Prescription Diet Pills

Prescription weight loss pills

Research about prescription weight loss drugs is much more prevalent and credible due to the far stricter controls imposed on these drugs. At least there are long-term medical studies and FDA jurisdiction. However, just because these products have FDA approval doesn't actually mean they work -- or work without side effects that may render continued use unpleasant. Furthermore, the FDA's recent approval of orlistat (Xenical) for over-the-counter use has many watchdog organizations concerned.

The medications that are currently available for prescription weight loss are phentermine (under several trade names including Adipex-p, Obenix and Oby-Trim), sibutramine (Meridia in the U.S. and Reductil in Europe) and orlistat (Xenical). These medications are approved for people who are obese -- defined as having a body mass index (BMI) of 30 or more.

Another drug, rimonabant (sold in Europe as Acomplia) was to be sold in the United States under the trade name Zimulti. In June 2007, however, a 14-member FDA panel voted against its approval, saying manufacturer Sanofi-Aventis had failed to demonstrate the drug's safety. Included in the hearing was testimony suggesting a link between rimonabant and an increased risk of depression, anxiety and suicidal thoughts. Sanofi-Aventis has since withdrawn its application to have rimonabant approved in the United States.

Do prescription diet drugs work? Here again, the answer isn't simple. In a WebMD study, obese people who modified their eating and exercise habits and took the prescription drug Meridia actually lost more weight than those who took the drug alone or those who only modified their eating and exercise habits. The group using Meridia in combination with diet and exercise lost an average of 26 pounds in a year. That breaks down to a weight loss of about two pounds per month -- that's about what fitness experts say you can expect from diet and exercise alone. Unfortunately, we have no idea what happened to the people in the study after they stopped taking Meridia.

Meridia affects a person's feeling of fullness, so they feel satisfied eating less food. It also prevents metabolism from slowing down even in the face of consuming fewer calories. Studies say the positive effects of Meridia tend to max out at six months and it can contribute to high blood pressure, which must be carefully monitored. Some doctors describe it as hit or miss. In outlining the pros and cons of Meridia in 2004, HealthFacts pointed to eleven clinical trials ranging from 12 to 52 weeks in which persons taking Meridia at varying doses lost an average of ten to 14 pounds over a year. Any weight loss is positive, of course, but that's roughly one pound per month. The article also points out that weight lost was regained when patients stopped taking the medication.

Orlistat (trade name Xenical) works by blocking fat absorption so that it moves through the intestine undigested. The idea of a fat blocker sounds good in theory until you consider the not-so-pleasant side effects, which include sudden diarrhea and "leakage." Those side effects go down as your fat intake does. Several articles we read suggested ironically that Xenical may work best as a deterrent, whereby eating less fat you have a reduced chance of nasty side effects. Clinically, Xenical produces similar results to Meridia, so we're talking about one pound per month on average over the course of a year.

In recent years, the consumer advocacy group Public Citizen has called for the FDA to pull both Meridia and Xenical from the shelves. In the case of Meridia, Public Citizen cites 49 deaths from cardiac arrest linked to the drug and 124 reports of cardiac problems developed by those taking the drug. With Xenical it is the threat of colon cancer that is cause for concern, as Xenical has been shown to increase aberrant crypt foci (ACF) cells in the colon in rats. ACF cells are widely thought to be a precursor to colon cancer. Xenical also has those aforementioned side effects that make the drug difficult for many people to tolerate. Consumer Reports has written articles about both medications and says you'd do better to stick with old-fashioned diet and exercise. The risks are not worth the relatively minor benefits.

The cross from prescription to over-the-counter is one that several drug companies are making an attempt to do. The recent FDA approval of Xenical for over-the-counter use (at 50 percent its prescription strength) has been eagerly anticipated by its makers for the past couple of years. Alli, as the OTC Xenical is called, has been selling well since it hit the shelves in June 2007. Though it is not intended for use by persons under the age of 18, and is meant to be used in conjunction with a reduced-calorie diet and exercise regimen, one wonders how the age recommendation will be monitored.

