Health Guide
Drug Guide

Appetite suppressant, sympathomimetic (Oral route)

Brand Names:

Dosage Forms:

Uses of This Medicine:

Sympathomimetic appetite suppressants are used in the short-term treatment of obesity. Their appetite-reducing effect tends to decrease after a few weeks. Because of this, these medicines are useful only during the first few weeks of a weight-loss program. The sympathomimetic appetite suppressants can help you to lose weight while you are learning new ways to eat and to exercise. Changes in eating habits and activity level must be developed and continued long-term in order for you to continue losing weight and to keep the lost weight from returning.

These medicines are available only with your doctor's prescription.

You must follow a reduced-calorie diet while using an appetite suppressant in order to lose weight. Also, in order to keep the lost weight from returning, changes in diet and exercise must be continued after the weight has been lost.

Before Using This Medicine:


Tell your doctor if you have ever had any unusual or allergic reaction to medicines in this group or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.


Studies on these medicines have been done only in adult patients, and there is no specific information comparing use of sympathomimetic appetite suppressants in children with use in other age groups. The use of these medicines by children younger than 16 years of age is not recommended.

Older adults

Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of appetite suppressants in the elderly with use in other age groups.


If a pregnant woman takes this medicine in high doses or more often than the doctor has directed, it may cause withdrawal symptoms in the newborn baby. Also, medicines similar to sympathomimetic appetite suppressants can cause birth defects in the newborn baby if a pregnant woman takes them in high doses. Before taking this medicine, make sure your doctor knows if you are pregnant or if you may become pregnant.


Diethylpropion and benzphetamine pass into breast milk. It is not known if other sympathomimetic appetite suppressants pass into breast milk. However, use of sympathomimetic appetite suppressants during breast-feeding is not recommended, because it may cause unwanted effects in nursing babies.

Other medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking any of these medicines, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using medicines in this class with any of the following medicines is not recommended. Your doctor may decide not to treat you with a medication in this class or change some of the other medicines you take.

Using medicines in this class with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

Other interactions

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other medical problems

The presence of other medical problems may affect the use of medicines in this class. Make sure you tell your doctor if you have any other medical problems, especially:

Proper Use of This Medicine:

In order to prevent trouble in sleeping, if you are taking:

For patients taking a long-acting form of this medicine:

For patients taking mazindol:

Take this medicine only as directed by your doctor . Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered. If too much is taken, it may cause unwanted effects or become habit-forming.

If you think this medicine is not working properly after you have taken it for a few weeks, do not increase the dose. Instead, check with your doctor.


The dose medicines in this class will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of these medicines. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

Missed dose

If you miss a dose of this medicine, skip the missed dose and go back to your regular dosing schedule. Do not double doses.


Keep out of the reach of children.

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Do not keep outdated medicine or medicine no longer needed.

Precautions While Using This Medicine:

Your doctor should check your progress at regular visits to make sure that this medicine does not cause unwanted effects.

If you think this medicine is not working properly after you have taken it for a few weeks, do not increase the dose. Instead, check with your doctor.

Do not take an appetite suppressant with or less than 14 days after taking a monoamine oxidase (MAO) inhibitor. If you do, you may very suddenly develop extremely high blood pressure.

Taking a sympathomimetic appetite suppressant may cause a positive result in urine screening tests for amphetamines.

Sympathomimetic appetite suppressants may cause dryness of the mouth. For temporary relief, use sugarless candy or gum, melt bits of ice in your mouth, or use a saliva substitute. However, if your mouth continues to feel dry for more than 2 weeks, check with your medical doctor or dentist. Continuing dryness of the mouth may increase the chance of developing dental disease, including tooth decay, gum disease, and fungus infections.

This medicine may cause some people to feel a false sense of well-being or to become dizzy, lightheaded, drowsy, or less alert than they are normally. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or are not alert.

Before having any kind of surgery, dental treatment, or emergency treatment, tell the medical doctor or dentist in charge that you are using this medicine. Taking appetite suppressants together with medicines that are used during surgery or dental or emergency treatments may cause serious side effects.

Check with your doctor immediately if you notice a decrease in your ability to exercise, if you faint, or if you have chest pain, swelling of your feet or lower legs, or trouble in breathing. These may be symptoms of very serious heart or lung problems.

If you have been taking this medicine for a long time or in large doses and you think you may have become mentally or physically dependent on it, check with your doctor.

For patients with diabetes:

If you have been taking this medicine in large doses or for a long time, do not stop taking it without first checking with your doctor. Your doctor may want you to reduce gradually the amount you are taking before stopping completely. This will help prevent withdrawal side effects.

Side Effects of This Medicine:

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

Chest pain
decreased ability to exercise
swelling of feet or lower legs
trouble in breathing

Check with your doctor as soon as possible if any of the following side effects occur:

More common
Increased blood pressure
Less common or rare
Difficult or painful urination
fast or irregular heartbeat
feeling that others can hear your thoughts
feeling that others are watching you or controlling your behavior
hallucinations (feeling, seeing, or hearing things that are not there)
headache (severe)
mental depression
numbness, especially on one side of the face or body
skin rash or hives
sore throat and fever (with diethylpropion)
talking, feeling, and acting with excitement and activity you cannot control
unusual bleeding or bruising (with diethylpropion)
Symptoms of overdose
Abdominal or stomach cramps
convulsions (seizures)
diarrhea (severe)
dizziness, lightheadedness, or fainting
fast breathing
feeling of panic
hallucinations (seeing, hearing or feeling things that are not there)
high or low blood pressure
hostility with urge to attack
irregular heartbeat
nausea or vomiting (severe)
overactive reflexes
trembling or shaking
tiredness, weakness, and mental depression following effects of excitement

Abuse of a sympathomimetic appetite suppressant (taking the medicine in larger doses or taking it more frequently or for a longer time than the doctor ordered) can cause the following side effects:

Changes in personality
excessive, excited activity
irritability (severe)
mental illness (severe), similar to schizophrenia
skin disease
trouble in sleeping (severe)

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common
dizziness or lightheadedness
dryness of mouth
false sense of well-being
nausea or vomiting
nervousness or restlessness
stomach cramps or pain
trembling or shaking
trouble in sleeping

After the stimulant effects have worn off, drowsiness, unusual tiredness or weakness, or mental depression may occur.

Less common or rare
Blurred vision
changes in sexual desire or decreased sexual ability
frequent urge to urinate or increased urination
increased sweating
unpleasant taste

Although not all of the side effects listed above have been reported for all of these medicines, they have been reported for at least one of them. However, since all of the sympathomimetic appetite suppressants are similar, any of the above side effects may occur with any of these medicines.

After you stop using this medicine, your body may need time to adjust. The length of time this takes depends on the amount of medicine you were using and how long you used it. During this time check with your doctor if you notice any of the following side effects:

Extreme tiredness or weakness
mental depression
nausea or vomiting
stomach cramps or pain
trouble in sleeping or nightmares

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Last Updated: 6/12/2013

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