Class Name(s):

• 28:20.08.04 Amphetamine Derivatives

Pronunciation:

• (fen'' ter meen) (toe pyre' a mate)

Brand Name(s):

• Qsymia^®

WHY is this medicine prescribed?

Phentermine and topiramate is used to help adults and children aged 12 years or older who are obese, or certain adults who are overweight and have weight-related medical problems to lose weight and to keep from gaining back that weight. Phentermine and topiramate must be used along with a reduced calorie diet and exercise plan. Phentermine is in a class of medications called anorectics. It works by decreasing appetite. Topiramate is in a class of medications called anticonvulsants. It works by decreasing appetite and by causing feelings of fullness to last longer after eating.

HOW should this medicine be used?

Phentermine and topiramate come as extended-release capsules to take by mouth. The medication is usually taken with or without food once a day in the morning. This medication may cause difficulty falling asleep or staying asleep if it is taken in the evening. Take phentermine and topiramate at around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take phentermine and topiramate exactly as directed.

Your doctor will probably start you on a low dose of phentermine and topiramate and increase your dose after 14 days. After you take this dose for 12 weeks, your doctor will check to see how much weight you have lost. If you have not lost a certain amount of weight, your doctor may tell you to stop taking phentermine and topiramate or may increase your dose and then increase it again after 14 days. After you take the new dose for 12 weeks, your doctor will check to see how much weight you have lost. If you have not lost a certain amount of weight, it is not likely that you will benefit from taking phentermine and topiramate, so your doctor will probably tell you to stop taking the medication.

Phentermine and topiramate may be habit forming. Do not take a larger dose, take it more often, or take it for a longer period of time than prescribed by your doctor.

Phentermine and topiramate will help control your weight only as long as you continue to take the medication. Do not stop taking phentermine and topiramate without talking to your doctor. If you suddenly stop taking phentermine and topiramate, you may experience seizures. Your doctor will tell you how to decrease your dose gradually.

Because of the risk of birth defects, phentermine and topiramate is available only through a special restricted distribution program. A program called the Qsymia REMS (Risk Evaluation and Mitigation Strategy) Program has been set up to decrease the risks of taking phentermine and topiramate. You can only receive the medication from a pharmacy that participates in the program. Ask your doctor if you have any questions about participating in the program or how to get your medication.

Your doctor or pharmacist will give you the manufacturer's patient information sheet (Medication Guide) when you begin treatment with phentermine and topiramate and each time you refill your prescription. Read the information carefully and ask your doctor or pharmacist if you have any questions. You can also visit the Food and Drug Administration (FDA) website (http://www.fda.gov/Drugs/DrugSafety/ucm085729.htm) or the manufacturer's website to obtain the Medication Guide.

Are there OTHER USES for this medication?

This medication may be prescribed for other uses; ask your doctor or pharmacist for more information.

What SPECIAL PRECAUTIONS should I follow?

