Former Fen-Phen users may need prophylactic antibiotic before treatment

July 1, 1998
The use of non-amphetamine appetite suppressants has in-creased during the last decade. In the late 1980s, Phentermine (Ionamin) had been prescribed to patients for weight loss. The drug by itself proved to have a wide safety margin. In 1996, a new appetite-suppressant drug was combined with Phentermine for greater success. Fenfluramine (Pondimin) was combined with Phentermine so that lower dosages of each drug could be taken with a greater efficacy than taking each drug alone at higher doses. T

Cynthia R. Biron, RDH

The use of non-amphetamine appetite suppressants has in-creased during the last decade. In the late 1980s, Phentermine (Ionamin) had been prescribed to patients for weight loss. The drug by itself proved to have a wide safety margin. In 1996, a new appetite-suppressant drug was combined with Phentermine for greater success. Fenfluramine (Pondimin) was combined with Phentermine so that lower dosages of each drug could be taken with a greater efficacy than taking each drug alone at higher doses. The combination became known as Fen-Phen.

A sustained-release Fenfluramine called Dexfenfluramine (Redux) was manufactured and used in combination with Phentermine for the ultimate Fen-Phen combination. This combination was approved by the Food and Drug Administration (FDA) in 1996 after three years of clinical trials. The trials demonstrated long-term efficacy and safety when the combination of drugs was used on 1,388 patients ages 18 to 60.

Since the drugs Pondimin and Redux became available, 18 million prescriptions of the Fen-Phen combinations have been written. In a study conducted at the Mayo Clinic in Rochester, Minn., 24 women ages 44+/-8 years were evaluated 12.3+/-7.1 months after initiation of Fen-Phen treatment. The women had signs and symptoms of heart disease. All 24 women had no previous history of cardiac disease prior to Fen-Phen therapy. Echocardiograms revealed unusual valvular morphology and regurgitation in either/or right and left sides of the heart in all 24 women. Eight of the women also had been diagnosed with pulmonary hypertension. Five of them required cardiac surgery.

Histological examinations of valve tissues showed plaque encasement of leaflets and changes in their anatomical structure. These cases and several others raised concerns of Fen-Phen-associated valvular heart disease. It was this study and additional reports that prompted the FDA to take Redux and Pondimin off the market in September 1997.

Phentermine (Ionamin) was not taken off the market. The FDA is requesting that all health-care professionals report any cases of valvular heart disease associated with Redux or Pondimin to the agency`s MedWatch program at (800) FDA-1088; fax: (800) FDA-0178.

In response to the removal of the drugs from the market, Wyeth-Ayerst Laboratories and Georgetown Univer-sity conducted a random, double-blind, multi-centered study involving 1,072 patients who had not previously taken either Fenfluramine or Dexfenfluramine within six months prior to the study. Cardiologists diagnosing patients` electrocardiograms did not know which patients had taken placebos and which patients had taken Fenfluramine or Dexfenfluramine.

The study demonstrated that there was no statistically significant increase in the prevalence of clinically-relevant heart-valve regurgitation, estimated pulmonary artery pressure, or serious cardiovascular effects following Fenflu-ramine or Dexfenfluramine usage for two to three months compared to placebo. In conclusion, patients who took the drugs for only two to three months can be reassured that it would be unlikely for them to have acquired valvular defects or pulmonary hypertension from the drugs.

During the time the drugs were on the market and prescribed, 76 percent of prescriptions were for 60 days, and 86 percent of prescriptions were for 90 days. Therefore, most of the patients who took the Fen-Phen combination did so in the so-called safe limited period of three months. Other reports from the FDA indicate that 30 percent of patients who had taken either Redux or Pondimin for three or more months are at risk for valvular heart damage. More research is necessary to determine the complete risk factors associated with Fen-Phen therapy. The Amercian Heart Association says that further research will demonstrate:

- incidence of significant valvular disorders

- valvular disorder risk levels for patients who have taken the combination for various time periods

- whether valvular disorders are reversible upon discontinuation of the drugs

The concern for dental professionals is determining who has taken Fen-Phen and who is at risk for such valve damage. It means we must not only ask patients what drugs they currently are taking, but what drugs they have taken in the past and how long they took the drugs.

The AHA states, "All persons who have taken Fenfluramine (Pondimin) or Dexfenfluramine (Redux) for any period of time should have a thorough medical history and cardiovascular physical examination."

Patients may be asymptomatic and still have significant regurgitation of a heart valve. Such patients would require prophylactic antibiotic before invasive dental procedures, including oral prophylaxis. The current regimen for prophylactic antibiotic against infective endocarditis applies (see "American Heart Association recommendations for prevention of infective endocarditis").

By April 1, 1998, a new prescription diet pill became available in the United States. Sibutramine (Meridia) has similar actions to Selective Serotonin Reuptake Inhibitors (SSRIs), such as Prozac, Zoloft, and other antidepressants. We will be seeing this drug on patients` medical histories. Because Meridia is a sympathomimetic drug, it may be synergistic with other sympathomimetic drugs used commonly as vasoconstrictors in local anesthesia.

