According to a study published in the Journal of the American Medical Association, newer anti-obesity drugs such as Lorcaserin and Phentermine have helped patients drop between 3-9% of their body weight. Each drug however does come with some precautions such as oily stool, possible birth defects or gastrointestinal lipases.
The study’s researchers report that Orlistat with 3% weight loss and 10% with Phentermine after 1 year. The researchers Susan Yanovski, MD and Jack Yanovski, MD, PhD of the National Institutes of Health reviewed studies on approved obesity drugs in the United States. All trials were randomized and fully controlled and had to run for at least one year’s time. They also had to include data on at least 50 patients per group with 50% retention. Also all of the results needed to be reported on an intention-to-treat basis.
They found a large range of mean percentage of body weight lost with patients depending on the drug being studied. The drug Qnexa showed the most weight loss for patients. It’s important to note that this weight loss occurred as a result of a proper diet and regular exercise while taking this obesity medication.
Overall, the study’s researchers looked at 21 different studies – 4 on Lorcaserin, 2 on Qnexa and 15 on Orlistat. They found that the proportion of patients who achieved a clinical weight loss (at least 5% of body weight) was anywhere from 35-73% for Orlistat users, 37-47% for Belviq and 67-70% for Qnexa.
It’s no secret that these drugs come with cautions. Orlistat has the worst with the risk of gastrointestinal lipases that can lead to excretion of 30% of ingested fats or oily stool. According to Timothy Garvey, MD, the drug trains the diet and users cannot eat fats. If they do, they deal with those gastrointestinal side effects.
Topiramate has a potential for future birth defects for users. The neurological agent can increase the risk of oral clefts in babies born to mothers who became pregnant while taking the obesity medication. Some patients also experience a small increase in heart rate while using the drugs, which also has raised concerns for physicians.
Also, Belviq has similarities to fenfluramine, which is a harmful part of Fen-Phen which was tied to problems with the heart valve. This new drugs targets the 5HT2C receptor, not found in heart muscle, which was the target of fenfluramine.
Despite these risks, all three obesity drugs produced greater cardiometabolic risk factors improvements compared to the placebo drugs. According to the researchers, no obesity medication has shown any ability to reduce cardiovascular morbidity or mortality in any way.
The study’s researchers, the Yanovskis, also evaluated any noradrenergic medications, which have been known to have limited information on long-term safety since their developments. These drugs include Benzphetamine, Diethylpropion and Phendimetrazine. The latter is the most widely-prescribed drug in the United States with nearly 25.3 million prescriptions for 6.2 million users from 2008 to 2011 alone.
Although these are few indicators of who will respond well to certain medications, the study’s researchers believe that these obesity drugs do increase the chance of successful weight loss when combined with proper diet and regular exercise.