“Treatment of obesity and related pathologies threatens the collapse of public health systems”
Mujaro (tirzepatide) is the latest drug added to the pharmacological arsenal against obesity. This drug, also indicated for type 2 diabetes, has been shown to reduce weight by up to 23 kilograms. But, like its predecessors, it is expensive, can have side effects and is not indicated in all cases. For all these reasons, endocrinologist Aurelio Martis Sueiro of the Concho Provincial Hospital warns of the need to remain vigilant and seeks to promote healthy habits in all areas, from families to companies, because, he warns, the availability of these drugs should not be the solution, or at least not the only solution, to combat obesity, a metabolic disorder that affects almost 20% of the Spanish population.
– Why is obesity a public health problem?
– Obesity is a major public health problem in most countries, both developed and developing, because, in addition to being very common, it is the cause or precedent of many associated diseases, such as type 2 diabetes, hypertension, lipid metabolism disorders, sleep apnea, fatty liver, degenerative joint diseases or various types of cancer. The treatment of obesity and related pathologies threatens the collapse of public health systems.
– How many anti-obesity drugs are available in Spain today?
– We have different drugs for obesity. Some of them have been used in everyday clinical practice for many years, such as orlistat (Alli or Xenical); the combination of naltrexone-bupropion (Misimba), both for oral use, and liraglutide (Saxenda), which must be administered daily. Recently, semaglutide (Vegovi) and tirzepatide (Munjaro), which must be administered once a week, have been introduced into the pharmacopoeia. In clinical practice, we currently prescribe only the last two drugs.
– How do they work?
– Orlistat reduces intestinal fat absorption, resulting in weight loss that depends on the percentage of fat consumed. It has been shown to improve metabolic control in patients with diabetes or to reduce the manifestations of diabetes in susceptible groups, as well as in high blood pressure and dyslipidemia. The resulting weight loss is insignificant. The combination of naltrexone and bupropion suppresses the hunger center. Moderate weight loss is achieved, and the percentage of those who dropped out of clinical trials is very high. Liraglutide, administered daily, suppresses appetite and slows gastric emptying. Moderate weight loss is achieved, manifestations of diabetes, high blood pressure and dyslipidemia are reduced. Semaglutide, like liraglutide, works by stimulating receptors for the gut hormone GLP-1, which slows gastric emptying and, by acting directly on the brain, increases feelings of satiety, but it is more potent than liraglutide and is given once a day for a week, so weight loss is greater.
– And Tirzepatide, the latest drug approved in Spain?
– Tirzepatide stimulates both GLP-1 receptors, thereby increasing insulin secretion, inhibiting gastric emptying and enhancing satiety, but it also acts through another gut hormone, GIP, which has receptors in adipose tissue, stimulating energy expenditure. Tirzepatide is also administered once weekly.
– What does it add to the existing arsenal?
– Tirzepatide has a dual action: it stimulates both GLP-1 and GIP receptors. GIP has less effect on gastric emptying than GLP-1, but unlike GLP-1, there are GIP receptors in adipose tissue, which increases energy expenditure and weight loss.
– What do these drugs mean in the fight against obesity?
– The data obtained during clinical trials of the two latest drugs are very encouraging and open the door to the fight against this pathology, the prevalence of which has only increased in recent decades.
– Will they leave obesity in the past in the future?
– Now we must be careful and wait to see the results in real life in the short term, but above all in the long term.
– Could this therapeutic arsenal be counterproductive? Could it make us not watch our diet, given the possibility of fighting excess weight with drugs?
– Without a doubt. We must not make the mistake of thinking that the problem has already been solved. There are obese people for whom the drugs will not be effective, there will probably be people for whom the drugs will lose their effectiveness over time, and there will be many people who simply cannot afford them.
– So, what message would you send to the population?
– That we should not let down our guard at this time. In my opinion, the greatest effort we as a society should put into obesity prevention. Families, schools, food companies, government bodies… should promote healthy eating and healthy lifestyles.
– These are expensive drugs that are not included in the social security portfolio, which means that many patients cannot access them. Should they be?
– This is the most common opinion among medical workers. There should not be different treatment for some patients and others depending on the type of pathology they suffer from.
– For whom are they indicated and for whom are they not?
– Anti-obesity drugs are indicated for adults with a body mass index (BMI = weight in kilograms divided by the square of height in meters) greater than 30 or greater than 27 with concomitant diseases.
– Is there a drug indicated for pediatric patients?
– Both liraglutide and semaglutide can be used in children aged 12 years and older. The remaining drugs are not yet indicated in pediatrics. It is known that the use of tirzepatide in patients under 18 years of age is being studied, but at the moment its use is not recommended.
– Is treatment enough or do you also need to monitor your diet and exercise?
– A healthy, low-calorie diet and exercise, both aerobic such as walking, cycling, swimming, and strength training such as using weights or resistance bands, are things we never stop recommending when we are going to prescribe any kind of therapy to people with obesity, including medications.
– What kind of weight loss do these drugs achieve?
– Weight loss with orlistat and naltrexone-bupropion is moderate and usually not sustained over time, with liraglutide weight loss of 5 to 10% of body weight has been reported, with semaglutide weight loss can average about 15%, and with tirzepatide it can exceed 20% at high doses.
– Do they also reduce comorbidities?
– Weight loss by itself, by any method, already reduces the manifestation or, if present, improves the development of pathologies associated with obesity. But, first of all, the newest drugs that have appeared for the treatment of obesity improve both type 2 diabetes (we must not forget that these drugs were initially developed for the treatment of diabetes), and hypertension, dyslipidemia, respiratory problems, fatty liver, heart disease and kidney disease.
– Main side effects.
– Orlistat may cause abdominal cramps and fecal incontinence, kidney stones and decreased absorption of some vitamins. The combination of naltrexone and bupropion may cause increased blood pressure and heart rate, headaches, nausea, constipation and cramps. Liraglutide may cause nausea and vomiting, gallstones and very rarely pancreatitis. Semaglutide may also cause side effects such as nausea, vomiting, diarrhea, constipation and very rarely pancreatitis. The most common adverse events with tirzepatide are nausea, vomiting, diarrhea and isolated cases of pancreatitis.