Weight Loss Drug Shows Significant Results in Clinical Trials, but Long-term Effects Remain Unclear
New research indicates the combination of phentermine and topiramate can lead to ample weight loss in some individuals, but questions remain about its effectiveness in older populations and long-term sustainability.
Two recent clinical trials examined the effects of phentermine and topiramate on weight loss. The frist study focused on individuals with type 2 diabetes, while the second included overweight and obese participants, as well as those with type 2 diabetes and other metabolic conditions like high blood pressure.Notably, neither trial included participants over the age of 70, leaving the drug’s impact on older individuals unknown.
Study Results: Dosage Matters
Both studies compared weight loss in participants receiving a placebo, a lower dose of the drug combination, and a higher dose. Results showed a clear correlation between dosage and weight loss, measured as a percentage of baseline body weight after one year.
Study 1 Findings:
* Placebo Group: 2.1% weight loss
* Lower dose (3.75 mg phentermine/23 mg topiramate): 6.7% weight loss
* Higher Dose (15 mg phentermine/92 mg topiramate): 14.4% weight loss
Additionally, a greater percentage of participants in the active treatment groups achieved 5-10% weight loss compared to the placebo group. Specifically:
* 45% of the lower-dose group lost 5% or more of their body weight.
* 67% of the higher-dose group lost 5% or more of their body weight.
* 19% of the lower-dose group lost 10% or more of their body weight.
* 47% of the higher-dose group lost 10% or more of their body weight.
Study 2 Findings:
* Placebo Group: 1.2% weight loss
* Lower Dose (7.5 mg phentermine/46 mg topiramate): 7.8% weight loss
* Higher Dose (15 mg phentermine/92 mg topiramate): 9.8% weight loss
Study 2 demonstrated even higher rates of weight loss in the active treatment groups, likely due to a higher dosage in the lower-dose arm compared to study 1:
* 62% of the lower-dose group lost 5% or more of their body weight.
* 70% of the higher-dose group lost 5% or more of their body weight.
* 37% of the lower-dose group lost 10% or more of their body weight.
* 48% of the higher-dose group lost 10% or more of their body weight.
The placebo groups in both studies saw lower rates of significant weight loss, with 17% and 21% losing at least 5% of their body weight in Study 1 and Study 2, respectively.7% of placebo participants in both studies lost at least 10% of their body weight.
Study Limitations & Sustainable Weight Loss
A significant number of participants – 40% in Study 1 and 31% in Study 2 – dropped out before completion. The data presented did not allow for calculation of average monthly weight loss.
Experts at the Cleveland Clinic recommend aiming for a weight loss of 1 to 2 pounds per week, cautioning against drastic measures due to their unsustainable nature and potential for weight regain. This suggests that while phentermine and topiramate can facilitate rapid weight loss, maintaining that loss long-term requires a sustainable approach.
