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Efavirenz, lamivudine, and tenofovir

Generic name: efavirenz, lamivudine, and tenofovir [ ef-AV-ir-enz, la-MIV-ue-deen, and-ten-OF-oh-vir ]
Brand names: Symfi, Symfi Lo
Dosage form: oral tablet (400 mg-300 mg-300 mg; 600 mg-300 mg-300 mg)
Drug class: Antiviral combinations

Medically reviewed by Drugs.com on Nov 23, 2023. Written by Cerner Multum.

What is efavirenz, lamivudine, and tenofovir?

Efavirenz, lamivudine, and tenofovir is a combination antiviral medicine that is used to treat human immunodeficiency virus (HIV). HIV is the virus that can cause acquired immunodeficiency syndrome (AIDS). efavirenz, lamivudine, and tenofovir is not a cure for HIV or AIDS.

Symfi is for use in adults and children who weigh at least 88 pounds (40 kilograms).

Symfi Lo is for use in adults and children who weigh at least 77 pounds (35 kilograms).

Efavirenz, lamivudine, and tenofovir may also be used for purposes not listed in this medication guide.

Side Effects

Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning in your eyes, skin pain, red or purple skin rash that spreads and causes blistering and peeling).

Efavirenz, lamivudine, and tenofovir may cause serious side effects. Call your doctor at once if you have:

Symfi 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:

Common side effects of efavirenz, lamivudine, and tenofovir may include:

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.

Warnings

If you've ever had hepatitis B, it may become active or get worse after you stop using this medicine. You may need frequent liver function tests for several months.

Do not change your dose or stop taking this medicine without your doctor's advice.

Before taking this medicine

You should not use this medicine if:

Tell your doctor if you have ever had:

You may develop lactic acidosis, a dangerous build-up of lactic acid in your blood. This may be more likely if you are overweight or if you are a woman. Ask your doctor about your risk.

You may need to have a negative pregnancy test before starting this treatment.

Do not use this medicine if you are pregnant. It could harm the unborn baby or cause birth defects. Use effective birth control to prevent pregnancy while you are using this medicine and for at least 12 weeks after your last dose.

Use two forms of birth control to prevent pregnancy, including a barrier form such as a condom, diaphragm, cervical cap, or contraceptive sponge.

If you are pregnant, your name may be listed on a pregnancy registry to track the effects of this medicine on the baby.

Women with HIV or AIDS should not breast feed a baby. Even if your baby is born without HIV, the virus may be passed to the baby in your breast milk.

How should I take efavirenz, lamivudine, and tenofovir?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Efavirenz, lamivudine, and tenofovir is a complete regimen and is not for use with other antiviral medications.

Take this medicine on an empty stomach at bedtime.

You will need frequent medical tests.

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 this medicine in the original container at room temperature, away from moisture and heat.

If you've ever had hepatitis B, this virus may become active or get worse in the months after you stop using this medicine. You may need frequent liver function for several months after your last dose.

Efavirenz, lamivudine, and tenofovir dosing information

Usual Adult Dose for HIV Infection:

1 tablet orally once a day

Use: As a complete regimen for the treatment of HIV-1 infection

Usual Pediatric Dose for HIV Infection:

1 tablet orally once a day

Comments:
-Symfi Lo(TM) is approved for patients weighing at least 35 kg.
-Symfi(TM) is approved for patients weighing at least 40 kg.
-Recommended for pediatric patients who can swallow a solid tablet

Use: As a complete regimen for the treatment of HIV-1 infection

What happens if I miss a dose?

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.

What happens if I overdose?

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

What should I avoid while taking efavirenz, lamivudine, and tenofovir?

Avoid eating or drinking anything that contains sorbitol (an artificial sweetener).

Avoid driving or hazardous activity until you know how this medicine will affect you. Your reactions could be impaired.

What other drugs will affect efavirenz, lamivudine, and tenofovir?

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Many drugs can affect efavirenz, lamivudine, and tenofovir. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here. Tell your doctor about all your current medicines and any medicine you start or stop using.

Frequently asked questions

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.