This news item was created by students James Earls, Lesley Oliver, Colleen Beckwith, Jenny Stehly, Kimberly Dark, and Lori Palecek as part of their Chemistry 212 Collaborative Group Activities in WS00 under the guidance of Prof. Rainer Glaser.

Glaser's "Chemistry is in the News"
To Accompany Wade Organic Chemistry 4/e.
Chapter 25. Lipids.


For each of the following questions, please refer to the following article:


DOCTORS SAY FEN-PHEN CAUSES HEART DISEASE
CNN Interactive, December, 1997 (w) contributions from Reuters

Editorial Comments

†††† The group of drugs collectively known as Fen-Phen includes combinations of Ionium, Adipex, Fastin (phentermine), Pondimin (fenfluramine), and Redux (dexfenfluramine).Combinations of these drugs have been known to cause heart valve damage and pulmonary cardiovascular damage.The drugs are all FDA approved separately, however their combination is not. Phentermine (ChemIDplus), an amphetamine-like drug, was first used in the 1960ís as an appetite suppressant. In 1992, the drug gained new notoriety by being paired up with fenfluramine (ChemIDplus), another anti-obesity drug.Together, the drugs cancelled out the tendency of one to act as a stimulant and the other as a depressant.Unfortunately, the drug combination has also caused health problems for many patients.

†††† After it had already been prescribed to millions of Americans, physicians discovered that the drug duo might have been causing heart valve damage in many patients.Heart valve damage, or valvulopathy, occurs when the aortic and mitral valves of the heart do not open and close properly, causing regurgitation of blood back into the heart.Heart valve damage can be detected by an echocardiogram, an ultrasound taken of the heart.Another side effect of Fen-Phen is primary pulmonary hypertension, also known as PPH. PPH is the result of a narrowing of the small and medium pulmonary arteries.

†††† Phentermine has also been found to inhibit the enzyme monoamine oxidase, which helps the body control the amount of serotonin in the blood.Serotonin (ChemID plus) is involved in the transmission of nerve impulses.Fen-Phen was partially designed to enhance serotoninís effects, but in doing so the drug prevented the body from properly regulating the amount of serotonin in its own bloodstream. This lack of regulation results in the production of too much serotonin, a situation that has been linked to heart valve damage.

†††† In 1997, its manufacturer voluntarily withdrew fenfluramine from the market because it was thought to be responsible for health problems in many patients.Since the discovery of the problems, many former Fen-Phen users have filed lawsuits against the manufacturer of the drug(s), as well as the prescribing physicians and diet centers.Many believe that even if the drugs were taken voluntarily, manufacturers and doctors should have a duty to make safe products or to warn patients of possible dangers.


Pertinent Text References
Chapter 19. Amines.

Chapter 23. Carbohydrates & Nucleic Acids.

Chapter 24. Amino Acids, Peptides, & Proteins.

Chapter 25. Lipids.

 

Questions

Question 1: Draw the structures of phentermine and fenfluramine, the two drugs that make Fen-Phen.

 

Question 2: What are the signs and symptoms of valvular heart disease?

 

Question 3: Draw the structure of dexfenfluramine.

 

Question 4: How does fenfluramine alter the way serotonin is metabolized?

 

Question 5: Do you thing that the new drug combination, Xen-Phen, is a wise method of losing weight?

Answers