Dear Reader,

[Since this Q&A first appeared, fenfluramine (Pondimin) and dexfenfluramine (Redux) were taken off the market by their manufacturers, at the request of the U.S. Food and Drug Administration (FDA), because of research demonstrating a possible link to heart valve damage from use. As a consequence, the fen-phen drug regimen has not been available since September 15, 1997.]

Alice doesn't know the doctor you spoke with, but she would venture to guess that the reason for the "contrite" answer may have been because s/he simply does not know that much about fen-phen. Unfortunately, not much information exists on the possible health risks of using both drugs in combination for weight loss purposes, or when they are used on a long-term basis. A few studies have been done -- primarily those original trials using both drugs to help obese people (people who weigh 20 to 30 percent over their ideal weight range). The findings from those studies made headlines, but they have also left many unanswered questions. One study lasted four years, and it seems as though many of the participants met with great success. However, about 15 percent dropped out because they couldn't live with the negative side effects. The successful dieters lost, on average, only about 10 percent of their original weight. Several patients who were taking the drugs did not lose weight. And after stopping taking fen-phen, many patients regained weight.

Before going any further, what exactly is "fen-phen," and why has it attracted such attention recently? Both drugs have been around for a while. The US Food and Drug Administration (FDA) approved each drug, fenfluramine and phentermine, individually, for use sometime in the 1960s. Never has the FDA tested both drugs together, nor were either of them approved for use longer than twelve weeks. Only since the early '90s have the drugs been prescribed in combination, and for weight loss purposes. Initially, these drugs were used to treat, among other things, obsessive-compulsive disorders and experimentally to treat cocaine addiction.

Researchers have yet to clearly establish the mechanism by which these drugs act to aid some people in their weight loss efforts. Do they suppress the appetite? Or, do fenfluramine and phentermine effect certain chemicals in the brain in such a way as to diminish food cravings? Some studies have shown that low levels of serotonin (a neurotransmitter) in the brain are associated with feeling o f hunger, and high levels of serotonin with satiety. Fenfluramine, a.k.a. Pondimin, increases serotonin levels -- administering it, in theory, would make a person feel full. It's important to note that the research is mixed. Some studies have found that people who eat a high fat, low complex carbohydrate diet tend to have lower than normal levels of serotonin in their brains. However, eating a diet high in carbohydrates has not been found to increase serotonin levels for a very long time.

Phentermine acts similarly to an amphetamine, e.g. speed, in the way it affects the central nervous system and the metabolism. It too affects brain chemicals -- dopamine and norepinephrine -- and it acts as a stimulant. It's unclear what role "phen" plays in weight loss. In one of the first studies, phentermine was given to patients to counterbalance the depression and fatigue they experienced when taking fenfluramine alone.

Another thing that is not quite clear whether the combination of the two drugs, or long-term use of them poses any serious health risks. We do know the risks, warnings and side effects of the drugs individually. Fenfluramine's most common adverse reactions are drowsiness, diarrhea, and dry mouth. There is the risk of pulmonary hypertension -- probably what you heard about on television. A few cases of pulmonary hypertension have been reported from fen-phen takers. Only one case has been fatal so far. It is not clear what, if any, the prior conditions were. Patients taking fenfluramine with high blood pressure need to be monitored closely. Patients with a history of depression are advised against taking fenfluramine. As for phentermine, although unlikely, the possibility of abuse needs to be kept in mind. Patients with a history of drug addiction should not be prescribed phentermine. Abrupt cessation of taking this drug can result in extreme fatigue and mental depression. Common side effects include insomnia, irritability, hyperactivity, and changes in personality. Maximum dosage for phentermine is 30 mg per day; for fenfluramine dosage must not exceed 120 mg daily although it is usually lower than that initially.

Most of the patients involved in the studies complained of dry mouth, short-term memory loss, dizziness, and diarrhea. Some people do not suffer from any side effects, while others experience those mentioned to varying degrees of severity. Anyone on or considering fen-phen needs to consider a few things first. Do you feel safe exposing yourself to the known and unknown health risks of the long-term use of these drugs? Do the benefits of weight loss outweigh the risks and adverse effects of this drug "therapy?" Do you want to rely on fen-phen for the rest of your life in order to maintain a certain weight, or do you want to try to control your weight on your own? Alice read about one woman on fen-phen who experienced considerable short-term memory loss. For example, the woman reported not being able to remember at which dry cleaners she had left some clothes for almost a year (she never did by the time the article had been printed). But, she felt that she would rather be forgetful than overweight. Each person needs to decide for him- or herself.

Bear in mind, too, that fen-phen was originally intended to help obese patients whose weight poses a health risk in and of itself. Fen-phen is not meant for the person who wants to lose "that last 20 pounds." The fen-phen "diet" needs to accompanied by proper nutrition and an exercise program. A final note, since the recent news shows which covered the fen-phen phenomenon have showed that some of the doctors are over prescribing these drugs, make sure that your doctor goes beyond writing out the prescription. If your doctor doesn't insist and assist you in learning and developing sound nutrition and exercise habits, go find one who will.

Alice

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