken orally, or injected intravenously, Ice -the "drug of power-" can only be smoked.

In contrast to base cocaine, acute effects of smoked meth may last between 4 and 24 hours as it has a plasma half-life of 12 hours. Smoked in a base form, it is usually known as SNOT, this term being related with its similarity to the natural product of the same name (3).

Among withdrawal symptoms it has been reported severe craving, depression, fatigue, inertia, paranoia, and maniac-depressive psychosis. Medical complications associated with Ice abuse include severe neurologic and psychiatric conditions, such as haemorrhagic and ischemic infarcts, subarachnoid haemorrhages, memory loss, and psychosis(4).

Clinical and preclinical observations suggest that methamphetamine may cause long-lasting injury to the brain. In humans, some of the psychiatric disorders, such as paranoid psychosis, may occur not only acutely during methamphetamine exposure but may persist for months or even years after cessation of abuse. Its neurotoxic effects has been observed in rhesus monkeys for as long as 4 years after the last drug exposure. Furthermore, several studies in rodents have shown that methamphetamine is toxic to dopaminergic and serotonergic neurons. However, in humans, only two recent PET studies demonstrated decreased dopamine transporters, which suggests long-lasting neurotoxicity due to methamphetamine abuse (5).

Smokable methamphetamine is like the crack. They may both briefly be delightful but offer only a toxic and delusive short-cut to the biological nirvana awaiting our descendants (3).

1. Office of Applied Studies. Preliminary results from the 1996 National Household Survey on Drug Abuse. : Substance Abuse and Mental Health Services Administration, 1996.
2. Wang AM, Soujanen JN, Colucci VM, Rumbaugh CL, Hollenberg NK. Cocaine- and methamphetamine-induced acute cerebral vasospasm: an angiographic study in rabbits. AJNR Am J Neuroradiol 1990; 11:1141–1146.
3. Ice.
4. Smith DE, Fischer CM. Acute amphetamine toxicity. J Psychedel Drugs 1969; 2:49–54.
5. Volkow N, Chang L, Wang G, et al. Evidence in humans that methamphetamine abuse produces long lasting changes in dopamine transporters. Presented at the Society of Nuclear Medicine Meeting. Los Angeles, CA. 1999.