Prescription medications are an option in helping people lose weight who have an increased medical risk because of their obesity. However, these drugs are not a cure-all and they are most often useful in producing a rapid initial weight loss. The use of weight-loss medications to treat obesity should be combined with physical activity and improved diet to lose and maintain weight successfully over the long term.

Currently, most available weight-loss medications approved by the U.S. Food and Drug Administration (FDA) are for short-term use, meaning a few weeks or months. Meridia® (sibutramine) and Xenical® (orlistat) are the only weight-loss medications approved for longer-term use in obese patients, although the safety and effectiveness of these drugs have not been established for use beyond one year.

Meridia® is an appetite suppressant. Appetite-suppressant medications promote weight loss by decreasing appetite or increasing the feeling of being full. These medications decrease appetite by increasing serotonin or catecholamine--two brain chemicals that affect mood and appetite.

Xenical® is a fat-absorption inhibitor. Fat-absorption inhibitors work by preventing your body from breaking down and absorbing fat eaten with your meals. This unabsorbed fat is then eliminated in bowel movements.

In general, Xenical® and Meridia® are moderately effective, leading to an average weight loss of 5 to 22 pounds more than what would be expected with non-drug treatments. However, the response to these medications is based on each individual, and some people experience more weight loss than others. Likewise, there is no one correct dose for these medications. Your doctor will decide what works best for you based on his or her evaluation of your medical condition and your response to treatment.

Some people have lost more than 10 percent of their initial body weight with the help of prescription medications. This is a large enough amount to reduce the risk of high blood pressure, diabetes and other obesity-related health complications. Patients generally experience a maximum weight loss within 6 months of starting medication treatment.

Over the short term, weight loss due to prescription drugs may reduce a number of health risks in obese individuals. However, there are currently no studies to determine the effects of these medications over the long term.

Are there any risks involved in taking these medications?
When considering the use of long-term weight-loss medication treatment for obesity, the following possible concerns and risks should be considered.

• Potential for 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. Dependence on non-amphetamine weight loss medications is not common, however, it is something to keep in mind when taking these medications.
• Developing a tolerance: Most people's weight tends to level off after 6 months while still 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 and usually improve as your body adjusts to the medication. Rarely, serious and even fatal outcomes have been reported. Two appetite-suppressant medications (fenfluramine, dexfenfluramine) that affect serotonin release and reabsorption have been withdrawn from the market due to their link to heart valve disease.

Meridia® (sibutramine) acts on both the serotonin and catecholamine systems. The most common side effects of Meridia® are increased blood pressure and pulse, which are usually slight but can be significant in some patients. People with poorly controlled high blood pressure, heart disease, irregular heartbeat or a history of stroke should not take Meridia®. All patients taking Meridia® should have their blood pressure monitored on a regular basis. Other common side effects of Meridia® are:

• Anxiety
• Constipation
• Dryness of the mouth
• Trouble sleeping
• Stuffy or runny nose
• Dizziness
• Headache

Some side effects with Xenical® (orlistat) include oily spotting, gas with discharge, urgent need to go to the bathroom, oily or fatty stools, an oily discharge, 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. Because Xenical® reduces the absorption of some vitamins, patients should take a multivitamin at least 2 hours before or after taking the medication.

In the event that any of the following symptoms occur, you should call your doctor as soon as possible:

• Achiness
• Chills
• Irregular heartbeat
• Painful menstruation
• Swelling of the body or of the feet and ankles

What should I discuss with my medical provider before considering these medications?
With either Xenical® or Meridia®, it is important that you notify your physician if you:

• Are pregnant or breastfeeding
• Have allergies to dyes, foods or medications
• Are taking any diet supplements, including any herbal products
• Have a history of drug or alcohol abuse
• Have a history of an eating disorder
• Have gallbladder problems
• Have a history of depression or manic depressive disorder
• Use of monoamine oxidase (MAO) inhibitors or antidepressant medications
• Have migraine headaches requiring medication
• Have glaucoma
• Have diabetes
• Have heart disease or heart condition, such as an irregular heart beat
• Have high blood pressure
• Are planning to have surgery that requires general anesthesia

Are there any other precautions that should be taken when using Xenical® or Meridia®?
Follow the directions on your prescription label carefully. If there is any part that you do not understand, ask your doctor or pharmacist. Do not take any more or less than prescribed. Do not take it more often than prescribed.

If you miss a dose, simply take it as soon as possible. However, if it is close to when you are scheduled to take your next dose, simply skip the missed dose and proceed with your regular schedule. Do not take a double dose. These medications should be kept in the original container, tightly sealed and away from children. They should be stored at room temperature, away from excess heat and moisture (not in the bathroom or near the kitchen sink). Any medication that is outdated or unused should be thrown away.

© Copyright 1995-2007 The Cleveland Clinic Foundation. All rights reserved

This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. For additional written health information, please contact the Health Information Center at the Cleveland Clinic (216) 444-3771 or toll-free (800) 223-2273 extension 43771 or visit www.clevelandclinic.org/health/.

index#947575