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 1995-2009 The Cleveland Clinic Foundation. All rights reserved.
Can't find the health information you’re looking for?
Ask a Health Educator, Live!
Know someone who could use this information?...send them this link.
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. This document was last reviewed on: 11/15/2006...#9475
