Fostemsavir

Fostemsavir is an antiviral medicine that stops the human immunodeficiency virus (HIV) from growing in your body.

Fostemsavir is used along with other antiviral drugs to treat HIV, the virus that can lead to acquired immunodeficiency syndrome (AIDS). Fostemsavir is not a cure for HIV or AIDS.

Fostemsavir is given when several other HIV medications did not work or have stopped working.

Fostemsavir may also be used for reasons not mentioned in this medication guide.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

You may take fostemsavir with or without food.

Swallow the tablet whole and do not crush, chew, or break it.

Use all HIV medications as directed and read all medication guides you receive. Do not change your dose or dosing schedule without your doctor's advice. Every person with HIV should remain under the care of a doctor.

Store at room temperature away from moisture and heat.

It is normal for fostemsavir tablets to smell slightly like vinegar.

Follow all instructions on your medicine label and package. Inform each of your healthcare providers about all your medical conditions, allergies, and all medicines you are taking.

You should not use fostemsavir if you are allergic to it.

Many drugs can interact and cause harmful effects. Some drugs should not be taken together with fostemsavir. Your doctor may change your treatment plan if you also take:

• carbamazepine;
• enzalutamide;
• mitotane;
• phenytoin;
• rifampin; or
• St. John's wort.

Tell your doctor if you have ever had liver problems, especially hepatitis B or C.

Tell your doctor if you are pregnant, and use your medications correctly to manage your infection. HIV can be passed to your baby if the virus is not controlled during pregnancy. Your name may be added to a registry to monitor any effects of antiviral medicine on the baby.

Women with HIV or AIDS should not breastfeed a baby. Even if your baby is born without HIV, the virus may be transmitted to the baby through your breast milk.

Fostemsavir is not approved for use by anyone younger than 18 years old.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Fostemsavir may cause serious side effects. Call your doctor right away if you have:

• fast or pounding heartbeats, fluttering in your chest;
• shortness of breath; and
• sudden dizziness (like you might pass out).

Fostemsavir affects your immune system, which may cause certain side effects (even weeks or months after you've taken fostemsavir). Tell your doctor if you have:

• signs of a new infection--fever, night sweats, swollen glands, cold sores, cough, wheezing, diarrhea, weight loss;
• trouble speaking or swallowing, problems with balance or eye movement, weakness or prickly feeling; or
• swelling in your neck or throat (enlarged thyroid), menstrual changes, impotence.

Nausea is the most common side effect of fostemsavir.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Usual Adult Dose for HIV Infection:

600 mg orally twice a dayUse: In combination with other antiretroviral agent(s), for the treatment of HIV-1 infection in heavily treatment-experienced patients with multidrug-resistant HIV-1 infection failing their current antiretroviral regimen due to resistance, intolerance, or safety considerations

Take the medicine as soon as you can, but skip the missed dose if it is nearly time for your next dose. Do not take two doses at the same time.

Try not to miss any doses. Get your prescription refilled before you completely run out of medicine.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

If you have hepatitis B or C, using fostemsavir can cause new or worsening liver problems. You may need frequent liver function tests while using fostemsavir and for several months after you stop.

• Do not stop using any medication you take to treat hepatitis, unless your doctor tells you to.

Fostemsavir can lead to a serious heart issue. Your risk may be higher if you also take certain other medicines for infections, asthma, heart problems, high blood pressure, depression, mental illness, cancer, malaria, or HIV.

Inform your doctor if you take birth control pills or hormone replacement therapy that contains ethinyl estradiol. Fostemsavir can raise your blood levels of ethinyl estradiol, which may increase side effects of this medicine.

When you begin or stop taking fostemsavir, your doctor may need to change the doses of any "statin" cholesterol medicine you regularly take. This includes atorvastatin, lovastatin, pravastatin, rosuvastatin, simvastatin, Crestor, Vytorin, Zocor, and others.

Other medications may affect fostemsavir, including prescription and over-the-counter medicines, vitamins, and herbal products. Inform your doctor about all your current medicines and any medicine you start or stop using.