Before taking phentermine and topiramate,

• tell your doctor and pharmacist if you are allergic to phentermine (Adipex-P, Lomaira); topiramate (Eprontia, Qudexy XR, Topamax, Trokendi XR); sympathomimetic amine medications such as midodrine (Orvaten) or phenylephrine (in cough and cold medications); aspirin; tartrazine (a yellow dye in some processed foods and drugs); any other medications, or any of the ingredients in phentermine and topiramate capsules. Ask your pharmacist or check the Medication Guide for a list of the ingredients.
• tell your doctor if you are taking the following medications or have stopped taking them within the past two weeks: monoamine oxidase inhibitors (MAOI) including isocarboxazid (Marplan), phenelzine (Nardil), selegiline (Eldepryl, Emsam, Zelapar), and tranylcypromine (Parnate).. Your doctor will probably tell you not to take phentermine and topiramate if you are taking one or more of these medications or have taken one of these medications during the past 2 weeks.
• tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
• tell your doctor if you have glaucoma (condition in which increased pressure in the eye can cause vision loss) or an overactive thyroid gland. Your doctor will probably tell you not to take phentermine and topiramate.
• tell your doctor if you have had a heart attack or a stroke in the past 6 months, if you have ever thought about killing yourself or tried to do so, and if you are following a ketogenic diet (high fat, low carbohydrate diet used to control seizures). Also tell your doctor if you have or have ever had depression or abnormal moods; an irregular heartbeat; heart failure; seizures; metabolic acidosis (too much acid in the blood); low levels of potassium in your blood; osteopenia, osteomalacia, or osteoporosis (conditions in which the bones are brittle or weak and may break easily); ongoing diarrhea; any condition that affects your breathing; diabetes; kidney stones; or kidney or liver disease.
• tell your doctor if you are pregnant or plan to become pregnant. If you take phentermine and topiramate during pregnancy, your baby may develop a birth defect called cleft lip or cleft palate and your baby may be smaller than expected at birth. Your baby may develop this birth defect very early in the pregnancy, before you know that you are pregnant. You must use birth control to prevent pregnancy during your treatment. You must take a pregnancy test before you begin your treatment and once every month during your treatment. If you become pregnant while taking phentermine and topiramate, stop taking the medication and call your doctor immediately.
• you can use oral contraceptives (birth control pills) to prevent pregnancy during your treatment with phentermine and topiramate. You may experience unusual spotting (unexpected vaginal bleeding) if you use this type of birth control. You will still be protected from pregnancy if you are spotting, but you can talk to your doctor about other forms of birth control if the spotting is bothersome.
• Lactation: tell your doctor if you are breast-feeding.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking phentermine and topiramate.
• you should know that phentermine and topiramate may slow your thinking and movements and affect your vision. Do not drive a car or operate machinery until you know how this medication affects you.
• do not drink alcoholic beverages while you are taking phentermine and topiramate. Alcohol can make the side effects of phentermine and topiramate worse.
• you should know that phentermine and topiramate can prevent you from sweating and make it harder for your body to cool down when it gets very hot. Avoid exposure to heat, drink plenty of fluids and tell your doctor if you have a fever, headache, muscle cramps, or an upset stomach, or if you are not sweating as usual.
• you should know that your mental health may change in unexpected ways and you may become suicidal (thinking about harming or killing yourself or planning or trying to do so) while you are taking phentermine and topiramate. A small number of adults and children 5 years of age and older (about 1 in 500 people) who took antiepileptics such as topiramate to treat various conditions during clinical studies became suicidal during their treatment. Some of these people developed suicidal thoughts and behavior as early as 1 week after they started taking the medication. You, your family, or your caregiver should call your doctor right away if you experience any of the following symptoms: panic attacks; agitation or restlessness; new or worsening irritability, anxiety, or depression; acting on dangerous impulses; difficulty falling or staying asleep; aggressive, angry, or violent behavior; mania (frenzied, abnormally excited mood); talking or thinking about wanting to hurt yourself or end your life; withdrawing from friends and family; preoccupation with death and dying; giving away prized possessions; or any other unusual changes in behavior or mood. Be sure that your family or caregiver knows which symptoms may be serious so they can call the doctor if you are unable to seek treatment on your own.
• You should know that phentermine and topiramate may slow the increase in height in children 12 years of age and older if used for a long period of time.

What SPECIAL DIETARY instructions should I follow?

Drink extra fluids during your treatment with phentermine and topiramate.

Unless your doctor tells you otherwise, continue your normal diet.

What should I do IF I FORGET to take a dose?

Skip the missed dose and take your usual dose the next morning. Do not take a double dose to make up for a missed one.

What SIDE EFFECTS can this medicine cause?

