Fosamprenavir

WHY is this medicine prescribed?

Fosamprenavir is used along with other medications to treat human immunodeficiency virus (HIV) infection. Fosamprenavir is in a class of medications called protease inhibitors. It works by decreasing the amount of HIV in the blood. Although fosamprenavir does not cure HIV, it may decrease your chance of developing acquired immunodeficiency syndrome (AIDS) and HIV-related illnesses such as serious infections or cancer. Taking these medications along with practicing safer sex and making other life-style changes may decrease the risk of transmitting the HIV virus to other people.

HOW should this medicine be used?

Fosamprenavir comes as a tablet and a suspension (liquid) to take by mouth. It is usually taken once or twice a day. The tablets can be taken with or without food. In patients at least 18 years old, the suspension should be taken without food. In patients younger than 18 years old, the suspension should be taken with food. To help you remember to take fosamprenavir, take it around the same time(s) 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 fosamprenavir exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

If you are taking the suspension, shake it well before each use to mix the medication evenly.

If you vomit less than 30 minutes after you take fosamprenavir, you should take another full dose of fosamprenavir.

Fosamprenavir controls HIV infection but does not cure it. Continue to take fosamprenavir even if you feel well. Do not stop taking fosamprenavir without talking to your doctor. If you miss doses or stop taking fosamprenavir, your condition may become more difficult to treat.

Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient.

Are there OTHER USES for this medicine?

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

What SPECIAL PRECAUTIONS should I follow?

Before taking fosamprenavir,

• tell your doctor and pharmacist if you are allergic to fosamprenavir, amprenavir (Agenerase; no longer available in the U.S.), sulfa medications, any other medications, or any of the ingredients in fosamprenavir tablets or suspension. Ask your pharmacist for a list of the ingredients.
• tell your doctor if you are taking alfuzosin (Uroxatral); cisapride (Propulsid) (not available in the US); delavirdine (Rescriptor); ergot medications such as dihydroergotamine (D.H.E. 45, Migranal), ergoloid mesylates (Hydergine), ergonovine, ergotamine (Ergomar, in Cafergot, in Migergot), and methylergonovine (Methergine); lomitapide (Juxtapid); lovastatin (Altoprev); midazolam (Versed); pimozide (Orap); rifampin (Rifadin, Rimactane, in Rifater, in Rifamate); sildenafil (only Revatio brand used for lung disease); simvastatin (Zocor, in Vytorin); St. John's wort; or triazolam (Halcion). Your doctor will probably tell you not to take fosamprenavir if you are taking one or more of these medications.
• do not take flecainide, lurasidone (Latuda), or propafenone (Rhythmol) if you are taking fosamprenavir and ritonavir (Norvir) together.
• some medications should not be taken with fosamprenavir. Other medications may cause dosing changes or extra monitoring when taken with fosamprenavir. Make sure you have discussed any medications you are currently taking or plan to take before starting fosamprenavir with your doctor and pharmacist. Before starting, stopping, or changing any medications while taking fosamprenavir, please get the advice of your doctor or pharmacist.
• you should know that fosamprenavir may decrease the effectiveness of hormonal contraceptives (birth control pills, patches, rings, and injections). You will need to use another method of contraception to prevent pregnancy while taking fosamprenavir. Talk to your doctor about other ways to prevent pregnancy while you are taking this medication.
• the following nonprescription or herbal products may interact with fosamprenavir: St. John's wort; antacids; H2-receptor antagonists such as cimetidine, famotidine, nizatidine, ranitidine. Be sure to let your doctor and pharmacist know that you are taking these medications before you start taking fosmaprenavir. Do not start any of these medications while taking fosamprenavir without discussing with your healthcare provider.
• you should know that fosamprenavir may decrease the effectiveness of oral contraceptives (birth control pills). Talk to your doctor about other ways to prevent pregnancy while you are taking this medication.
• tell your doctor if you have or have ever had diabetes, hemophilia (a disease in which the blood does not clot normally), high cholesterol or triglycerides, or kidney or liver disease, including hepatitis B or C.
• tell your doctor if you are pregnant or plan to become pregnant. If you become pregnant while taking fosamprenavir, call your doctor. You should not breast-feed if you are infected with HIV or are taking fosamprenavir.
• if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking fosamprenavir.
• you should know that your body fat may increase or move to different areas of your body such as your breasts and upper back.
• you should know that you may experience hyperglycemia (increases in your blood sugar) while you are taking this medication, even if you do not already have diabetes. Tell your doctor immediately if you have any of the following symptoms while you are taking fosamprenavir: extreme thirst, frequent urination, extreme hunger, blurred vision, or weakness. It is very important to call your doctor as soon as you have any of these symptoms, because high blood sugar that is not treated can cause a serious condition called ketoacidosis. Ketoacidosis may become life-threatening if it is not treated at an early stage. Symptoms of ketoacidosis include: dry mouth, nausea and vomiting, shortness of breath, breath that smells fruity, and decreased consciousness.
• you should know that while you are taking medications to treat HIV infection, your immune system may get stronger and begin to fight other infections that were already in your body. This may cause you to develop symptoms of those infections. If you have new or worsening symptoms at anytime during your treatment with fosamprenavir, be sure to tell your doctor.

What SPECIAL DIETARY instructions should I follow?

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

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

Take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.

What SIDE EFFECTS can this medicine cause?

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

• diarrhea
• nausea
• vomiting
• headache
• extreme tiredness

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately or get emergency medical treatment.

• rash
• itching
• hives, blisters, or peeling skin
• difficulty breathing or swallowing
• swelling of your face, eyes, lips, tongue, or throat
• sore throat, fever, chills, cough, and other signs of infection
• back or side pain
• blood in urine
• pain when urinating

Fosamprenavir 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 (https://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

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). The suspension may also be stored in the refrigerator, but do not freeze it.

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location — one that is up and away and out of their sight and reach. https://www.upandaway.org

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (https://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

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 https://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.

What OTHER INFORMATION should I know?

Keep all appointments with your doctor and the laboratory. Your doctor may order certain lab tests before and during your treatment to be sure it is safe for you to take fosamprenavir and to check your body's response to fosamprenavir.

Do not run out of medication. When your supply of fosamprenavir starts to run low, get more from your doctor or pharmacist.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry 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, 2024. 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: June 15, 2019.