Ensitrelvir

Ensitrelvir is an antiviral medicine that helps prevent COVID-19 in adults and children who are at least 12 years old after being exposed to someone with COVID-19.

It is not known if ensitrelvir is safe and effective for children younger than 12 years old.

Ensitrelvir may also be used for other purposes 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.

Start taking ensitrelvir as soon as possible and within 72 hours after contact with a person who has COVID-19.

Take ensitrelvir once daily for 5 days. Take 3 tablets at one time on the first day. Then take 1 tablet once daily for the next 4 days. Do not stop taking ensitrelvir without talking to your doctor.

Take ensitrelvir with or without food, at about the same time each day.

Do not remove ensitrelvir tablets from the blister pack until you are ready to take your dose.

Store ensitrelvir at room temperature in the original package.

Ensitrelvir can interact with many medicines. Some medicines should not be used with ensitrelvir because serious or life-threatening side effects could happen. Inform your doctor about all medicines you are taking.

Ensitrelvir may harm an unborn baby. Use effective birth control while taking ensitrelvir and for 2 weeks after your last dose.

You should not take ensitrelvir if you are allergic to ensitrelvir or any of the ingredients in ensitrelvir.

Some drugs should not be used with ensitrelvir. Do not take ensitrelvir if you take any of these medicines: apalutamide, carbamazepine, colchicine, dihydroergotamine, enzalutamide, eplerenone, ergotamine, finerenone, ivabradine, lomitapide, lumacaftor with ivacaftor, lurasidone, methylergonovine, phenytoin, pimozide, quinidine, rifampin, St. John's wort, simvastatin, triazolam, or voclosporin. These are not the only medicines that may cause serious or life-threatening side effects.

Your doctor will check to see if you are pregnant before you start ensitrelvir.

Tell your doctor if you are pregnant or plan to become pregnant. Ensitrelvir may harm an unborn baby.

Use effective birth control while using ensitrelvir and for 2 weeks after your last dose. Tell your doctor right away if you become pregnant or think you may be pregnant.

Do not breastfeed while using ensitrelvir and for 2 weeks after your last dose.

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

Stop using ensitrelvir and seek medical help immediately if you experience:

• difficulty swallowing or breathing;
• tightness in your throat;
• dizziness or feeling light-headed; or
• stomach pain or vomiting.

Common side effects of ensitrelvir may include:

• headache;
• diarrhea; or
• cough.

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

Usual Adult Dose for COVID-19 Prophylaxis:

Day 1: 375 mg orally onceDays 2 to 5: 125 mg orally once a dayDuration of therapy: 5 daysComments:-Therapy should begin as soon as possible and within 72 hours following contact with an individual who has COVID-19.-Tablets should be taken together on Day 1.Use: For post-exposure prophylaxis of COVID-19 following contact with an individual who has COVID-19

Usual Pediatric Dose for COVID-19 Prophylaxis:

12 years and olderDay 1: 375 mg orally onceDays 2 to 5: 125 mg orally once a dayDuration of therapy: 5 daysComments:-Therapy should begin as soon as possible and within 72 hours following contact with an individual who has COVID-19.-Tablets should be taken together on Day 1.Use: For post-exposure prophylaxis of COVID-19 following contact with an individual who has COVID-19

If you forget a dose, take it as soon as you can on the same day. Then go back to your usual schedule the next day. Do not take two doses at once.

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

Do not share ensitrelvir with another person, even if they have the same symptoms you have.

Avoid taking an herbal supplement containing St. John's wort.

Sometimes it is not safe to use certain medicines together. Some drugs can change the levels of other drugs in your blood, which may increase side effects or make the medicines less effective.

Do not start taking a new medicine without informing your doctor.

Other drugs may affect ensitrelvir, including prescription and over-the-counter medicines, vitamins, and herbal products. Inform your doctor about all other medicines you are using.