With the less-than-stellar clinical performance of Xenical in the eyes of many health experts, it's not surprising that much of the reaction to Alli's approval by the FDA was negative. Public Citizen called Alli's approval "reckless," and ConsumerAffairs.com's health advisors counsel caution. CNN's Dr. Sanjay Gupta issued a list of "10 things to think about before taking this drug," ending with, "Expect modest weight loss, and by the way, the weight loss plateaus after six months."

Since before Alli came on the market, its gastrointestinal side effects have been well publicized. In particular, some critics question the usefulness of a diet drug that can be tolerated by most users only in conjunction with a low-fat diet. GlaxoSmithKline gets around the issue by marketing Alli as part of a complete weight loss system incorporating the drug, a user support forum and an online program called "myalliplan." Because of Alli's side effects (referred to as "treatment effects"), potential customers are warned to assess their level of commitment to a low-fat diet before they decide to use the drug. Those who do are encouraged to buy an Alli starter kit (*Est. $45 to $120, depending on the number of pills) which includes a bottle of capsules, a carrying case, six information booklets and a code to access myalliplan.

Users posting to Amazon.com and Drugstore.com give Alli mixed reviews. While some dieters say the drug helps with weight loss, others say they find it ineffective. Even many of the most positive reviews mention the drug's side effects. Several users say that the potential for oily spotting or other bowel issues helps them remember to keep the fat content of meals within the recommended limit of 15 grams. Others say they find the side effects inconvenient, embarrassing and even physically painful. One user points out that amount of fat typically blocked represents just over 100 calories a day, limiting Alli's potential contribution to at best a pound of weight loss per month.

Mayo Clinic specialist Donald Hensrud, M.D.'s assessment is even more modest. He estimates that Alli could contribute to a weight loss of about three pounds a year to the eight pounds consumers could expect to lose through diet and exercise alone. He also advises users to take a daily multivitamin to help make up for the drug's negative effect on absorption of fat-soluble vitamins like A, D, E, K and beta carotene.

The FDA's own approval statement for Alli is hardly a glowing endorsement: "We know that being overweight has many adverse consequences including an increase in the risk of heart disease and type 2 diabetes. OTC orlistat, along with diet and exercise, may aid overweight adults who seek to lose excess weight and improve their health." The FDA website lists the side effects for Alli and Xenical (orlistat) but mentions nothing of studies showing possible links to colon cancer. All things said, Alli is an over-the-counter weight loss aid for which we do have clinical data. Its known side effects have at least been documented. Still, diarrhea and flatulence are one thing, and an increased risk of colon cancer, if the Public Citizen's petitions are correct, is quite another.

Phentermine diet pills are the old-school appetite suppressants that have been around for years. They are chemically similar to amphetamines, or stimulants, that suppress the appetite and cause you to eat less. Back in the 80s, the combo Fen-Phen (phentermine plus fenfluramine) was thought to be a highly effective diet drug for a couple of years until studies linked fenfluramine to heart valve disease and the FDA asked that it be pulled from the market. On its own, phentermine can work to suppress the appetite and provide a short-term weight loss boost to obese persons. Phentermine is designed to be used in conjunction with a calorie-restricted diet and exercise regimen, and it's indicated for usage of less than 12 weeks. When taken for periods of longer than 12 weeks, phentermine can raise blood pressure and become addictive.

Surprisingly, there are not that many clinical studies of phentermine by itself, despite its having been around since the 1950s. Plenty of studies were done of the drug in combination with fenfluramine, but it was rarely studied on its own. In a study of 108 people by McMaster University, phentermine produced an additional 5.8 pounds of weight loss more than a placebo over a nine-month period. In a 2004 Korean study, phentermine produced an additional eleven pounds of weight loss as compared to a placebo over the course of a five-month trial. For someone who is clinically obese, phentermine combined with diet and exercise could be segued into a sustainable diet and exercise plan, but blood pressure and addictive response must be closely monitored by a physician.