Fenfluramine/phentermine

Fenfluramine/phentermine (also known as Fen-Phen) is a combination of two drugs, fenfluramine and phentermine, that was widely prescribed for weight loss in the 1990s.

History

Fenfluramine and phentermine were both approved by the Food and Drug Administration (FDA) as individual weight loss drugs in the 1970s. In the 1990s, doctors began prescribing them together for patients who had not had success with diet and exercise alone. This combination became known as Fen-Phen.

Pharmacology

Fenfluramine works by increasing the level of serotonin in the brain, which helps to control appetite. Phentermine is a stimulant that suppresses the appetite by affecting the central nervous system.

Side Effects and Controversy

In 1997, the FDA requested the withdrawal of fenfluramine and its derivative dexfenfluramine from the market after the drugs were associated with heart valve disease and pulmonary hypertension. The use of Fen-Phen has been linked to serious medical complications, including primary pulmonary hypertension (PPH) and heart valve disease.

Legal Issues

Following the FDA's announcement, numerous lawsuits were filed against the manufacturers of fenfluramine, including a class-action lawsuit in 1999. The manufacturers agreed to a $3.75 billion settlement in 2000.

Current Status

As of 2020, fenfluramine is no longer available in the U.S. Phentermine is still prescribed for short-term weight loss, usually for a period of a few weeks.

Fenfluramine/phentermine

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  Fenfluramine and phentermine chemical structure
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  3D model of Fen-Phen