Pifeltro

Pifeltro is a prescription medication used to treat human immunodeficiency virus (HIV)-1 infection in adult patients who have not previously received HIV-1 treatment. Pifeltro should be taken in combination with other medicines that also treat HIV-1. Pifeltro belongs to a group of drugs called retrovirals. Pifeltro acts by inhibiting HIV-1 replication by inhibiting an enzyme needed by the virus to replicate, this enzyme is called HIV-1 reverse transcriptase.

Pifeltro is a single product containing doravirine. It comes in tablet form and should be taken by mouth once a day, if taken alone. If taken with rifabutin, increase to one table by mouth twice daily. This medication is swallowed whole, with or without food. 

Common side effects include nausea, dizziness, headache, fatigue, diarrhea, abdominal pain, and abnormal dreams.

Pifeltro is a prescription medicine that is used together with other antiretroviral medicines to treat Human Immunodeficiency Virus-1 (HIV-1) infection in adults who have not taken HIV-1 medicines before.

It is not known if Pifeltro is safe and effective in children under 18 years of age.

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

• Merck Sharp & Dohme Corp.

Serious side effects have been reported with Pifeltro. See the “Drug Precautions” section.

Common side effects include:

• Nausea
• Headache
• Fatigue
• Diarrhea
• Abdominal Pain
• Dizziness
• Rash
• Abnormal dreams
• Insomnia
• Somnolence

This is not a complete list of Pifeltro side effects. Ask your doctor or pharmacist for more information. Tell your doctor if you have any side effect that is bothering you or does not go away. Call your doctor for medical advice regarding any side effect. You may report side effects to the FDA at 1-800-FDA-1088.

Before starting Pifeltro talk to your doctor about all the medicines you are taking. Include prescription medication, non-prescription medication, vitamins, and supplements. Especially tell your doctor if you take any of the following:

• carbamazepine, oxcarbazepine, phenobarbital, phenytoin

• enzalutamide

• rifampin, rifapentine

• mitotane

• St. John's wort (Hypericum perforatum)

Ask your doctor or pharmacist if you are not sure if your medicine is one that is listed above. If you have taken any of the medicines in the past 4 weeks, talk to your doctor or pharmacist before starting treatment with Pifeltro.

This is not a complete list of Pifeltro drug interactions. Ask your doctor or pharmacist for more information regarding potential drug interactions while taking Pifeltro.

Pifeltro can cause serious side effects, including:

Changes in your immune system (Immune Reconstitution Syndrome) can happen when you start taking HIV-1 medicines. Your immune system may get stronger and begin to fight infections that have been hidden in your body for a long time. Tell your doctor right away if you start having any new symptoms after starting your HIV-1 medicine.

The most common side effects of Pifeltro include:

• nausea
• dizziness
• headache
• tiredness
• diarrhea
• stomach (abdominal) pain
• abnormal dreams

These are not all the possible side effects of Pifeltro.
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Medications can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of Pifeltro, there are no specific foods that you must exclude from your diet when receiving this medication.

Before treatment with Pifeltro, tell your doctor about all of your medical conditions, including if you:

• are pregnant or plan to become pregnant. It is not known if Pifeltro can harm your unborn baby. Tell your healthcare provider if you become pregnant during treatment with Pifeltro. Pregnancy Registry: There is a pregnancy registry for people who take Pifeltro during pregnancy. The purpose of this registry is to collect information about the health of you and your baby. Talk to your doctor about how you can take part in this registry.
• are breastfeeding or plan to breastfeed. Do not breastfeed if you take Pifeltro.
  • You should not breastfeed if you have HIV-1 because of the risk of passing HIV-1 to your baby.
  • It is not known if Pifeltro can pass into your breast milk.
  • Talk with your doctor about the best way to feed your baby.

Tell your doctor about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

• Some medicines interact with Pifeltro. Keep a list of your medicines to show your doctor and pharmacist.
• Tell your doctor if you have taken rifabutin in the past 4 weeks.
• You can ask your doctor or pharmacist for a list of medicines that interact with Pifeltro.
• Do not start taking a new medicine without telling your doctor. Your doctor can tell you if it is safe to take Pifeltro with other medicines.

Tell your doctor if you are or are planning to become pregnant.

There are no well-controlled studies that have been done in humans with Pifeltro to establish whether or not Pifeltro should be used during pregnancy. Pilfeltro should be used during pregnancy only if the possible benefit outweighs the possible risk to the unborn baby.

Healthcare providers are encouraged to register patients to a pregnancy exposure registry that monitors pregnancy outcomes in individuals exposed to Pifeltro during pregnancy by calling the Antiretroviral Pregnancy Registry (APR) at 1-800-258-4263.

Tell your doctor if you are breastfeeding or plan to breastfeed.

Pifeltro should not be used if a woman is breastfeeding. It is unknown whether Pifeltro is present in human milk, affects human milk production, or has effects on the breastfed infant. However, the Centers for Disease Control and Prevention recommend that HIV-1-infected mothers in the United States do not breastfeed their infants to avoid risking potential transmission of HIV-1 infection.

• Take Pifeltro every day exactly as your doctor tells you to take it.
• Take Pifeltro 1 time each day, at about the same time every day.
• If you take the medicine rifabutin during treatment with Pifeltro, take Pifeltro 2 times each day, about 12 hours apart, as prescribed by your doctor. You may not have enough doravirine in your blood if you take rifabutin during treatment with Pifeltro.
• Take Pifeltro with or without food.
• Do not change your dose or stop taking Pifeltro without talking to your doctor. Stay under a doctor’s care when taking Pifeltro.
• It is important that you do not miss or skip doses of Pifeltro.
• Do not take 2 doses of Pifeltro at the same time.
• If you have any questions, call your doctor or pharmacist.
• When your Pifeltro supply starts to run low, get more from your doctor or pharmacy. This is very important because the amount of virus in your blood may increase if the medicine is stopped for even a short time. The virus may develop resistance to Pifeltro and become harder to treat.

Take this medication exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.

The dose your doctor recommends may be based on other medications you are taking.

The recommended dose range of Pilfeltro for the treatment of HIV-1 is 100 mg orally once or twice daily.

If you take too much Pifeltro call your healthcare provider or local Poison Control Center, or seek emergency medical attention right away.

• Store Pifeltro tablets at room temperature between 68°F to 77°F (20°C to 25°C).
• Keep Pifeltro in the original bottle.
• Do not take the tablets out of the bottle to store in another container, such as a pill box.
• Keep the bottle tightly closed to protect Pifeltro from moisture.
• The Pifeltro bottle contains a desiccant to help keep your medicine dry (protect it from moisture). Keep the desiccant in the bottle. Do not eat the desiccant.
• Keep Pifeltro and all medicines out of the reach of children.

This page was written by Maria Delgado, PharmD Candidate 2020 | UT Austin College of Pharmacy