Psychostimulants Methamphetamine

Substance-Induced Anxiety Disorder. Numerous medicines and drugs of abuse can produce panic attacks. Panic attacks can be triggered by central nervous system stimulants such as cocaine, methamphetamine, caffeine, over-the-counter herbal stimulants such as ephedra, or any of the medications commonly used to treat narcolepsy and ADHD, including psychostimulants and modafinil. Thyroid supplementation with thyroxine (Synthroid) or triiodothyronine (Cytomel) can rarely produce panic attacks. Abrupt withdrawal from central nervous system depressants such as alcohol, barbiturates, and benzodiazepines can cause panic attacks as well. This can be especially problematic with short-acting benzodiazepines such as alprazolam (Xanax), which is an effective treatment for panic disorder but which has been associated with between dose withdrawal symptoms. 

The popular psychostimulant, me-thylenedioxy-methamphetamine (MDMA, ecstasy ) acutely increases neuronal dopamine and norepinephrine release and causes a delayed and selective degeneration of forebrain 5-HT nerve terminals. 

The best-known products come from the amphetamine group (see Table 1.12) Dexedrine1 1 (generic name d-amphetamine) and Pervitin 1 (methamphetamine) were particularly used in the 1950s and 1960s as stimulants and also as appetite suppressants, but today play hardly any role in medical practice. Ritalin (methylphenidate) has some relevance its psychostimulant action is said to be weaker than that of amphetamines and it is apparent ) less abused than the latter. Because methylphenidate also possesses mild antidepressant activity, in some countries it is used to combat not only narcolepsy and ADHD but also mild depressions without suicide risk (Satel and Nelson, 1989). 

Methamphetamine (MAP) is a psychostimulant that induces enhanced arousal and euphoria acutely, and psychosis and addiction chronically. MAP enters the terminals/neuron via the monoamine transporters (dopamine transporter DAT, serotonin transporter SERT, or norepinephrine transporter NET), displaces... 

Amphetamine and methamphetamine possess an essentially pure psychostimulant effect however, substituted derivatives in position 3 and 4 on benzene ring are defined as entactogene [14], This class of substances includes methylenedioxymethamphetamine (MDMA), methylenedioxyamphetamine (MDA), methylenedioxyethyl-amphetamine (MDEA), and others such as the /V-melhyl-l-(3-4-methylenedioxyphenyl)-2-butanamine (MBDB), methoxymethylenedioxyam-phetamine (MMDA) (Fig. 4). All of these substances are more active in the d form. There are also amphetamine-like substances which combine sympathomimetic (euphoric) and hallucinogen effects they are primary amines, trisubstituted on the benzene ring, that produce effects similar to mescaline. Among these the 2,5-dime-thoxy-4-methylamphetamine (DOM) is the most important. 

Methamphetamine, known on the illicit market as speed, ice, or crystal, is a white crystalline powder, with a bitter taste and odor that dissolves easily in water or alcohol. Similarly to cocaine, it exerts a potent positive reinforcement and it is believed that the dextrorotatory form is responsible for the dopaminergic psychostimulant effect [15]. 

Few studies have examined the effects of delta opioids on abuse-related effects of other psychostimulants. Naltrindole and naltriben, but not BNTX, attenuated both methamphetamine-induced place preferences and the discriminative stimulus effects of low methamphetamine doses in rats however, naltrindole did not alter the discriminative stimulus effects of a higher dose of methamphetamine [140,142], A single dose of 3 mg/kg naltrindole was also reported to block facilitation of electrical brain stimulation by a single dose of methylenedioxymethamphetamine (MDMA) [143]. Finally, a recent study found that both morphine and TAN-67 prevented mecamylamine-induced place aversions in rats chronically-treated with nicotine. These results were interpreted to suggest that both mu and delta agonists may attenuate some aversive effects associated with nicotine withdrawal [144]. 

In conclusion, animal studies have shown that MPH has an abuse liability similar to that of other Schedule II stimulants, including amphetamine, methamphetamine, and cocaine. Actual data on abuse indicate that the pattern of MPH abuse is similar to that of other potent psychostimulants and that MPH is diverted and abused to a similar extent as other pharmaceutical Schedule II substances. Taken collectively, the data indicate that MPH fits the profile of a Schedule II substance. 

Mach et al. (1997) used PET in rhesus monkeys to confirm the similarity of effects among methylphenidate, amphetamine, methamphetamine, and cocaine on dopamine release in the basal ganglia. It is inevitable that methylphenidate will produce similar neurotoxic effects as other psychostimulants. 

The wake-promoting action of psychostimulants as well as the antinarcoleptic compound modafinil was also probed in DAT-KO mice (33). Despite the widespread use of this antinarcoleptic drug in the clinic, the mechanism of its action had not been established. In DAT-KO mice, the wake-promoting action of modafinil, methamphetamine, and the DAT inhibitor GBR12909 was virtually absent. Thus, a role of DAT and DA in the antinarcoleptic action of psychostimulants and modafinil has been postulated (33). 

The psychostimulant activity of selegiline was initially attributed to the two major metabolites of selegiline, L-amphetamine and L-methamphetamine . However, due to their low concentrations in the brain and the low activity of the L-isomers of methamphet-amine and amphetamine compared with the psychoactive D-enantiomers, it seems that their contribution cannot be significant. ... 

Alcohol,psychostimulants (e.g., cocaine and methamphetamine), nicotine, and opiates, increase dopamine levels in the brain. The larger amount of dopamine give rises to feelings of pleasure, and is responsible for craving and drug dependence. 

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