Obesity Medications
Like diabetes or high blood pressure, Obesity is considered a chronic disease.
Obesity can be dangerous to an individual as the risk of developing serious disease is increased.
And, Obesity can affect society both directly and indirectly. Directly, there are the costs associated with the treatment of obesity. Indirectly, there may be losses in productivity as a result of illness, disability, or, even premature death.
Chronic disease, dangerous, and costly – three descriptions that don’t exactly depict obesity in a positive way. Three descriptions, in fact, that are pretty powerful reasons to treat obesity.
But, just how can obesity be treated? Because it is a chronic disease, treatment, often times, may need to be continued for years to improve health and maintain a healthy weight.
Currently, treatment options include:
- Diet – Various studies show low fat and low calorie diets as effective means to reduce weight.
- Behavioral Modification – Reconditioning a patient’s attitude to food or exercise can be effective.
- Surgery – Gastroplasty or gastric bypass is used as a means for weight loss in patients with a BMI of 40 and over, or those with a BMI of 35 and associated high-risk conditions. But, surgical intervention for obesity is expensive, and has serious long-term effects.
- Drug Treatments – For obese people who have difficulty losing weight through diet and exercise alone, there are a number of FDA approved prescription drugs that may help.
- Please note: Phentermine.com is dedicated to the weight loss medicine Phentermine, therefore, we will devote the remainder of this section to weight loss medications as a treatment for obesity.
Medications That Promote Weight Loss
Prescription weight-loss medications should be used only by patients at increased medical risk because of their obesity – persons with a BMI of 30 and above, or 27 and above if they have other risk factors, such as high blood pressure or diabetes. They should not be used for “cosmetic” weight loss.
Weight-loss medications work best when combined with a weight-management program that helps you improve your eating and physical activity habits.
Most currently available weight-loss medications are FDA approved for the short-term treatment (a few weeks or months) of obesity. Sibutramine and Orlistat are FDA approved for the longer-term use in significantly obese patients. Information is limited concerning the safety and effectiveness of weight-loss medications during many years of use.
The generic and trade names of all the prescription weight-loss medications are detailed in the following table:
FDA approval received | Generic name | Trade name(s) |
1996 | Dexfenfluramine + | Redux (withdrawn) |
1998 | Diethylpropion | Tenuate, Tenuate Dospan |
1973 | Fenfluramine + | Pondimin (withdrawn) |
1992 | Mazindol | Sanorex, Mazanor |
1999 | Orlistat * | Xenical |
1998 | Phendimetrazine | Bontril |
1959 | Phentermine | Adipex-P, Ionamin, Fastin |
1997 | Sibutramine * | Meridia |
(+) withdrawn from the market
(*) FDA approved for long-term use
All of the prescription weight-loss drugs, except Orlistat (Xenical), work by suppressing the appetite (called appetite-suppressant medicines). Appetite-suppressants decrease appetite by increasing serotonin or catecholamine – two brain chemicals that affect mood and appetite.
Xenical, approved by the FDA in 1999, is the first in a new class of anti-obesity drugs known as lipase inhibitors. Lipase is the enzyme that breaks down dietary fat for use by the body. Xenical interferes with lipase function, decreasing dietary fat absorption by 30 percent. Since undigested fats are not absorbed, there is less calorie intake, which may help in controlling weight.
Meridia (Sibutramine), FDA approved in 1997, increases the levels of certain brain chemicals that help reduce appetite. Because it may increase blood pressure and heart rate, people with uncontrolled high blood pressure, a history of heart disease, congestive heart failure, irregular heartbeat, or stroke, should not use Meridia.
In September 1997, the FDA requested the withdrawal of Fenfluramine (Pondimin and others) and Dexfenfluramine (Redux). Findings in the summer of 1997 suggested the two medications were the likely cause of heart valve problems. The FDA recommended that people taking the drugs stop and that they contact their doctor to discuss their treatment. For further information, please click here.
Off-Label Use
FDA regulations place strict restrictions on how a medication can be advertised or promoted by the manufacturer. The FDA can NOT restrict, however, a doctor’s ability to prescribe the medication for different conditions, in different doses, or for different lengths of time. Once the agency has approved a drug, doctors may prescribe it at will. The practice of prescribing medication for periods of time or for conditions not approved is known as “off-label” use.
One example of off-label use is the use of more than one weight-loss medication at a time (called a combined drug treatment). A second example is using a weight-loss medication other than Sibutramine or Orlistat for more than a short period of time (i.e., more than “a few weeks”).
While off-label use often occurs in the treatment of many conditions, you should feel comfortable asking your doctor if he or she is using a medication or combination of medications in a manner not approved by the FDA.
