Phentermine and Topiramate
Generic Name: Phentermine and Topiramate (FEN ter meen & toe PYRE a mate)
Brand Name: Qsymia
Medically reviewed on Sep 5, 2018
Uses of Phentermine and Topiramate:
- It is used to help you lose weight.
What do I need to tell my doctor BEFORE I take Phentermine and Topiramate?
For all patients taking phentermine and topiramate:
- If you have an allergy to phentermine, topiramate or any other part of phentermine and topiramate.
- If you are allergic to any drugs like this one, any other drugs, foods, or other substances. Tell your doctor about the allergy and what signs you had, like rash; hives; itching; shortness of breath; wheezing; cough; swelling of face, lips, tongue, or throat; or any other signs.
- If you have any of these health problems: Glaucoma or overactive thyroid disease.
- If you have or have ever had low mood (depression) or thoughts of killing yourself.
- If you have any of these health problems: Kidney disease or liver disease.
- If you are taking any of these drugs: Acetazolamide, dichlorphenamide, methazolamide, or zonisamide.
- If you have taken certain drugs used for low mood (depression) like isocarboxazid, phenelzine, or tranylcypromine or drugs used for Parkinson's disease like selegiline or rasagiline in the last 14 days. Taking phentermine and topiramate within 14 days of those drugs can cause very bad high blood pressure.
- If you are pregnant or may be pregnant. Do not take phentermine and topiramate if you are pregnant.
- If you are breast-feeding or plan to breast-feed.
- If the patient is a child. Do not give phentermine and topiramate to a child.
This is not a list of all drugs or health problems that interact with phentermine and topiramate.
Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take phentermine and topiramate with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.
What are some things I need to know or do while I take Phentermine and Topiramate?
- Tell all of your health care providers that you take phentermine and topiramate. This includes your doctors, nurses, pharmacists, and dentists.
- Avoid driving and doing other tasks or actions that call for you to be alert until you see how phentermine and topiramate affects you.
- Do not stop taking phentermine and topiramate all of a sudden without calling your doctor. You may have a greater risk of seizures. If you need to stop this drug, you will want to slowly stop it as ordered by your doctor.
- Check blood pressure and heart rate as the doctor has told you. Talk with the doctor.
- Have blood work checked as you have been told by the doctor. Talk with the doctor.
- Avoid drinking alcohol while taking phentermine and topiramate.
- Talk with your doctor before you use other drugs and natural products that slow your actions.
- If you have high blood sugar (diabetes) and take drugs to lower blood sugar, talk with your doctor. Weight loss may raise the chance of low blood sugar if you take drugs to lower blood sugar. Call your doctor right away if you have signs of low blood sugar like dizziness, headache, feeling sleepy, feeling weak, shaking, a fast heartbeat, confusion, hunger, or sweating.
- If you are being treated for high blood pressure, talk with your doctor. Weight loss may raise the chance of low blood pressure in people who are treated for high blood pressure. Call your doctor right away if you have signs of low blood pressure like very bad dizziness or passing out.
- This medicine may cause an acid blood problem (metabolic acidosis). The chance may be higher in children and in people with kidney problems, breathing problems, or loose stools (diarrhea). The chance may also be higher if you take certain other drugs, if you have surgery, or if you are on a ketogenic diet. Over time, metabolic acidosis can cause kidney stones, bone problems, or growth problems in children. Talk with your doctor.
- Follow the diet and workout plan that your doctor told you about.
- Sweating less and high body temperatures have happened with phentermine and topiramate. Sometimes, this has led to the need for treatment in a hospital. Be careful in hot weather and while being active. Call your doctor right away if you have a fever or you do not sweat during activities or in warm temperatures.
- If you take birth control, your monthly period (menstrual bleeding) may change while taking phentermine and topiramate. Talk with your doctor if this happens.
- This medicine may cause harm to the unborn baby if you take it while you are pregnant.
