What are the most important things to know about fostemsavir?
Fostemsavir can cause serious side effects. These include heart rhythm problems and liver problems.
Contact your health care provider right away if you have any of the following symptoms that could be signs of heart rhythm problems:
- Changes in your heartbeat
Some people taking fostemsavir have had liver problems. People with a history of hepatitis B virus infection (HBV) or hepatitis C virus infection (HCV) may have an increased risk of developing new or worsening liver problems while taking fostemsavir.
Contact your health care provider right away if you have any of the following symptoms that could be signs of liver problems:
- Yellowing of your skin or the whites of your eyes (jaundice)
- Dark-colored urine
- Light-colored bowel movements
- Loss of appetite for several days or longer
- Nausea or vomiting
- Pain, aching, or tenderness on the right side of your stomach/abdominal area
While taking fostemsavir, it is important to keep all of your appointments with your health care provider.
What is fostemsavir?
Fostemsavir (brand name: Rukobia) is a prescription medicine approved by the U.S. Food and Drug Administration (FDA) for the treatment of HIV infection in treatment-experienced adults who meet certain requirements, as determined by a health care provider. Fostemsavir is always used in combination with other HIV medicines.
For more information on the use of fostemsavir in people with HIV, please refer to the Guidelines for the Use of Antiretroviral Agents in Adults and Adolescents Living with HIV.
HIV medicines cannot cure HIV/AIDS, but taking HIV medicines every day helps people with HIV live longer, healthier lives. HIV medicines also reduce the risk of HIV transmission. If you are taking HIV medicines, do not cut down on, skip, or stop taking them unless your health care provider tells you to.
What should I tell my health care provider before taking fostemsavir?
Before taking fostemsavir, tell your health care provider:
- If you are allergic to fostemsavir or any other medicines.
- If you have ever had a heart problem, including QTc prolongation, which is a heart disorder that causes irregular heartbeats.
- If you have ever had liver problems, including HBV or HCV.
- If you have any other medical conditions.
- If you are pregnant or plan to become pregnant. Talk to your health care provider about the risks and benefits of taking fostemsavir during pregnancy. For more information on the use of fostemsavir during pregnancy, please refer to the Recommendations for the Use of Antiretroviral Drugs During Pregnancy and Interventions to Reduce Perinatal HIV Transmission in the United States.
- If you are breast/chestfeeding or plan to breast/chestfeed. For people with HIV in the United States, the Guideline recommends speaking with your health care provider to discuss options for feeding your baby. People with suppressed viral load have a less than 1% chance of transmitting HIV to their baby via their own milk.
- If you are using hormone-based birth control (such as pills, implants, or vaginal rings), especially if you are taking birth control pills that contain ethinyl estradiol. Your health care provider can help you decide how to adjust your birth control while you are taking fostemsavir. For more information about using birth control and HIV medicines at the same time, view the HIVinfo HIV and Birth Control infographic.
- About other prescription and nonprescription medicines, vitamins, nutritional supplements, and herbal products you are taking or plan to take (particularly St. John’s wort). Fostemsavir may affect the way other medicines or products work, and other medicines or products may affect how fostemsavir works. Taking fostemsavir together with certain medicines or products may cause serious side effects.
How should I take fostemsavir?
Fostemsavir comes in an extended-release tablet that contains 600 mg of fostemsavir.
Take fostemsavir according to your health care provider’s instructions. Do not miss a dose of fostemsavir, and do not change your dose or stop taking fostemsavir without first talking with your health care provider.
Swallow fostemsavir tablets whole. Do not chew, crush, or split the tablets before swallowing.
Fostemsavir can be taken with or without food.
Fostemsavir tablets may have a slight odor (like vinegar).
Always take fostemsavir in combination with other HIV medicines.
If you have taken too much fostemsavir, contact your health care provider or local poison control center (1-800-222-1222) right away, or go to the nearest hospital emergency room.
For more information on how to take fostemsavir, see the FDA drug label.
What should I do if I forget a dose?
If you miss a dose of fostemsavir, take the missed dose as soon as you remember it. But if it is almost time for your next dose, skip the missed dose and just take your next dose at the regular time. Do not take two doses at the same time to make up for a missed dose.
What side effects can fostemsavir cause?
Fostemsavir may cause side effects. Some side effects of fostemsavir can be serious as noted above. Many side effects from HIV medicines, such as nausea or occasional dizziness, are manageable. See the HIVinfo fact sheet on HIV Medicines and Side Effects for more information.
Another possible side effect of fostemsavir is a change in your immune system (called immune reconstitution inflammatory syndrome or IRIS). IRIS is a condition that sometimes occurs when the immune system begins to recover after treatment with an HIV medicine. As the immune system gets stronger, it may have an increased response to a previously hidden infection.
Tell your health care provider if you have any side effect that bothers you or that does not go away.
These are not all the possible side effects of fostemsavir. To learn more about possible side effects of fostemsavir, read the drug label or package insert or talk to your health care provider or pharmacist.
You can report side effects to FDA at 1-800-FDA-1088 (1-800-332-1088) or online.
How should fostemsavir be stored?
- Store fostemsavir at room temperature, 68°F to 77°F (20°C to 25°C).
- Keep fostemsavir in the container that it came in and keep the container tightly closed.
- Do not use fostemsavir if the original seal over the container opening is broken or missing.
- Throw away fostemsavir that is no longer needed or expired (out of date). Follow FDA guidelines on how to safely dispose of unused medicine.
- Keep fostemsavir and all medicines out of reach of children.
Where can I find more information about fostemsavir?
- For more information on the use of fostemsavir in people with HIV, please refer to the Guidelines for the Use of Antiretroviral Agents in Adults and Adolescents Living with HIV.
- This Patient Version drug summary is based on the following FDA label(s): Tablet (film-coated, extended-release). The Patient Package Insert includes information for people taking fostemsavir.
- The American Hospital Formulary Service (AHFS) Patient Medication Information for fostemsavir available from MedlinePlus.
- Fostemsavir-related research studies, from ClinicalTrials.gov. (The ClinicalTrials.gov search can be modified so that you can get results that better match your interests. To learn more about the ClinicalTrials.gov search features, please see How to Search.)
- A list of FDA-approved HIV medicines, from HIVinfo.
Main number: 877-844-8872
Patient assistance (ViiV Connect): 844-588-3288
Last Reviewed: June 30, 2022