Phentermine and topiramate may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• headache
• dizziness
• numbness, burning, or tingling in the hands, feet, face, or mouth
• difficulty falling or staying asleep
• decreased sense of touch or ability to feel sensation
• difficulty concentrating, thinking, paying attention, speaking, or remembering
• excessive tiredness
• dry mouth
• unusual thirst
• changes or decreased ability to taste food
• nausea
• diarrhea
• constipation
• heartburn
• painful menstrual periods
• pain in the back, neck, muscles, arms or legs
• tightening of the muscles
• painful, difficult, or frequent urination
• hair loss
• fever, sore throat, cough, congestion, or other signs of infection

Some side effects can be serious. If you experience any of these symptoms or those listed in the SPECIAL PRECAUTIONS section, call your doctor immediately or get emergency medical treatment:

• racing or pounding heartbeat that lasts several minutes
• sudden decrease in vision
• eye pain or redness
• fast, shallow breathing
• severe pain in the pack or side
• blood in urine
• rash, hives, peeling, or blistering skin

Phentermine and topiramate may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

What should I do in case of OVERDOSE?

In case of overdose, call the poison control helpline at 1-800-222-1222. Information is also available online at http://www.poisonhelp.org/help. If the victim has collapsed, had a seizure, has trouble breathing, or can't be awakened, immediately call emergency services at 911.

Symptoms of overdose may include the following:

• restlessness
• uncontrollable shaking of a part of the body
• fast breathing
• confusion
• aggressiveness
• hallucinations (seeing things or hearing voices that do not exist)
• panic
• excessive tiredness
• depression
• irregular heartbeat
• nausea
• vomiting
• diarrhea
• stomach pain or cramps
• seizures
• coma (loss of consciousness for a period of time)
• dizziness
• drowsiness
• speech disturbances
• blurred or double vision
• problems with coordination
• fast, shallow breathing

What should I know about STORAGE and DISPOSAL of this medication?

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

Store phentermine and topiramate in a safe place so that no one else can take it accidentally or on purpose. Keep track of how many capsules are left so you will know if any are missing.

Dispose of unneeded medications in a way so that pets, children, and other people cannot take them. Do not flush this medication down the toilet. Use a medicine take-back program. Talk to your pharmacist about take-back programs in your community. Visit the FDA's Safe Disposal of Medicines website http://goo.gl/c4Rm4p for more information.

Keep all medication out of sight and reach of children as many containers are not child-resistant. Always lock safety caps. Place the medication in a safe location - one that is up and away and out of their sight and reach. http://www.upandaway.org

What OTHER INFORMATION should I know?

Keep all appointments with your doctor and the laboratory. Your doctor will order certain lab tests to check your body's response to phentermine and topiramate.

Do not let anyone else take your medication. Giving or selling phentermine and topiramate to others may harm them and is against the law. Phentermine and topiramate is a controlled substance. Prescriptions may be refilled only a limited number of times; ask your pharmacist if you have any questions.

Keep a written list of all of the prescription and nonprescription (over-the-counter) medicines, vitamins, minerals, and dietary supplements you are taking. Bring this list with you each time you visit a doctor or if you are admitted to the hospital. You should carry the list with you in case of emergencies.

This report on medications is for your information only, and is not considered individual patient advice. Because of the changing nature of drug information, please consult your physician or pharmacist about specific clinical use.

The American Society of Health-System Pharmacists, Inc. represents that the information provided hereunder was formulated with a reasonable standard of care, and in conformity with professional standards in the field. The American Society of Health-System Pharmacists, Inc. makes no representations or warranties, express or implied, including, but not limited to, any implied warranty of merchantability and/or fitness for a particular purpose, with respect to such information and specifically disclaims all such warranties. Users are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the information is provided for informational purposes only. The entire monograph for a drug should be reviewed for a thorough understanding of the drug's actions, uses and side effects. The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug. The information is not a substitute for medical care.

AHFS^® Patient Medication Information™ Copyright, 2025. The American Society of Health-System Pharmacists^®, 4500 East-West Highway, Suite 900, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.

Selected Revisions: September 15, 2023.