The latest anti-obesity drug “Mysimba” and patient safety
An article published in the British Medical Journal(1) discusses the decision of the European authorities regarding the approval of the new anti-obesity drug “Mysimba”, marketed under the name “Converge” in the USA.
However, according to Prescrire magazine, the latter representing a real indication in obesity, has a mechanism of action comparable to some banned active ingredients, which raises a key question about the future use of this new anti-obesity drug as well as the safety of patients recently treated with Mysimba.
A mechanism of action to reduce appetite and known adverse effects
Mysimba includes a combination of two well-known active ingredients, naltrexone, mainly used in the treatment of alcoholism or addiction to tobacco and other opioids, and bupropion, which is an extended-release antidepressant. The mechanism of action of Mysimba, explains the manufacturer Orexigen Therapeutics, is mainly targeted at the central nervous system or CNS, involving in particular the hypothalamus and thedopaminergic reward system, tocontrol the pleasure related to eating.
Associated with regular physical exercise, this new anti-obesity drug would allow in 45% of patients, a weight loss that can equal 5% of body weight, which is not negligible. However, it is important to remember that Mysimba hasknown side effects, and that it must therefore be prescribed by a doctor, who will monitor and supervise the intake and effects of the treatment, and will also evaluate the benefit-risk factors related to each patient individually.
Mysimba approved by the European Authorities
To confirm this approval decision, the European Authorities rely on data from several clinical trials, carried out on more than 4500 participants, including overweight or diagnosed obesity. The results show a significant weight loss, for participants who underwent Mysimba treatment, equalto 9.3% of body weight. For the different groups who consumed a placebo, the results are between 1.3% and 5.1%, depending on the studies.
In addition, the adverse reactions reported during these clinical trials are mainly mild, with for the most frequent, nausea, headache, constipation, vomiting, dizziness, and dry mouth. Tests have been carried out regarding possible cardiovascular safety, demonstrating that Mysimba would not significantly increase this risk.
However, there is still some uncertainty about cardiovascular risks in the long term, despite the studies carried out. To definitively rule out cardiovascular safety, a study is already planned, and will soon be carried out.
The European authorities also take into account in their decision the severe increase in obesity, which has become a real public health problem (see the latest ObEpi-Roche statistics & surveys on this subject).
To conclude, obesity remains an urgent problem to be solved, and the European Authorities stress the importance of pharmacological support, associated with regular physical activityand a change in diet. The France will remain very closely monitored, having already been confronted with a pharmacovigilance problem, particularly with regard to the “Mediator”.
Stephen Paul is the lead author and founder of My Health Sponsor. Holder of a diploma in health and well-being coaching with more than 200 articles in the field of health, he makes it a point of honor to offer advice based on reliable information, based on scientific research, and verified by health professionals.