Pifeltro is an antiviral medicine that prevents human immunodeficiency virus (HIV) from multiplying in your body. HIV-1 is the virus that can cause acquired immunodeficiency syndrome (AIDS). 

Pifeltro is used to treat Human Immunodeficiency Virus-1 (HIV-1) infection in adults and children who weigh at least 77 pounds (35 kg):

• who have not received HIV-1 medicines in the past, or
• to replace their current HIV-1 medicines for people whose healthcare provider determines that they meet certain requirements.

It is not known if Pifeltro is safe and effective in children who weigh less than 77 pounds (35 kg).

Pifeltro is not a cure for HIV or AIDS.

Tell your doctor about all your current medicines and any you start or stop using. Many drugs can interact with Pifeltro, and some drugs should not be used together.

Pifeltro side effects

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

Doravirine affects your immune system, which may cause certain side effects (even weeks or months after you've taken this medicine). 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.

Common Pifeltro side effects may include:

• nausea, diarrhea, stomach pain;

• headache, dizziness;

• tiredness; or

• strange dreams.

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.

Take Pifeltro exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets.

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

Pifeltro is usually taken once per day. If you also take a medicine called rifabutin, you may need to take doravirine twice per day. Follow your doctor's dosing instructions very carefully.

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 tablets at room temperature, away from moisture and heat. Keep the tablets in their original container, along with the packet or canister of moisture-absorbing preservative.

Do not put the tablets into a daily pill box.

Usual Adult Dose for HIV Infection:

100 mg orally once a day

Use: In combination with other antiretroviral agents, for the treatment of HIV-1 infection in patients: with no prior antiretroviral treatment history, OR to replace the current antiretroviral regimen in patients virologically-suppressed (HIV-1 RNA less than 50 copies/mL) on a stable antiretroviral regimen with no history of treatment failure and no known substitutions associated with resistance to this drug

Usual Pediatric Dose for HIV Infection:

At least 35 kg: 100 mg orally once a day

Use: In combination with other antiretroviral agents, for the treatment of HIV-1 infection in patients: with no prior antiretroviral treatment history, OR to replace the current antiretroviral regimen in patients virologically-suppressed (HIV-1 RNA less than 50 copies/mL) on a stable antiretroviral regimen with no history of treatment failure and no known substitutions associated with resistance to this drug

You should not use Pifeltro if you are allergic to doravirine.

Many drugs can interact and cause dangerous effects. Some drugs should not be used together with Pifeltro. Your doctor may change your treatment plan if you have used any of the following medicines in the past 4 weeks:

• enzalutamide;

• mitotane;

• rifampin;

• rifapentine;

• St. John's wort; or

• seizure medicine - carbamazepine, phenobarbital, phenytoin, or oxcarbazepine.

Tell your doctor if you are pregnant, and use your medications properly to control your infection. HIV can be passed to your baby if the virus is not controlled during pregnancy. Your name may be listed on a registry to track 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 passed to the baby in your breast milk.

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

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

Get your prescription refilled before you run out of medicine completely. Skipping doses may increase the risk of your virus becoming resistant to medication.

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

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

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

Doravirine affects your immune system, which may cause certain side effects (even weeks or months after you've taken this medicine). 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.

Common Pifeltro side effects may include:

• nausea, diarrhea, stomach pain;

• headache, dizziness;

• tiredness; or

• strange dreams.

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.

Tell your doctor about all your other medicines, especially:

• rifabutin (or if you have taken it in the past 4 weeks).

This list is not complete. Other drugs may interact with doravirine, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.