Single Drug Treatment
In general, weight loss medications are modestly effective, leading to an average weight loss of 5 to 22 pounds above that expected with non-drug obesity treatments.
People respond differently to weight-loss medications, some people experience more weight loss than others. A loss of more than 10% of the starting body weight may reduce risk factors for obesity-related diseases, such as high blood pressure or diabetes.
Maximum weight loss usually occurs within 6 months of starting medication treatment. Weight then tends to level off or increase during the remainder of treatment. Studies suggest that if a patient does not lose at least 4 pounds over 4 weeks on a particular medication, then that medication is unlikely to help the patient achieve significant weight loss.
Most studies show that the majority of patients who stop taking weight-loss medications regain the weight they had lost. Maintaining healthy eating and physical activity habits will increase your likelihood of keeping weight off.
Few studies have looked at how safe or effective these medications are when taken for more than one year. Both Orlistat and Sibutramine have been studied for as long as two years in some patients.
Some antidepressant medications have been studied as appetite-suppressant medications. While these medications are FDA approved for the treatment of depression, their use in weight loss is an “off-label” use. Studies of these medications generally have found that patients lost modest amounts of weight for up to 6 months. However, most studies have found that patients who lost weight while taking antidepressant medications tended to regain weight while they were still on the drug treatment.
There is no one correct dose for weight loss medications. A consultation with a qualified doctor/healthcare provider will determine what works best for you based on a thorough evaluation of your medical condition and response to treatment.
Combined Drug Treatment
The combined drug treatments (or cocktails) of “Fen-Phen” – Fenfluramine (Pondimin) and Phentermine, and “Dexfen-Phen” – Dexfenfluramine (Redux) and Phentermine are no longer available. Reports of valvular heart disease in association with Fenfluramine (Pondimin) and Dexfenfluramine (Redux) led to the withdrawal of these two medications from the market.
The newest combined drug treatment is “Phen-Pro”, a combination of Phentermine and Prozac. Zoloft, Celexa, Luvox, Trazadone or Effexor may be used in lieu of Prozac. The combination is considered an “off-label” use.
The use of the antidepressant in the Phen-Pro cocktail is unrelated to depression. The cocktail is necessary because the effects of Phentermine, when used alone, lessen over time. The Phen-Pro cocktail enables Phentermine to work better and for a longer period of time. The cocktail does not appear to cause the problems that resulted from the usage of Fen-Phen.
For further information on Phen-Pro, we suggest the following article from the American Medical Association (AMA).
Little information is available about the safety or effectiveness of other drug combinations for weight loss, including Fluoxetine (Prozac)/Phentermine, Phendimetrazine/Phentermine, Xenical/Sibutramine, herbal combinations, or others. Until more information on their safety or effectiveness is available, using combinations of medications for weight loss is not recommended except as part of a research study.
Potential Benefits of Medication Treatment
Over the short term, weight loss in obese individuals may reduce a number of health risks. Studies looking at the effects of weight-loss medication treatment on obesity-related health risks have found that some agents lower blood pressure, blood cholesterol, and triglycerides (fats) and decrease insulin resistance (the body’s inability to use blood sugar) over the short term. Long-term studies are still needed to determine if weight loss from weight-loss medications can improve health.
Potential Risks and Concerns When Considering Medication
In considering a long-term weight-loss medication treatment for obesity, these potential risks and concerns should be considered:
- Potential for Abuse or Dependence
Currently, all prescription medications to treat obesity, except Orlistat, are controlled substances, meaning doctors must follow certain restrictions while prescribing many weight-loss medications. Although abuse and dependence are not common with non-amphetamine appetite-suppressant medications, doctors should take caution when prescribing these medications for patients with past history of alcohol or other drug abuse. - Development of Tolerance
Most studies of weight-loss medications show that a patient’s weight tends to level off after 4 to 6 months while still on medication. While some patients and physicians may be concerned that this shows tolerance to the medications, the leveling off may mean that the medication has reached its limit of effectiveness. Based on currently available studies, it is unclear if weight gain with continuing treatment is due to drug tolerance. - Reluctance to View Obesity as a Chronic Disease
Obesity is often viewed as the result of a lack of willpower, weakness, or a lifestyle “choice” – the choice to overeat and underexercise. The belief that persons choose to be obese adds to the hesitation of health professionals and patients to accept the use of long-term appetite-suppressant medication for the management of obesity. Obesity, however, is more appropriately considered a chronic disease than a lifestyle choice. Other chronic diseases, such as diabetes and high blood pressure, are managed by long-term drug treatment, even though these diseases also improve with changes in lifestyle, such as diet and exercise. Although this issue may concern physicians and patients, social views on obesity should not prevent patients from seeking medical treatment to prevent health risks that can cause serious illness and death. Appetite-suppressant medications cannot take the place of improvements in one’s diet or level of physical activity. The major role of weight-loss medications appears to be to help a person stay on a diet and exercise plan to lose weight and keep it off. - Side Effects
Because weight-loss medications are used to treat a condition that affects millions of people, many of whom are basically healthy, their potential for side effects is of great concern. Most side effects of these medications are mild and usually improve with continued treatment. Rarely, serious and even fatal outcomes have been reported. Two approved appetite-suppressant medications that affect serotonin release and reuptake have been withdrawn from the market (Fenfluramine, Dexfenfluramine). Medications that affect catecholamine levels (such as Phentermine, Diethylpropion, and Mazindol) may cause symptoms of sleeplessness, nervousness, and euphoria (feeling of well-being).Sibutramine acts on both the serotonin and catecholamine systems, but unlike Fenfluramine and Dexfenfluramine, Sibutramine does not cause release of serotonin from cells. The primary known side effects of concern with Sibutramine are elevations in blood pressure and pulse (usually small but may be significant in some patients). People with poorly controlled high blood pressure, heart disease, irregular heartbeat, or history of stroke should not take Sibutramine, and all patients taking the medication should have their blood pressure monitored on a regular basis.
