Diet Doctors Watching Fen-Phen
Last week’s Mayo Clinic announcement describing heart valve problems in women taking the popular diet drug combination of fenfluramine and phentermine has sparked a variety of reactions from weight-loss doctors nationwide.
Some will no longer offer the “fen-phen” regimen. Effective immediately, physicians at Jenny Craig’s weight-management programs have been instructed to no longer write fen-phen prescriptions, says Brian Luscomb, a spokesman for the La Jolla-based company. Until recently, about 500 of the company’s 793 centers offered the fen-phen option.
But other weight-loss center operators are taking a wait-and-see stance. “We’re waiting until our medical board evaluates the Mayo Clinic data,” says Joseph DiBartolomeo, vice president of scientific affairs for Nutri / System and its affiliate, U.S. Medical Weight Loss Clinics, which together operate more than 500 weight-loss clinics nationwide. “We’re giving every patient the option of coming in to see their physician and discuss it.”
The Mayo Clinic report is called “junk science” in a letter sent out to patients last week by Dr. Don S. Jensen, president and medical director of Manhattan Medical Weight Control, which operates 17 centers in Southern California and one in Fresno. “The latest report out of the Mayo Clinic has many holes in it,” he writes.
Like many weight-loss physicians, Jensen plans to continue prescribing the regimen and to keep closer tabs on any potential cardiac side effects. “We will listen to the patient’s heart, as we have done before,” Jensen says, “but now we will do so more frequently, at least every eight weeks.”
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Paying even closer attention to potential cardiac problems is also the plan for patients at the UCLA University Obesity Center, says Dr. Morton Maxwell, co-director. He also hopes to perform random echocardiograms, ultrasound examinations of the heart.
The Mayo Clinic report, detailing valve problems in 24 women mainly from Minnesota and North Dakota on fen-phen, is due to be published in August in the New England Journal of Medicine. But the usual pre-publication embargo was lifted, allowing the researchers to discuss the findings early because of public health implications.
The women had no known history of heart problems; five have undergone surgery to repair the problems. In the wake of the Mayo report, the Food and Drug Administration has issued a public health advisory, alerting “many thousands” of doctors about the finding. As of July 8, the FDA has received reports of 33 cases of valve abnormalities in women on fen-phen. Last year, 18 million monthly prescriptions were written in the U.S. for fen-phen, according to the Mayo researchers.
In a telephone interview, Dr. Jack Crary, an interventional cardiologist at MeritCare Medical Center in Fargo, N.D., where 19 of the 24 patients were found, traced the history of the findings.
“We first saw a patient with valvular heart disease in December 1994,” he says. By January 1997, more had shown up, and Crary called the Mayo Clinic in Rochester, Minn., curious if they had found similar patients. Dr. Heidi Connolly, a Mayo cardiologist and lead author of the paper in the journal, had.
While other physicians say the findings may not bear out in other populations, or that other factors may be to blame, Crary says: “We strongly suspect these medications cause valvular heart disease. Something is happening to the valves. They thicken and don’t close properly and leak.”
Exactly how the medicines may cause the heart valve problems isn’t known, but one speculation is that higher circulating levels of the hormone serotonin, due to fenfluramine use, may act as an irritant on the valve surfaces. Some heart valve problems may be diagnosed long after patients discontinued the fen-phen regimen, Crary says, and their new doctors may not even think to ask about diet pill use.
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The Mayo Clinic findings of valve problems have not shown up here, say several local weight-loss experts.
Since 1993, more than 1,000 people enrolled in the UCLA program have taken fen-phen, Maxwell says, and there are no known reports of valve problems.
Likewise at Manhattan Medical, says Jensen, who estimates that 50,000 patients have been on the regimen at his centers since 1992.
Both fenfluramine and phentermine are FDA-approved for weight control, but the combination is not approved. The combination became popular after a University of Rochester study found the two pills together effective for weight loss in the obese. Soon, doctors began prescribing the combination, a practice commonly accepted and known as “off-label use.”
Patients on fen-phen should discuss the Mayo findings with their doctors, the Mayo researchers advised.
Symptoms of heart valve problems can include shortness of breath, fatigue and swollen ankles, Crary says. But “some don’t have symptoms at all.”
And if patients decide to abandon fen-phen?
Discontinue the medicine gradually, tapering off over about two weeks’ time, Maxwell advises. “Ideally, cut the dose by a half for a week or so, then by a quarter for a week,” he says.
Depression has been reported after abrupt cessation of fen-phen, Maxwell says, but “we’ve had hundreds of people stop abruptly and there have been no adverse effects.”
And what about patients who decide to continue on the fen-phen regimen?
They can take a number of steps to minimize problems, Maxwell says. Go on the lowest effective dose. At the UCLA program, an average dose is 30 milligrams of fenfluramine and 15 milligrams of phentermine daily. Starting doses are even lower--20 milligrams of fenfluramine and 8 milligrams of phentermine.
In the Mayo report, women took 20 to 220 milligrams of fenfluramine and 15 to 60 milligrams of phenermine daily. Consider the drugs, meant only for the obese, only one part of a weight-control program, Maxwell adds. Other integral components: behavior modification, caloric restriction and exercise.
