The possible link between phentermine and heart failure is due to rare reports of valvular heart disease in people who took the medication. The medication can also cause pulmonary hypertension, which can be fatal. Physical and psychological dependence can occur with long-term use of phentermine. After prolonged use, a withdrawal reaction may occur, including excessive sleepiness, fatigue, tremors, and depression.
The study found that patients who took long-term phentermine and who stopped taking phentermine abruptly because of their choice did not have an amphetamine-like withdrawal symptom complex. Fear of the adverse effects of phentermine does not inhibit the use of phentermine by specialists in the treatment of obesity. In this prospective study, the addictive potential of phentermine will be evaluated with validated psychometric scales to examine patients who have been taking phentermine long-term for two years or more. These expectations were based on the structural chemical similarities between phentermine and amphetamine and on the evidence in rats that phentermine stimulated spontaneous activity.
A recent retrospective study investigated the symptoms that occur when patients treated with long-term phentermine in a weight management program abruptly stopped taking phentermine. Although phentermine is the agent of choice among physicians specializing in the treatment of obesity, the use of this medication by other doctors for the treatment of obesity has long been reduced due to misunderstandings about the safety of phentermine. Participating patients who have taken long-term phentermine in this study will be asked to discontinue phentermine treatment for 48 hours to participate in the study.