Phendimetrazine Tartrate

See also How to Use section.

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 are: stimulants (including amphetamines, methylphenidate, street drugs such as cocaine or MDMA/"ecstasy").

This drug should not be used with certain medications because very serious interactions may occur. If you are taking or have taken other appetite-suppressant drugs in the past year (such as 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, metaxalone, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, safinamide, 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.

Tell your doctor or pharmacist if you are taking other products that cause drowsiness such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), or antihistamines (such as cetirizine, diphenhydramine).

Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.

Some products have ingredients that could raise your heart rate or blood pressure. Tell your pharmacist what products you are using, and ask how to use them safely (especially cough-and-cold products or diet aids).

Take the immediate-release form of this medication by mouth as directed by your doctor, usually 2 to 3 times a day (1 hour before meals). Taking this medication late in the day may cause trouble sleeping (insomnia).

The sustained-release form of phendimetrazine is usually taken once a day 30 - 60 minutes before the morning meal. Swallow this medication whole. Do not crush, chew, or break the capsules. Doing so can destroy the long action of the drug and may increase side effects.

The dosage is based on your medical condition and response to treatment. 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.

Phendimetrazine 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.

Caffeine can increase the side effects of this medication. Avoid drinking large amounts of beverages containing caffeine (coffee, tea, colas), eating large amounts of chocolate, or taking nonprescription products that contain caffeine.

If you suddenly stop using this medication, you may have withdrawal symptoms (such as depression, severe tiredness). To help prevent withdrawal, your doctor may lower your dose slowly. Withdrawal is more likely if you have used phendimetrazine for a long time or in high doses. Tell your doctor or pharmacist right away if you have withdrawal.

Though it helps many people, this medication may sometimes cause addiction. This risk may be higher if you have a substance use disorder (such as overuse of or addiction to drugs/alcohol). Do not increase your dose, take it more often, 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.

Dizziness, dry mouth, difficulty sleeping, irritability, nausea, vomiting, diarrhea, or constipation may occur. If these effects last or get worse, notify your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor 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 you have any serious side effects, including: fast/irregular/pounding heartbeat, mental/mood changes (such as agitation, uncontrolled anger, hallucinations, nervousness), uncontrolled muscle movements, change in sexual ability/interest.

Get medical help right away if you have any very serious side effects, including: severe headache, trouble speaking, seizure, weakness on one side of the body, vision changes (such as 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 serious side effects, stop taking this medication and tell 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, get medical help right away if you notice any symptoms of a serious allergic reaction, including: 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/safety/medwatch-fda-safety-information-and-adverse-event-reporting-program.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

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.

Do not share this medication with others. Sharing it is against the law.

Lab and/or medical tests (such as blood pressure, heart/kidney function) may be done while you are taking this medication. Keep all medical and lab appointments. 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. Take your next dose at the regular time. Do not double the dose to catch up.

Store at room temperature away from light and moisture. Do not store in the bathroom. 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.

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 1-800-222-1222. Canada residents can call 1-844-764-7669. Symptoms of overdose may include: rapid breathing, unusual restlessness, fast/slow/irregular heartbeat, chest pain, hallucinations, seizures, loss of consciousness.