New drugs may be future of weight-loss treatment

Two new drugs, one already approved by the U.S. Food and Drug Administration (FDA) and the other awaiting approval, may successfully fill the void left by the market withdrawal of Redux and Pondimin.

Meridia (sibutramine), marketed by Knoll Pharmaceutical Co. in Mt. Olive, NJ, was approved by the FDA in November. The drug suppresses the reuptake of neurotransmitters such as serotonin and norepinephrine that are believed to regulate appetite, producing a feeling of fullness. The drug's mechanism is different from that of Redux and Pondimin, and clinical trials have shown no signs of potential for inducing heart valve problems. It's available in a once-a-day capsule in three doses. Side effects seen so far are mild and include dry mouth, constipation, and headache.

However, FDA medical officer Eric Colman, MD, says Meridia has the potential to substantially increase blood pressure. Regular monitoring of blood pressure is required, and patients who have uncontrolled hypertension or previous history of stroke or heart disease should not take the drug. With proper use of Meridia, some patients may see significant weight loss of 10% to 15% of their body weight. "For some obese patients, this drug will be helpful," Colman says. "But very few people will lose a tremendous amount of weight on this drug alone. It's still necessary to have a proper diet and regular exercise along with the drug."

Colman says the only way to prevent a recurrence of the fen/phen problem is for physicians to follow the labeling information. Meridia is indicated for 12-month use in patients who have a body mass index of at least 30 or at least 27 if they have comorbid conditions. It should not be used in combination with any serotonin drugs such as antidepressants. "With every drug, there's always the potential for an unforeseen side effect appearing after the drug is on the market and is exposed to a large number of patients," Colman says. "With fen/phen, no one had any inkling there would be a problem with valvular disease. If a side effect is rare, you're not likely to see it when you're studying only 1,000 patients in trials."

Education program offered

One unique aspect of Meridia is a year-long patient education program called "Point of Change" offered by Knoll to each person who takes the drug, says Linda Mayer, Knoll's communications director. Patients begin by filling out a brief personal assessment that asks questions about such issues as their experience with weight loss and their physical activity preferences. Based on the results, materials are tailored to each individual. A personalized monthly newsletter, for example, offers recipes based on what that person likes to eat. Patients are also given a toll-free number they can call for ongoing support and referrals to resources.

The other new drug, Xenical (orlistat), marketed by Nutley, NJ-based Hoffman-La Roche, is awaiting FDA approval. In March, members of the FDA's Endocrinologic and Metabolic Drugs Advisory Committee tied on recommending approval, but the company still hopes full FDA approval will come by the end of the year.

Xenical is a lipase inhibitor that acts in the gastrointestinal tract to block the absorption of fat by approximately 30%. The drug has been well-tolerated in clinical trials, with the most common side effect being one or two episodes of excess fat clearance through the gastrointestinal tract.

[For more information on Meridia, contact Knoll Pharmaceutical Co., Mt. Olive, NJ. Telephone: (973) 426-2600. For information on Xenical, contact Hoffman-La Roche, 340 Kingsland St., Nutley, NJ. 07110-1199. Telephone: (800) 887-3900.]