Drug treatments of obesity

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OBESITY AND CORONARY HEART DISEASE 369
psychological characteristics, such as preoccupation with food and depression, than the
surgery group (Halmi et al. 1980). Thus, permanent weight loss through surgery
brought both physical and psychological benefits. Weight loss, therefore, can be beneficial in the obese, but only if treatment is successful and the results are permanent.
Therefore, dieting may be rejected as a treatment but weight loss may still be seen as
beneficial.
An argument for treating severe obesity can be made, but only if a positive outcome
can be guaranteed, as failed treatment may be more detrimental than no treatment
attempts at all.
The treatment alternatives
The problems with dieting
The implications of restraint theory suggest that the obese should avoid restrained
eating. Dieting offers a small chance of weight loss and a high chance of both negative
physical and psychological consequences. Taking dieting out of the treatment equation
leaves us primarily with drug treatment and surgery.
Drug treatments of obesity
Drug therapy is only legally available to patients in the UK with a BMI of 30 or more and
government bodies have become increasingly restrictive on the use of anti-obesity drugs.
For example, both fenfluramine and dexfenfluramine were recently withdrawn from
the market because of their association with heart disease even though they were both
quite effective at bringing about weight loss. There are currently two groups of antiobesity drugs available which are offered in conjunction with dietary and exercise programmes. The first group act on the gastrointestinal system and the more successful of
these reduce fat absorption. Orlistat is one of these and has been shown to cause substantial weight loss in obese subjects (James et al. 1997; Sjostrom et al. 1998; Rossner et
al. 2000). It can be, however, accompanied by a range of unpleasant side effects including liquid stools, an urgency to go to the toilet and anal leakage which are particularly
apparent following a high fat meal. Although Orlistat is designed to work by reducing
fat absorption it probably also has a deterrent effect as eating fat causes unpleasant
consequences. The second group of drugs work on the central nervous system and
suppress appetite. The most commonly used of these are phentermine which acts on the
catecholamine pathway and sibutramine which acts on the noradronergic and serotonergic pathways. There is some evidence for the effectiveness of these drugs although they
can also be accompanied by side effects such as nausea, dry mouth and constipation
(Lean 1997). Current recommendations state that drugs should be used only when other
approaches have failed, that they should not be prescribed for longer than three months
in the first instance and should be stopped if a 10 per cent reduction in weight has not
been achieved (Kopelman 1999).
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