New Weight Loss Assistant: Can you tell me about the new drug for weight loss that was recently approved by the FDA?

Yes. This medication is called Plenity. It is quite unique in some regards as, unlike many previous weight loss drugs, it's not a stimulant and it does not have central nervous system side-effects. That means it can be used regardless of an individual's blood pressure, cholesterol issues or type 2 diabetes, something previous medications didn't offer. It should, however, be used in combination with diet and exercise.

The medication has a unique mechanism of action. It contains a cellulose (which is of course found in plants) and citric acid (found in citrus fruits). The capsules are taken with water before lunch or dinner. Once in the gastrointestinal tract, the capsules release the ingredients, which rapidly absorb water, form cross-links and swell up. The resulting aggregates of gel have a very similar consistency to plant-based foods and "trick" the body into feeling full. The active ingredients are not absorbed into the body and because of this there are fewer concerns with side-effects. Also, the active ingredients are compounds that we frequently consume with vegetables and fruits. Most reported side-effects with Plenity occurred at rates similar to those seen with placebo. Approximately four out of 10 patients did report a gastrointestinal side-effect such as distension, diarrhea, constipation or abdominal pain. These issues were generally very mild and did not result in the patient discontinuing the medication.

The outcomes are the most exciting part of this story. In the clinical trials evaluating this medication, six out of 10 adults experienced at least a 5 percent weight loss. The average weight loss was 10 percent of body weight or about 22 pounds. Also about one out of four patients lost an average of 14 percent of their body weight or 30 pounds.

These results are quite extraordinary compared to most other weight loss medications. Given the very acceptable side-effect profile and the positive results that most people experience when taking Plenity, it is likely to be a quite successful medication for many people.

John R. White is chair of the Department of Pharmacotherapy at WSU-Spokane.