Researchers’ attention has turned to find alternatives to the dangerous path of
amphetamines and their derivatives, which unfortunately, still are taken by some
people or even worse still prescribes by unscrupulous doctors. In the case of
orlistat, the idea has been to produce a drug capable of reducing the absorption
of dietary fat, which 98% is made up of triglycerides. This effect has been
achieved through the development of an active substance capable of inhibiting
the gastrointestinal lipase, or those enzymes responsible for splitting the
triglycerides into fragments which are easier to be absorbed by the intestinal
mucosa (fatty acid monoglycerides more).
Thanks to orlistat, triglycerides passes unscathed from the attacks of the
digestive lipases, and are unable to be absorbed by the intestinal mucosa and
are then excreted in the feces. This drug has in fact a chemical structure very
similar to that of the triglycerides. Consequently, the high affinity with the
intestinal and pancreatic lipase, causes the orlistat drug to binds to the
triglycerides in a stable manner, significantly reducing the share available to the
enzymatic digestion of triglycerides.
Effectiveness, side effects and precautions
Studies that have lasted more than two years on the therapeutic effectiveness of
orlistat have shown that in therapeutic doses, its intake leads to weight loss.
There was a weight reduction of 10%, compared to a reduction of 5% in the of
patients that were treated with the same low-calorie diet therapy and placebo. In
the second year of treatment, the subjects switched from placebo to orlistat had
a significant weight loss, while the trend reversed with those patients that went
from orlistat to placebo.
At therapeutic doses (120 mg three times a day, in correspondence with the
main meals), orlistat is able to decrease by 30% the absorption of fat introduced
by an ongoing diet; higher doses do not seem to favor a further loss weight.
The most important issue, are the side effects of orlistat, that lies in the fate of
the triglycerides that escapes the digestive process that metabolized by resident
bacterial flora, causing the classic disorders associated with steatorrhoea. This
condition, which indicates the presence in the feces of a percentage of lipids
higher than normal, is accompanied by flatulence, incontinence, fecal oily
droppings and fecal urgency. These effects are directly proportional to the
quantity of lipid introduced into the meal and thus providing valuable educational
tool. Fearing to run into these problems, the patient tends to become more
aware of the proportion of fat, which introduces the diet, learning to prefer
slimmer food sources.
The orlistat is not recommended in patients with chronic bad absorption,
cholestasis, pregnant and lactating women. Particular caution is advised in the
co-association with hypoglycemic drugs, as orlistat interferes with oral antidiabetic therapy (diabetes type II is very common among obese). Continuous
administration of orlistat is also not recommended with the following drugs:
fibrates, acarbose, biguanides and anorectics.
Treatment with orlistat should be discontinued after 12 weeks if its introduction
does not register a weight loss greater than or equal to 5% of the weight at the
start of therapy. Given its mechanism of action, orlistat is not recommended
when you follow low-calorie eating pattern.