Benzphetamine is used short-term along with a doctor-approved, reduced-calorie diet, exercise, and behavior change program to help you lose weight. It is used in people who are significantly overweight (obese) and have not been able to lose enough weight with diet and exercise alone. Losing weight and keeping it off can reduce the many health risks that come with obesity, including heart disease, diabetes, high blood pressure, and a shorter life.
It is not known how this medication helps people to lose weight. It may work by decreasing your appetite, increasing the amount of energy used by your body, or by affecting certain parts of the brain. This medication is an appetite suppressant and belongs to a class of drugs called sympathomimetic amines.
The dosage is based on your medical condition and response to therapy. Your doctor will adjust the dose to find the best dose for you. Use this medication regularly and exactly as prescribed in order to get the most benefit from it. To help you remember, take it at the same time(s) each day.
Benzphetamine is usually taken for only a few weeks at a time. It should not be taken with other appetite suppressants (see also Drug Interactions section). The possibility of serious side effects increases with longer use of this medication and use of this drug along with certain other diet drugs.
This medication may cause withdrawal reactions, especially if it has been used regularly for a long time or in high doses. In such cases, withdrawal symptoms (such as depression, severe tiredness) may occur if you suddenly stop using this medication. To prevent withdrawal reactions, your doctor may reduce your dose gradually. Consult your doctor or pharmacist for more details, and report any withdrawal reactions right away.
Rarely, abnormal drug-seeking behavior (addiction) is possible with this medication. Do not increase your dose, take it more frequently, or use it for a longer time than prescribed. Properly stop the medication when so directed.
This medication may stop working well after you have been taking it for a while. Talk with your doctor if this medication stops working well. Do not increase the dose unless directed by your doctor. Your doctor may direct you to stop taking this medication.
Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.
This medication may raise your blood pressure. Check your blood pressure regularly and tell your doctor if the results are high.
Tell your doctor right away if any of these unlikely but serious side effects occur: fast/irregular/pounding heartbeat, mental/mood changes (e.g., agitation, uncontrolled anger, hallucinations, nervousness), uncontrolled muscle movements, change in sexual ability/interest.
Stop taking this medication and seek immediate medical attention if any of these rare but very serious side effects occur: severe headache, slurred speech, seizure, weakness on one side of the body, vision changes (e.g., blurred vision).
This drug may rarely cause serious (sometimes fatal) lung or heart problems (pulmonary hypertension, heart valve problems). The risk increases with longer use of this medication and use of this drug along with other appetite-suppressant drugs/herbal products. If you notice any of the following unlikely but very serious side effects, stop taking this medication and consult your doctor or pharmacist right away: chest pain, difficulty breathing with exercise, decreased ability to exercise, fainting, swelling of the legs/ankles/feet.
A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any of the following symptoms of a serious allergic reaction: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.
In the US -
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
Before taking benzphetamine, tell your doctor or pharmacist if you are allergic to it; or to any other sympathomimetic amines (e.g., decongestants such as pseudoephedrine, stimulants such as amphetamine, appetite suppressants such as phentermine); or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of: heart disease (e.g., chest pain, heart attack, heart murmur, fast/irregular heartbeat, heart valve problems), high blood pressure, glaucoma, history of alcohol/drug abuse, mental/mood problems (e.g., severe anxiety, bipolar disorder, psychosis, schizophrenia), high blood pressure in the lungs (pulmonary hypertension), stroke, overactive thyroid (hyperthyroidism), diabetes, kidney disease, seizures.
This drug may make you dizzy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Avoid alcoholic beverages.
If you have diabetes, check your blood sugar levels regularly as directed by your doctor. Your doctor may need to adjust your diabetes medication during treatment with this drug.
Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).
Kidney function declines as you grow older. This medication is removed by the kidneys. Therefore, elderly people may be at greater risk for dizziness and high blood pressure while using this drug.
Benzphetamine must not be used during pregnancy. It may harm an unborn baby. If you become pregnant or think you may be pregnant, inform your doctor right away. Infants born to mothers who have been using this medication for a long time or in high doses may have withdrawal symptoms such as irritability or extreme tiredness. Tell your doctor right away if you notice any of these symptoms in your newborn.
This drug may pass into breast milk and could have undesirable effects on a nursing infant. Therefore, breast-feeding is not recommended while using this drug. Consult your doctor before breast-feeding.
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.
Some products that may interact with this drug include: drugs for depression (e.g., TCAs such as imipramine, SSRIs and SNRIs such as paroxetine, fluoxetine, venlafaxine, duloxetine), phenothiazines (e.g., prochlorperazine, chlorpromazine), other stimulants (e.g., amphetamines, methylphenidate, street drugs such as cocaine or MDMA/"ecstasy").
If you are taking or have taken other appetite-suppressant drugs in the past year (e.g., phentermine, ephedra/ma huang), tell your doctor or pharmacist before starting this medication.
Taking MAO inhibitors with this medication may cause a serious (possibly fatal) drug interaction. Avoid taking MAO inhibitors (isocarboxazid, linezolid, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, selegiline, tranylcypromine) during treatment with this medication. Most MAO inhibitors should also not be taken for two weeks before treatment with this medication. Ask your doctor when to start or stop taking this medication.
Check the labels on all your medicines/herbal products (e.g., cough-and-cold products containing decongestants such as pseudoephedrine, diet aids such as phenylpropanolamine, ephedra/ma huang) because they may contain ingredients that could increase your heart rate or blood pressure. Ask your pharmacist about using those products safely.
Caffeine can increase the side effects of this medication. Avoid drinking large amounts of beverages containing caffeine (coffee, tea, colas) or eating large amounts of chocolate.
If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: rapid breathing, unusual restlessness, fast/slow/irregular heartbeat, chest pain, hallucinations, seizures, loss of consciousness.
Do not share this medication with others. It is against the law.
Appetite suppressants should not be used in place of proper diet. For best results, this drug must be used along with a doctor-approved diet and exercise program.
Laboratory and/or medical tests (e.g., blood pressure, heart tests, kidney tests) may be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.
If you miss a dose, take it as soon as you remember. If it is near the time of the next dose or late in the evening, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.
Store at room temperature away from light and moisture. Keep all medications away from children and pets.
Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
Information last revised July 2016. Copyright(c) 2016 First Databank, Inc.
With WebMD's Medicine Cabinet, you can check interactions with drugs.Go to medicine cabinet