Phendimetrazine is used with a doctor-approved exercise, behavior change, and reduced-calorie diet program to help you lose weight. It is used by certain overweight people, such as those who are obese or have weight-related medical problems. Losing weight and keeping it off can lessen 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.
Take the immediate-release form of this medication by mouth, usually 2 to 3 times a day 1 hour before meals or as directed by your doctor. Taking this medication late in the day may cause trouble sleeping (insomnia). 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 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. 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.
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.
Dizziness, dry mouth, difficulty sleeping, irritability, nausea, vomiting, diarrhea, or constipation may occur. If these effects persist or worsen, notify your doctor or pharmacist promptly. 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.
Before taking phendimetrazine, tell your doctor or pharmacist if you are allergic to it; or to any other sympathomimetic amines (including 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: diabetes, high blood pressure, glaucoma, heart problems (such as chest pain, heart attack, heart murmur, fast/irregular heartbeat, heart valve problems), mental/mood problems (such as severe anxiety/agitation, depression, psychosis, schizophrenia), high blood pressure in the lungs (pulmonary hypertension), kidney disease, seizure problem, stroke, overactive thyroid (hyperthyroidism), personal or family history of a substance use disorder (such as overuse of or addiction to drugs/alcohol). This drug may make you dizzy or blur your vision.
It may also rarely make you drowsy. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness or clear vision until you can do it safely. Avoid alcoholic beverages.
Store the slow-release form of this medication at room temperature between 68-77 degrees F (20-25 degrees C) away from light and moisture. Store the immediate-release form of this medication at room temperature at 77 degrees F (25 degrees C) away from light and moisture. Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.