Ensitrelvir

Ensitrelvir is used to prevent coronavirus disease 2019 (COVID-19 infection) caused by the SARS-CoV-2 virus that may occur following contact with someone with COVID-19. Ensitrelvir is in a class of medications called antivirals. It works by stopping the virus from spreading in the body.

Ensitrelvir comes as a tablet to take by mouth. Take with or without food once a day for 5 days. Take ensitrelvir at around the same time every day. Ensitrevlir should be started as soon as possible and within 72 hours of exposure.

Take ensitrelvir exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

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

Before taking ensitrelvir,

• tell your doctor or pharmacist if you are allergic to this medication, any part of this medication, or any other medications, foods or substances. Tell your doctor or pharmacist about the allergy and what symptoms you had.
• you should know that some medications should not be taken with ensitrelvir. Other medications may cause dosing changes or extra monitoring when taken with ensitrelvir. Make sure you have discussed any medications you are currently taking or plan to take before starting ensitrelvir with your doctor and pharmacist. Before starting, stopping, or changing any medications while taking ensitrelvir, please get the advice of your doctor or pharmacist.
• you should know the following nonprescription or herbal products may interact with ensitrelvir: St. John's Wort. Be sure to let your doctor and pharmacist know that you are taking these medications before you start taking ensitrelvir. Do not start any of these medications while taking ensitrelvir without discussing with your healthcare provider.
• tell your doctor if you have or have ever had liver disease.
• tell your doctor if you are pregnant or plan to become pregnant. You should not become pregnant while you are taking ensitrelvir. You may have to take a pregnancy test before starting treatment. You should use effective birth control to prevent pregnancy during your treatment and for 2 weeks after your final dose. Talk to your doctor about the best birth control method for you. If you become pregnant while taking ensitrelvir, call your doctor immediately. Ensitrelvir may harm the fetus.
• tell your doctor if you are breastfeeding or planning to breastfeed. You should not breastfeed while taking ensitrelvir and for at least 2 weeks after your final dose.

Talk to your doctor about eating grapefruit and drinking grapefruit juice while taking this medication.

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

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.

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

• headache
• diarrhea
• cough

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

• rash; hives; blisters on the skin; itching; difficulty breathing or swallowing

Ensitrelvir 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).

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). Keep the tablets in the foil blister pack until ready to take the dose.

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. https://www.upandaway.org

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 https://goo.gl/c4Rm4p for more information.

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.

Keep all appointments with your doctor.

Do not let anyone else take your medication. Your prescription is probably not refillable. If you still have symptoms of infection after you finish the ensitrelvir, call your doctor.

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.

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