• Primary Pulmonary Hypertension
• Pulmonary Hypertension
• Pulmonary Arterial Hypertension
• PPH Symptoms
• PPH Diagnosis
• PPH Causes
• PPH Treatment
  • Ambrisentan
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  • Flolan
  • Remodulin
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  • Thelin
• Diet Drugs and PPH
• Legal Remedies for PPH

Fen Phen and PPH, Dietary Supplements, Primary Pulmonary Hypertension

Fen Phen is a combination drug that was introduced as an anti-obesity or weight suppressant treatment in the 1990's. Fen Phen was recalled from the market by the FDA in 1997 because of data showing that this drug caused heart valve damage and primary pulmonary hypertension. Studies showed that patients who took these appetite suppressants, particularly those whose treatment lasted for more than 3 months, were much more likely to develop primary pulmonary hypertension. The risk of getting PPH increased by 28 times compared to those who had not been treated with Fen Phen.

Fenfluramine, also known as pondimin, was combined with phentermine to create the combination of Fen Phen. (A different formulation of fenfluramine, called dexfenfluramine, was marketed under the name of Redux. This drug was also combined with phentermine to create the combination of Fen Phen.) Although both drugs, fenfluramine and phentermine, had been sold individually for many years, the combination drug was introduced by Home Health Products in the 1990s. (Home Health Products later changed its name to Wyeth Pharmaceuticals.) When the FDA recall occurred, fenfluramine and dexfenfluramine were removed from the market. The detrimental side effects of Fen Phen, including heart valve defects and primary pulmonary hypertension, are attributed to the drugs Pondimin (fenfluramine) and Redux (dexfenfluramine). Phentermine is still sold as an anti-obesity and diet suppressant drug.

How Fen Phen Worked

Fenfluramine was designed to increase the level of neurotransmitter serotonin in the blood. Increased levels of serotonin depress central nervous system activity, which regulates mood and appetite. The end result was a feeling of fullness and loss of appetite. Phentermine also worked on the neurotransmitters in the brain, but instead of being a depressant like fenfluramine, it was a stimulant. It stimulated the "fight or flight" response in the body, which causes the heart rate and blood pressure to increase. This stimulation also reduces or dampens the hunger signal. Phentermine continues to be sold commercially and is similar to other appetite suppressants, such as sibutramine or dextroamphetamine.

It is thought that fenfluramine and dexfenfluramine cause narrowing of the pulmonary arteries and this narrowing is what leads to primary pulmonary hypertension.

Diagnosis of PPH Due to Fen Phen

Although Redux and Pondimin has been removed from the market since 1997, patients are still being diagnosed with primary pulmonary hypertension due to treatment with these drugs. It can take as long as 10 years for the symptoms and effects of PPH to appear after first exposure to Redux or Pondimin treatment. Patients who took these drugs over a longer time period are more likely to develop PPH than those who took the drugs for less than 3 months.

Diagnosis of PPH

If you are being evaluated for PPH symptoms or have been diagnosed with PPH, it is best to inform your physician of any previous use of either Redux or Pondimin.

Last Revision: April 9, 2008

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