- If you are able to get pregnant, a pregnancy test will be done to show that you are NOT pregnant before starting phentermine and topiramate. Talk with your doctor.
- A pregnancy test will be done every month during care.
- Use birth control that you can trust to prevent pregnancy while taking phentermine and topiramate.
- If you are pregnant or you get pregnant while taking phentermine and topiramate, call your doctor right away.
How is this medicine (Phentermine and Topiramate) best taken?
Use phentermine and topiramate as ordered by your doctor. Read all information given to you. Follow all instructions closely.
- Take phentermine and topiramate early in the day to prevent sleep problems.
- Take with or without food.
- Drink lots of noncaffeine liquids unless told to drink less liquid by your doctor.
What do I do if I miss a dose?
- Skip the missed dose and go back to your normal time.
- Do not take 2 doses at the same time or extra doses.
See also: Dosage Information (in more detail)
What are some side effects that I need to call my doctor about right away?
WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:
- Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
- Signs of too much acid in the blood (acidosis) like confusion; fast breathing; fast heartbeat; a heartbeat that does not feel normal; very bad stomach pain, upset stomach, or throwing up; feeling very sleepy; shortness of breath; or feeling very tired or weak.
- Signs of low potassium levels like muscle pain or weakness, muscle cramps, or a heartbeat that does not feel normal.
- Signs of a urinary tract infection (UTI) like blood in the urine, burning or pain when passing urine, feeling the need to pass urine often or right away, fever, lower stomach pain, or pelvic pain.
- Feeling confused.
- Chest pain or pressure or a fast heartbeat.
- Not able to focus.
- Memory problems or loss.
- Trouble speaking.
- Not able to sleep.
- Back pain, belly pain, or blood in the urine. May be signs of a kidney stone.
- Patients who take phentermine and topiramate may be at a greater risk of having thoughts or actions of suicide. The risk may be greater in people who have had these thoughts or actions in the past. Call the doctor right away if signs like low mood (depression), nervousness, restlessness, grouchiness, panic attacks, or changes in mood or actions are new or worse. Call the doctor right away if any thoughts or actions of suicide occur.
- This medicine may cause very bad eye problems. If left untreated, this can lead to lasting eyesight loss. Call your doctor right away if you have new eye signs like blurred eyesight or other changes in eyesight, eye pain, or eye redness.
What are some other side effects of Phentermine and Topiramate?
All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:
- Hard stools (constipation).
- Dry mouth.
- Numbness and tingling.
- Change in taste.
- Upset stomach.
- Loose stools (diarrhea).
- Feeling tired or weak.
- Nose or throat irritation.
- Back pain.
These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.
You may report side effects to the FDA at 1-800-FDA-1088. You may also report side effects at http://www.fda.gov/medwatch.
See also: Side effects (in more detail)
If OVERDOSE is suspected:
If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.
How do I store and/or throw out Phentermine and Topiramate?
- Store at room temperature.
- Keep lid tightly closed.
- Store in a dry place. Do not store in a bathroom.
- Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
- Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.
Consumer information use
- If your symptoms or health problems do not get better or if they become worse, call your doctor.
- Do not share your drugs with others and do not take anyone else's drugs.
- Keep a list of all your drugs (prescription, natural products, vitamins, OTC) with you. Give this list to your doctor.
- Talk with the doctor before starting any new drug, including prescription or OTC, natural products, or vitamins.
- This medicine comes with an extra patient fact sheet called a Medication Guide. Read it with care. Read it again each time phentermine and topiramate is refilled. If you have any questions about phentermine and topiramate, please talk with the doctor, pharmacist, or other health care provider.
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
More about phentermine/topiramate
- Phentermine/topiramate Side Effects
- During Pregnancy
- Dosage Information
- Drug Interactions
- Support Group
- En Español
- 579 Reviews
- Drug class: anorexiants
Other brands: Qsymia