Phendimetrazine (By mouth)
Phendimetrazine (fen-dye-MET-ra-zeen)
Helps with weight loss in patients with obesity. This medicine is an appetite suppressant.
Brand Name(s):
Bontril Slow-Release
There may be other brand names for this medicine.When This Medicine Should Not Be Used:
This medicine is not right for everyone. Do not use it if you had an allergic reaction to phendimetrazine, or if you also use any other stimulant or diet pill. Do not use this medicine if you are feeling agitated, or if you have glaucoma, overactive thyroid, or a history of heart and blood vessel disease (including uncontrolled high blood pressure, arrhythmia, clogged arteries, heart failure, pulmonary hypertension, or stroke), or drug use disorder. Do not use this medicine if you are pregnant or breastfeeding.How to Use This Medicine:
Capsule, Long Acting Capsule, Tablet
- Your doctor will tell you how much medicine to use. Do not use more than directed. Carefully follow your doctor's instructions for a reduced-calorie diet plan and regular exercise.
- Take the tablet 1 hour before a meal. Take the capsule 30 to 60 minutes before a meal.
- Swallow the capsule whole. Do not break, crush, or chew it.
- Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.
- Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.
Drugs and Foods to Avoid:
Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.
- Do not use this medicine if you are taking or have taken other medicines that reduce appetite within the past year (including dexfenfluramine, fenfluramine).
- Do not use this medicine if you are using or have used an MAO inhibitor within the past 14 days.
- Some medicines and foods can affect how phendimetrazine works. Tell your doctor if you are also using guanethidine, sibutramine, or insulin or diabetes medicine.
Warnings While Using This Medicine:
- It is not safe to take this medicine during pregnancy. It could harm an unborn baby. Tell your doctor right away if you become pregnant.
- Tell your doctor if you have kidney disease, diabetes, heart valve disease, or high blood pressure.
- This medicine may cause the following problems:
- Increased risk of pulmonary hypertension (increased blood pressure in the lungs)
- Heart or blood vessel problem, including valvular heart disease
- This medicine may cause some people to become dizzy, lightheaded, or less alert than they are normally. Do not drive or do anything that could be dangerous until you know how this medicine affects you.
- This medicine can be habit-forming. Do not use more than your prescribed dose. Call your doctor if you think your medicine is not working.
- Do not stop using this medicine suddenly. Your doctor will need to slowly decrease your dose before you stop it completely.
- Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.
- Keep all medicine out of the reach of children. Never share your medicine with anyone.
Possible Side Effects While Using This Medicine:
Call your doctor right away if you notice any of these side effects:
- Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
- Change in how much or how often you urinate
- Chest pain, trouble breathing
- Confusion, feelings of panic, or seeing, hearing, or feeling things that are not there
- Fainting, swelling of your feet or lower legs
- Fast, pounding, or uneven heartbeat
If you notice these less serious side effects, talk with your doctor:
- Dry mouth, constipation, diarrhea, nausea, stomach pain
- Feeling restless, excited, agitated
- Headache, blurred vision
- Increased or decreased interest in sex
- Sweating
- Tremors or shaking
- Warmth or redness in your face, neck, arms, or upper chest
If you notice other side effects that you think are caused by this medicine, tell your doctor
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088
Last Updated: 9/6/2024
