Central nervous system anorectic

Compounds available in the United States are Hsted in Table 1. Whereas they vary in degree, all of them share similar HabiUties of cardiovascular side effects, the potential for central nervous system (CNS) stimulation, the development of tolerance, and abuse potential. AH, with the exception of ma2indol, are derivatives of phenethylamine. The introduction of an oxygen atom on the -carbon of the side chain tends to reduce CNS stimulant properties without decreasing the anorectic activity. Following the Federal Controlled Dmg Act of 1970, dmgs were classified into one of five schedules according to medical utiUty and abuse potential. 

The diet pills developed to replace amphetamines became known as anorectics or appetite suppressants and are central nervous system stimulants. The FDA approved phentermine in 1959, fenfluramine in 1973, and dexfenfluramine in 1996. 

Ellinwood, E., Tong, H. (1996). Central nervous system stimulants and anorectic agents. In M. N. G. Dukes (Ed.), Meyler s side effects of drugs An encyclopedia of adverse reactions and interactions (13th ed., pp. 1-30). New York Elsevier. 

The anorectic agents produce adverse effects mainly of the central nervous system sympathomimetic type. Therapy should therefore only be allowed under strict medical supervision, to ensure the earliest possible detection of any signs of drug abuse. Long-term drug treatment of obesity should be avoided altogether. 

Introduction of modified-release formulations has provided some improvement in the use of anorectic drugs. Steady release of the drug permits a constant concentration in the blood throughout the entire day. Thus, a sudden excess of physiological hunger is prevented, and adverse effects involving the central nervous system are diminished. 

Anorectic drugs, which are structurally related to the amphetamines, act mainly on the satiety centre in the hypothalamus and also increase general physical activity (1). All of them, except fenfluramine, stimulate the central nervous system and can cause restlessness, nervousness, irritabihty, and insomnia. Adverse effects also occur through sympathetic stimulation and gastrointestinal irritation. Drug interactions can occur with monoamine oxidase inhibitors. Dexamfetamine, phenmetrazine, and benzfetamine can cause dependence. Some of them have been associated with cardiac valvulopathy and primary pulmonary hypertension (2). 

Mazindol is a tricyclic compound with central nervous system stimulant properties similar to those of amphetamine. It releases and blocks reuptake of dopamine and noradrenaline (1), and the actions of these catecholamines, not serotonin, are responsible for its anorectic activity. With fairly high doses (6 mg/day) central nervous system effects were reported in 30% of 23 patients (2). Euphoria does not occur at therapeutic doses, but can occur at higher doses. It has a much lower addiction potential than the amphetamines and practically no cases have been reported of a physical withdrawal syndrome. 

MR-visible fluorinated compounds that can be measured in the human brain comprise a large number of psychiatric medications including most of the serotonin-specific reuptake inhibitors (SSRIs) such as fluoxetine (Prozac ) [1, 28, 41], as well as pharmaceuticals with mechanisms of action outside the central nervous system such as dexfenfluramine (fen-phen, a serotoninergic anorectic drug) [1, 31]. A recent review [1] covers the impact of MR spectroscopy in psychiatry. 

Amphetamine was the first anorectic drug to be introduced into clinical practice. It was originally synthesised in the 1920 s as a potential substitute for ephedrine and marketed under the trade name of Benzedrine for use as a nasal decongestant. Initially, it was thought to have very little, if any, effect on the central nervous system. However, within a relatively short time it was noted that, in contrast to what had first been thought, amphetamine had pronounced stimulant and mood elevating properties. 

Compounds structurally related to the endogenous sympathomimetic amines epinephrine and norepinephrine have classically been employed as appetite suppressants. These agents, of which amphetamine [300-62-9], C9H13N, is the prototypical example, generally retain the phenethylamine, but lack the catechol moiety present in the natural substances. As a consequence, they are well absorbed after oral administration and readily distribute into the central nervous system where they exert their anorectic effects at hypothalamic appetite control centers. A component of their efficacy in promoting weight... 

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