Does Phentermine cause heart disease?

It has been well documented that lifestyle modifications can assist many in their weight loss journey. Lifestyle interventions include dietary modifications and exercise as a root change. Why are we hesitant to using pharmacotherapies to treat obesity, especially long term? Using Phentermine long term has remained a debated topic despite newer antiobesity medications having the long-term use label. There have been several papers (Hendricks et al) previously reviewed on the efficacy of long term phentermine use specifically, yet a majority has not accepted this. This study further validates the importance of this option. Obesity is a serious and chronic disease and we must treat it as such.

In this study there were three main outcomes evaluated at 6, 12 and then 24 months:

• Heart Rate
• Blood Pressure
• Cardiovascular event or death

Observation of heart rate (HR) showed a slight increase which is to be expected if we understand the drug’s mechanism of action. The magnitude of increase was not significant and cessation of phentermine showed immediate return to baseline. (<.6bpm)

Systolic Blood Pressure (SBP) decreased with weight loss and long term phentermine use. Even in those with hypertension, there was a net-lowering effect in SBP with weight loss and long term phentermine use.

The results showed consistently that there was significantly greater weight loss with phentermine use, even up to 2 years. It is important to note that 30% of the cohort were on phentermine at least one duration >12 months. No observed increase in risk for incident cardiovascular event or death over 3 years of follow up.

Discontinuation of phentermine resulted in weight regain.

Safety and Effectiveness of Longer-Term Phentermine Use: Clinical Outcomes from an Electronic Health

Record Cohort

https://doi.org/10.1002/oby.22430