Obesity is a highly prevalent condition in the United States that is correlated with shortened life expectancy, high blood pressure, cancer, diabetes, and cardiovascular disease. A recent 2011 study on reducing obesity has given new hope to people struggling with the condition and its related disorders. By combining Phentermine and Topiramate, two pre-approved obesity drugs, researchers have increased weight loss efficacy while decreasing harmful side effects.
Phentermine is a drug that has been previously used as an appetite suppressor. It works by releasing norepinephrine (adrenaline) into the body where it elicits a flight or fight response, halting appetite and increasing the breakdown of fat molecules into energy. In addition, phentermine leads to the (slight) increase of serotonin and dopamine which are neurotransmitters important in regulating mood and well-being. This drug in combination with Topiramate, an established anticonvulsant, was hypothesized to have weight reduction properties. Topiramate has been used in the past, by itself, for weight reduction but required high doses which prompted excessively negative side effects such as depression.
The efficacy of the combination drug therapy (Phentermine + Topiramate) was studied using about 2500 patients. Patients were selected by body mass index and the presence of comorbidities such as diabetes, hypertension, and abdominal obesity. Afterwards, 1000 participants were given a placebo (group 1), 500 participants were administered a half dose of the drug combination (group 2), and 1000 patients received a full dose of 15 mg Phentermine with 92 mg Topiramate (group 3). This therapy was combined with a light exercise and diet program for the course of one year.
The results show that the drug combination is therapeutically effective for weight loss. Further, looking into individual patients’ comorbidies showed decreases in waist girth, blood pressure and inflammatory factors, as well as stabilized glucose levels. However, it is important to consider that the effectiveness of any drug is based on the comparison of its therapeutic value to negative side effects. In the third group, which received a full dosage of the drug combination, 21% reported symptoms of dry mouth and paraesthesia, 17% reported symptoms of constipation, 10% reported symptoms related to insomnia, and 7% and 8% reported feelings of depression and anxiety, respectively.
This therapy has now completed a stage three clinical trial and will be sent to the FDA for approval. If approved, it will be available for prescription within the next 2.5 years.
