Orlistat( Orlistat), better known by the trade name Xenical®, is a weight loss medicine that works by preventing the absorption of fats in the intestine.
Unlike most other drugs used in the treatment of obesity, orlistat is not a suppressor of hunger, it acts only on pancreatic enzymes that digest fat, managing to reduce the absorption of up to 1/3 of the fats consumed in the diet.
In this article we will try to create a bula with language aimed at the lay public, explaining in a simple way how Orlistat acts, how to use it, what are its indications, contraindications, side effects and interactions with other medicines.
WHAT IS XENICAL®
Orlistat is a medicine recommended for people who need to lose weight and can not do it with diet and exercise alone.
Orlistat exerts its anti-obesity effect by inhibiting a pancreatic enzyme called lipase. Lipase is the enzyme responsible for breaking down the fats ingested in smaller molecules, facilitating their absorption by the intestine. Without the action of lipase, the fat that reaches the intestines can not be absorbed, being eliminated practically intact by the feces. Orlistat, therefore, prevents the digestion of fat and, consequently, its absorption by the body.
As its action is restricted to the gastrointestinal tract, and the drug is poorly absorbed by the body, orlistat has a very acceptable adverse effect profile. The main side effects are caused by the great elimination of fat in the stool.
It is important to clarify that orlistat is not able to prevent fat absorption by 100%, an effect that would not really be desired because our body needs this substance to function. In general, orlistat prevents the absorption of 25% to 30% of the fat ingested. This means that without an appropriate diet, which restricts the consumption of fatty foods, orlistat does not have a relevant effect, because if the patient consumes a lot more fats than he needs, even with a 30% reduction in its absorption, alarge amount of fat will still be assimilated.
In addition to assisting in weight loss, orlistat also lowers blood levels of glucose, uric acid and LDL cholesterol, and helps in the treatment of hepatic steatosis and blood pressure control.
Orlistat should be used as a supplemental therapy for weight loss in patients with a body mass index greater than 30 kg / m².
Orlistat increases dietary efficacy by helping the patient to lose an average of 5-10 kg over a 12-month period.
Orlistat is also indicated for patients with BMI over 27 kg / m² who present with other diseases related to overweight, such as type 2 diabetes mellitus( or glucose intolerance), hypertension, dyslipidemia( high cholesterol) or hepatic steatosis.
HOW TO TAKE
Xenical is sold as 120 mg tablets. The indicated dose is 1 tablet 3 times a day, during or shortly after each meal( breakfast, lunch and dinner).Doses greater than 360 mg per day( 3 tablets / day) do not have superior efficacy, therefore, they are not indicated.
Xenical is considered the reference orlistat, but there are already similar medicines in Brazil, containing orlistat in 120 mg tablets. They are: Orlistate, Lystate and Lipiblock.
Alli( not yet available in Brazil and Portugal) is sold in 60 mg capsules or 27 mg chewable tablets. The indicated dose is 1 tablet 3 times a day at each meal( breakfast, lunch and dinner).
Because orlistat interferes with the absorption of fat-soluble vitamins( A, D, E and K), it is suggested that the patient should take a vitamin supplement at night every day before bedtime.
The use of orlistat without an adequate diet, with restriction of fats, compromises the final result of the treatment. Therefore, it is suggested the guidance of a nutritionist on the best diet to be made during the treatment.
Xenical is sold in boxes with 84 tablets, with prices ranging from 180 to 340 reais. There is also the box of 42 tablets, priced between 100 and 200 reais. In Portugal, the box of 84 tablets of Xenical costs about 76 euros.
Similar medications cost a little cheaper.
The most common side effect of orlistat treatment is the presence of fat droplets in the stool. Other symptoms related to non-digestion of fats are: abdominal cramps, increased gas, increased number of daily bowel movements and fecal incontinence. In general, adverse effects are more easily controlled if the patient is disciplined in their diet. The more fats you eat, the more common are undesirable effects.
Headache occurs in up to 30% of patients, back pain in 14%, flu symptoms in 40%, fatigue in 7%, anxiety in 5%, insomnia in 4%, pain to urinate 8% and menstrual irregularity inup to 10% of women.
In the past 10 years, 13 cases of severe liver damage, supposedly associated with the use of the drug, have been described. So far, however, it has not been possible to prove that the complication was directly caused by orlistat. It is worth noting that this drug has already been used by more than 40 million people worldwide without other reports of severe liver damage.
Like any drug, there are cases of allergic reaction, including anaphylaxis, such as the use of Orlistat. These reactions, however, are rare, occurring in less than 1% of cases.
The following drugs may have their absorption altered by the use of orlistat:
- Cyclosporine - an interval of at least 3 hours between administration of orlistat and cyclosporine is required.
- Levothyroxine - an interval of at least 4 hours between administration of orlistat and levothyroxine is required.
- Multivitamins - an interval of at least 2 hours is required between the administration of orlistat and multivitamins.
- Vitamin D analogs - an interval of at least 2 hours is required between the administration of orlistat and the vitamin D analogues( calcitriol, paricalcitol, cholecalciferol. ..).
Patients taking the anticoagulant Warfarin should use orlistat very cautiously as reducing the absorption of vitamin K in the intestines may increase the anticoagulant effect, increasing the risk of bleeding( read: VARFARINA - MAREVAN).
Because orlistat favors the control of glucose levels, in diabetic patients an adjustment in the dose of oral antidiabetics may be necessary in order to avoid episodes of hypoglycaemia.
Orlistat does not interfere with the efficacy of the contraceptive pill( read: CONTRACEPTIVE MEDICINAL INTERACTIONS).
Orlistat is contraindicated in pregnancy and in patients with severe diseases of the liver or biliary tract. Its use during breastfeeding is also not indicated.
In people with intestinal malabsorption syndrome, the use of orlistat may aggravate the condition, so it is contraindicated.