Are There Risks to Taking These Medications?

When considering the use of long-term weight-loss medication treatment for obesity, the following possible concerns and risks should be discussed with your doctor:

Addiction. Currently, all prescription medications to treat obesity except Xenical are "controlled substances." This means that doctors are required to follow certain restrictions when prescribing them since they could be addictive.

Developed tolerance. Most people's weight tends to level off after 6 months while taking a weight-loss medication. This leads to a concern that the person has developed a tolerance for the medication. However, it is unclear whether this leveling off is indeed due to a developed tolerance or if the medication has reached its limit in effectiveness.

Side effects. Most side effects of weight loss medications are mild (although some can be unpleasant) and usually improve as your body adjusts to the medication. Rarely, serious and even fatal outcomes have been reported.

What Are the Side Effects?

Most appetite suppressants are used as a short-term treatment for people with obesity. Not only do the drugs' effects tend to wear off after a few weeks, but they can also have some unpleasant side effects, including: 

Increased heart rate
Increased blood pressure
Sweating
Constipation
Insomnia (inability to sleep or stay asleep)
Excessive thirst
Lightheadedness
Drowsiness
Stuffy nose
Headache
Anxiety
Dry mouth

Some side effects with Xenical include abdominal cramping, passing gas, leakage of oily stool, increased number of bowel movements and the inability to control bowel movements. These side effects are generally mild and temporary, but may be worsened by eating foods that are high in fat. Patients should start and maintain a low-fat diet (less than 30% of calories from fat) before starting treatment with Xenical. Because Xenical reduces the absorption of some vitamins, people taking Xenical should take a multivitamin at least 2 hours before or after taking the medication.

People with poorly controlled high blood pressure, heart disease, irregular heartbeat, or a history of stroke should not take Meridia. All people taking Meridia should have their blood pressure and heart rate monitored on a regular basis.

Because these drugs are not recommended for long-term use, it is important for people who are trying to lose weight to learn new eating habits and to exercise while the drug is still effective. Once healthy eating and regular exercise have been learned and established, it is important to continue eating right and exercising if you hope to continue losing weight and keep lost weight from returning.

Weight loss medications are not for everybody. For example, there are limited studies on these medications' effects on older adults and on children.

July 14, 2004 - LA Times: Ohio Court Dismisses Claims Against Abbott - manufacturers of Meridia - finding that the 113 plaintiffs failed to provide sufficient scientific evidence to support claims that the drug caused various health problems, including 49 allegedly Meridia induced heart related deaths, high blood pressure, birth defects and miscarriages.