A look at obesity

Despite of all the sugar-free and fat-free foods on the market, Americans are fatter than ever. Half of American adults are overweight and 20 percent of adolescents (ages 6-17) are overweight. When a woman has an excess of body fat that exceeds 30 percent of her total body weight, she is considered obese. A man whose body fat is 25 percent of his total body weight is considered obese.

Obesity is recognized now as a disease that is caused by several factors - genetic, environmental, psychological, and some that have yet to be discovered. What we do know is that obesity increases one`s risks for diseases, such as adult-onset diabetes, coronary artery disease, cerebrovascular accidents (strokes), several kinds of cancers, gallbladder disease, and mucoskeletal and respiratory disorders. With obesity having such a profound impact on a person`s degree of wellness and life span, it is no wonder that physicians across the country are trying to help their obese patients lose weight.

According to statistics, losing even a small amount of fat reduces risk factors for all types of diseases. The incentive for most people to lose weight is appearance. The psychological effects of not looking good and wanting to look good are the reasons half of American women diet and/or exercise, and one-fourth of American men diet and/or exercise. As we age, our metabolism slows down, our muscle mass is replaced with fat. Although we may not weigh much more than we did 10 years ago, we are not as toned.

Remember the days of dental hygiene school when you had to do nutritional counseling with most of your patients? If Americans are fatter than ever, we need to be doing more nutritional counseling than ever. Perhaps we should initiate a crusade to provide this service for a fee to help improve the statistics of obesity in America. And, of course, we could improve the statistics of obesity in our profession and other health-care professions. Role modeling is still an important professional image. Have a weight-loss plan to share with patients and colleagues (see "Identifying a good weight loss plan").

Use of weights during exercise

Muscle burns more calories than fat. That is the reason men can consume so many more calories than women and not gain weight as easily. Men naturally have more muscle mass than women, due to their testosterone levels. All forms of exercise help maintain muscle mass, but incorporating the use of weights in a routine workout increases one`s metabolism because muscle demands many more calories.

Individuals who participated in recent studies were placed on the same diets and an exercise routine. One group exercised without weights and the other with weights. The group using weights lost weight faster and was better able to maintain the weight loss than the group who did not use weights. In addition, maintaining muscle mass is important in supporting bone structure and function. Weight training and weight-bearing exercise are significant factors in the prevention of osteoporosis.

We are all interested in total wellness. With Americans being fatter than ever, there will be more appetite suppressants seen on medical histories. That means that risk factors involved in treating obese patients will require a better understanding of the treatment and prevention of obesity. We owe it to our patients to be sympathetic to the physical and psychological discomforts associated with obesity.


*Atkinson RL; et al; Long-term drug treatment of obesity in a private practice setting. Obes Res, 1997 Nov, 5:6, 578-86.

*Blackburn GL, et al; Pharmaceutical treatment of obesity. Nurs. Clin North Am, 1997 Dec, 32:4, 831-48.

*Connolly HM; et al; Valvular heart disease associated with fenfluramine-phentermine. N Engl J Med, 1997 Aug, 337:9, 581-8

*Green SM; Obesity prevalence, causes, health risks and treatment. Br J Nurs, 1997 Nov, 6:20, 1181-5.

*"Joint ACC/AHA Guidelines for the Clinical Application Echocardiography," Circulation, 1997 March, 95:1686-1744.

*Peters S; The new outlook on fat. Adv Nurs Prac 1998 Jan, 6:1, 47-50.

*Yanovski SZ, et al; Long term pharmacotherapy in the management of obesity. 1996 JAMA 276(23): 1907-1915.

Cynthia R. Biron, RDH, is chair of the dental hygiene program at the Tallahassee Community College. She also is a certified emergency medical technician.

American Heart Association recommendations for prevention of infective endocarditis

I. Standard Regimen Amoxicillin Adults, 2.0 grams (children, 50 mg/kg) orally 1 hour before procedure.

II. For Amoxicillin/Penicillin-Allergic Patients Clindamycin Adults, 600mg (children, 20mg/kg) orally 1 hour before procedure.


Cephalexin* or Cefadroxil* Adults, 2.0 grams (children, 50 mg/kg) orally 1 hour before the procedure.


Azithromycin or Clarithromycin Adults, 500mg (children, 15 mg/kg) orally 1 hour before procedure.

*Cephalosporins should not be used in patients with immediate-type hypersensitivity reaction to penicillin.

If unable to take oral medications, please contact physician so an alternative regimen can be prescribed.

Identifying a good weight-loss plan

The USDA and the National Institute of Diabetes and Digestive and Kidney Ideas (NIDDK), recommend choosing a diet that contains the following criteria:

(1) Lower in calories (300 to 500 calories fewer than daily normal), yet include 100 percent of the Recommended Daily Allowance (RDA) for vitamins.

(2) Slow, steady weight loss - no more than 1 to 2 pounds per week.

(3) Eat a variety of nutritious foods - no fad diets such as no carbohydrates.

(4) Fill up on foods high in fiber - such as fruits, vegetables, legumes, whole grains.

(5) Consume less than 30 percent of calories from fat.

(6) Participate in moderate exercise - 30 minutes per day.

- Consult your doctor if you plan to lose more than 15-20 pounds, have any health problems, or take medications.