Phentermine and Topiramate

Adult Medication
Share

This information from Lexicomp® explains what you need to know about this medication, including what it’s used for, how to take it, its side effects, and when to call your healthcare provider.

Brand Names: US

Qsymia

What is this drug used for?

  • It is used to help with weight loss in certain people.

What do I need to tell my doctor BEFORE I take this drug?

  • If you are allergic to this drug; any part of this drug; or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
  • If you have any of these health problems: Glaucoma or overactive thyroid disease.
  • If you have or have ever had depression or thoughts of suicide.
  • 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 for depression or Parkinson’s disease in the last 14 days. This includes isocarboxazid, phenelzine, tranylcypromine, selegiline, or rasagiline. Very high blood pressure may happen.
  • If you are taking any of these drugs: Linezolid or methylene blue.
  • If you are pregnant or may be pregnant. Do not take this drug if you are pregnant.
  • If you are breast-feeding. Do not breast-feed while you take this drug.
  • If the patient is a child younger than 12 years of age. This drug is not approved for use in children younger than 12 years of age.

This is not a list of all drugs or health problems that interact with this drug.

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 this drug 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 this drug?

  • Tell all of your health care providers that you take this drug. 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 this drug affects you.
  • Have blood work, blood pressure, and heart rate checked as you have been told by the doctor.
  • Follow the diet and exercise plan that your doctor told you about.
  • Do not stop taking this drug 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.
  • Talk with your doctor before you use alcohol, marijuana or other forms of cannabis, or prescription or OTC drugs that may 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 drug may cause an acid blood problem (metabolic acidosis). The chance may be higher in children and in people with kidney problems, breathing problems, or 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.
  • If you are allergic to tartrazine (FD&C Yellow No. 5), talk with your doctor. Some products have tartrazine.
  • Sweating less and high body temperatures have happened with this drug. 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.
  • This drug may affect growth in children and teens in some cases. They may need regular growth checks. Talk with the doctor.
  • If you take birth control, your monthly period (menstrual bleeding) may change while taking this drug. Talk with your doctor if this happens.
  • A pregnancy test will be done to show that you are NOT pregnant before starting this drug and while taking it.
  • The risk of birth defects is higher if this drug is taken during pregnancy. The baby may also be smaller at birth. It is not known if this leads to long-term problems. If you may become pregnant, you must use birth control while taking this drug. If you get pregnant, call your doctor right away.

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.
  • Fast or abnormal heartbeat.
  • Feeling confused, not able to focus, or change in behavior.
  • Memory problems or loss.
  • Trouble speaking.
  • Trouble sleeping.
  • Not able to pass urine or change in how much urine is passed.
  • Back pain, belly pain, or blood in the urine. May be signs of a kidney stone.
  • Patients who take this drug 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 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 drug 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.
  • A severe skin reaction (Stevens-Johnson syndrome/toxic epidermal necrolysis) may happen. It can cause severe health problems that may not go away, and sometimes death. Get medical help right away if you have signs like red, swollen, blistered, or peeling skin (with or without fever); red or irritated eyes; or sores in your mouth, throat, nose, or eyes.

What are some other side effects of this drug?

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:

  • Headache.
  • Diarrhea or constipation.
  • Dry mouth.
  • Numbness or tingling.
  • Feeling dizzy, tired, or weak.
  • Change in taste.
  • Upset stomach.
  • Signs of a common cold.
  • Nose or throat irritation.
  • Back pain.
  • Joint 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 your national health agency.

You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.

How is this drug best taken?

Use this drug as ordered by your doctor. Read all information given to you. Follow all instructions closely.

  • Take with or without food.
  • To prevent sleep problems, avoid taking this drug late in the day.
  • 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.

How do I store and/or throw out this drug?

  • Store at room temperature in a dry place. Do not store in a bathroom.
  • Keep lid tightly closed.
  • Store this drug in a safe place where children cannot see or reach it, and where other people cannot get to it. A locked box or area may help keep this drug safe. Keep all drugs away from 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.

General drug facts

  • 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.
  • Some drugs may have another patient information leaflet. If you have any questions about this drug, please talk with your doctor, nurse, pharmacist, or other health care provider.
  • This drug comes with an extra patient fact sheet called a Medication Guide. Read it with care. Read it again each time this drug is refilled. If you have any questions about this drug, please talk with the doctor, pharmacist, or other health care provider.
  • 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.

Consumer Information Use and Disclaimer

This generalized information is a limited summary of diagnosis, treatment, and/or medication information. It is not meant to be comprehensive and should be used as a tool to help the user understand and/or assess potential diagnostic and treatment options. It does NOT include all information about conditions, treatments, medications, side effects, or risks that may apply to a specific patient. It is not intended to be medical advice or a substitute for the medical advice, diagnosis, or treatment of a health care provider based on the health care provider’s examination and assessment of a patient’s specific and unique circumstances. Patients must speak with a health care provider for complete information about their health, medical questions, and treatment options, including any risks or benefits regarding use of medications. This information does not endorse any treatments or medications as safe, effective, or approved for treating a specific patient. UpToDate, Inc. and its affiliates disclaim any warranty or liability relating to this information or the use thereof. The use of this information is governed by the Terms of Use, available at https://www.wolterskluwer.com/en/know/clinical-effectiveness-terms.

Last Reviewed Date

2024-12-09

Copyright

© 2024 UpToDate, Inc. and its affiliates and/or licensors. All rights reserved.

Last Updated

Monday, December 12, 2022