Some side effects associated with 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 inability to control bowel movements. These side effects are generally mild and temporary, but may be worsened by eating foods high in fat. Since Orlistat reduces the absorption of some vitamins, patients are recommended to take a multivitamin at two hours before or after taking Orlistat.
Please visit our Overview of Phentermine to learn side effects associated with Phentermine.
Primary Pulmonary Hypertension (PPH) is a rare but potentially fatal disorder that affects the blood vessels in the lungs and results in death within 4 years in 45 percent of its victims. It should be noted that the vast majority of cases of PPH have occurred in patients who were taking Fenfluramine or Dexfenfluramine, either alone or in combination. There have been only a few case reports of PPH in patients taking Phentermine alone; although the possibility that Phentermine alone may be associated with PPH cannot be ruled out. No cases of PPH have been reported with Sibutramine, but because of the low incidence of this disease in the underlying population, it is not known whether or not Sibutramine may cause this disease.
Consult a Doctor Prior to Choosing a Weight-Loss Medication
Prior to selecting a weight-loss medication, please consult a doctor or other qualified health professional. Voice any concerns that you may have. Your physician will determine if you are a good candidate for prescription weight-loss medication.
He/she will make his determination based on the following factors:
- Complete physical examination
- Family history of illnesses related to overweight (i.e. – type 2 diabetes mellitus and heart disease)
- Methods you have used to lose weight in the past
- Your complete medical history
- Your personal weight history
- Your risk for obesity-related health problems by measuring your blood pressure and doing blood tests.
Please inform the physician if you have any of the following medical conditions:
- Diabetes
- Glaucoma
- Heart disease or heart condition, such as an irregular heart beat
- High blood pressure
- History of an eating disorder
- History of depression or manic depressive disorder
- History of drug or alcohol abuse
- Migraine headaches requiring medication
- Planning to have surgery that requires general anesthesia
- Pregnancy or breast-feeding
- Use of monoamine oxidase (MAO) inhibitors or antidepressant medications
If your doctor determines that you have obesity-related health problems or are at high risk for such problems, and if you have been unable to lose weight or maintain weight loss with nondrug treatment, he or she may recommend that you use prescription weight-loss medications.
Appropriate Treatment Goals for Using Prescription Weight-Loss Medications
If you and your doctor believe that the use of weight-loss medications may help you, discussing the goals of treatment is important. Improving your health and reducing your risk for disease should be the primary goals.
For most severely obese people, achieving an “ideal body weight” is both unrealistic and unnecessary to improve their health and reduce their risk for disease. Even a modest weight loss of 5 – 10 % of your starting body weight can improve your health and reduce your risk factors for disease.
Weight-loss medications should be used in conjunction with proper dietary and exercise habits. Any modifications in your diet and physical activity must be developed and continued over the long term to maintain the weight loss. See/speak to your physician regularly so that s/he can monitor your response to the medication, not only in terms of weight loss, but how it affects your overall health.
Long-term use of prescription weight-loss medications may be helpful for carefully selected individuals, but little information is available on the safety and effectiveness of these medications when used for more than 2 years. By evaluating your risk of experiencing obesity-related health problems, you and your physician can make an informed choice as to whether medication can be a useful part of your weight-management program.
For further information on the prescription weight-loss medication, Phentermine, please visit our Overview section.