1. Orlistat

Orlistat is a drug that works by preventing the absorption of fats in the intestine, due to the fact that it inhibits gastrointestinal enzymes, this allows reducing the amount of calories that are absorbed at the intestinal level, favouring weight loss and helping to control high cholesterol . 

It is ideal for:  for people who are obese (BMI greater than 30 kg/m2) or overweight (BMI greater than 28 kg/m2) with associated risk factors. It should not be used as the solution to eating more high-fat foods on a daily basis. 

Indication : it is recommended to take 1 capsule of 60-120 mg before, during or up to one hour after each main meal. Skip the dose if one of the meals is missed or does not contain fat.

Side effects: headache, abdominal or rectal pain, bloating, oily stains from the rectum, flatulence, incontinence and faecal urgency, greasy stools, loose or liquid stools, increased defecation, hypoglycemia, fatigue. 

Contraindications: this medicine should not be used by pregnant or lactating women, and in people with intestinal malabsorption problems, cholestasis or who for some reason have a tendency to suffer from diarrhoea. See the drug insert on orlistat . 

Orlistat is available under the trade names Xenical, Redustat, Sagras, Lindeza, Lipogras, Liberat, and Elimens.

2. Liraglutida (Saxenda)

Liraglutide is an injectable medication that acts at the level of the hunger and satiety centre, causing the appetite to decrease. Likewise, one of the effects of the medicine is to change the sense of taste, making food a little less appetising, and it can be purchased in pharmacies under medical prescription.

It is ideal for: people with obesity who have a BMI greater than 30 kg/m² or with a BMI greater than 27 kg/m2 but who have associated diseases, such as high blood pressure or type 2 diabetes. It can also be used to control weight in patients adolescents 12 years of age and older and who are obese. Likewise, these individuals must be accompanied by a doctor and a nutritionist. 

Indication : for both adults and adolescents ≥ 12 years of age, treatment should be started with a low dose, which should be gradually increased during the first five weeks of treatment. The initial dose is 0.6 mg per day, which must be increased weekly in 0.6 mg intervals until the dose of 3 mg once a day is reached in the fifth week. See the package insert for this medicine .

Side effects: the most frequent adverse reactions of this medication are the presence of nausea, vomiting, diarrhoea, constipation, indigestion, gastritis, upset stomach, pain and burning in the stomach, bloating, gas, belching, dry mouth, weakness , tiredness, dizziness and alterations in the sense of taste. 

Contraindications : This drug should not be used by people who are not obese, during pregnancy, breastfeeding, or in children, because the effects of the drug have not yet been determined for this group of individuals.  

Liraglutide is available under the brand name Saxenda or Victoza. 

3. Lorcaserina 

Lorcaserin hydrochloride is an anti-obesity medication that acts on serotonin levels in the brain, decreasing appetite and increasing satiety. By reducing the appetite, less food is eaten, favouring weight loss

It is ideal for: people with obesity, that is, those with a body mass index (BMI) greater than 30 kg/m2 or who are overweight with a BMI greater than 27 kg/m2 and who have some associated comorbidity such as high blood pressure, diabetes or dyslipidemia. However, it can only be used under medical prescription.

Indication : take 2 tablets of 10 mg per day, one at lunch and one at dinner, evaluating the response to the drug after 12 weeks, if the person has not lost 5% of their weight, treatment should be discontinued.

Side Effects:  May cause allergic reactions, increased prolactin, mood swings, vision changes, confusion, priapism (erection lasting more than 4 hours), increased heart rate, sweating, suicidal ideation, tremors, tiredness, or weakness, vomiting, dizziness and low glucose. 

Contraindications:  this medication should not be used by children or adolescents under 18 years of age, during pregnancy and breastfeeding; in people with severe liver and kidney failure, with Peyronie's disease, cavernous fibrosis or who are being treated with drugs for erectile dysfunction. 

Some commercial names with which this medicine can be obtained are: Repentil, Lorcaline, Lorexan, Eudina and Reluctant. 

4. Phentermine (Acxion)

Phentermine is a drug used to treat obesity, because it acts on the central nervous system, suppressing appetite and promoting weight loss

It is ideal for: adults and children over 12 years of age who are obese, that is, a BMI equal to or greater than 30 kg/m2.

Indication : 1 tablet of 15 or 30 mg, 30 to 50 minutes before eating, the last dose must be before 7:00 p.m. Treatment should last a maximum of 12 weeks. 

Side Effects:  Phentermine can cause blurred vision, insomnia, dry mouth, palpitations, rapid heart rate, nervousness, euphoria, and nausea. 

Contraindications:  This medication should be avoided by pregnant women, breastfeeding women and children under 12 years of age. Nor should it be ingested by people with anorexia, who suffer from insomnia, psychotic personality and asthenia; Likewise, it should be avoided by people who take MAOIs (monoamine oxidase inhibitors) to treat depression, because it can cause hypertensive crises. 

The trade name of this drug is Acxion.