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Symfi Lo

Generic Name: efavirenz, lamivudine, and tenofovir (ef AV ir enz, la MIV ue deen, and ten OF oh vir)
Brand Name: Symfi, Symfi Lo

Medically reviewed by on May 4, 2018 – Written by Cerner Multum

What is Symfi Lo (Symfi Lo)?

Symfi Lo is a combination antiviral medicine that prevents human immunodeficiency virus (HIV) from multiplying in your body.

Symfi Lo is used to treat HIV in adults and children who weigh at least 77 pounds (35 kilograms). HIV is the virus that can cause acquired immunodeficiency syndrome (AIDS). Symfi Lo is not a cure for HIV or AIDS.

Symfi Lo may also be used for purposes not listed in this medication guide.

Important Information

You may develop lactic acidosis, a dangerous build-up of lactic acid in your blood. Call your doctor or get emergency medical help if you have unusual muscle pain, trouble breathing, stomach pain, dizziness, feeling cold, or feeling very weak or tired.

Call your doctor at once if you have swelling or pain in your upper stomach pain, unusual tiredness, loss of appetite, dark urine, clay-colored stools, or yellowing of the skin or eyes.

Symfi Lo may cause serious mental health problems. Get medical help if you have unusual sadness, paranoia, hallucinations, or thoughts about hurting yourself or others.

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

Before taking this medicine

You should not use Symfi Lo if:

Tell your doctor if you have ever had:

  • liver disease (especially hepatitis B or C); or

  • kidney disease (or if you are on dialysis);

  • mental illness or psychosis;

  • heart problems;

  • long QT syndrome (in you or a family member);

  • drug or alcohol addiction;

  • a seizure; or

  • fractures or other problems with your bones.

Use effective birth control to prevent pregnancy while you are using Symfi Lo and for at least 12 weeks after your last dose. Symfi Lo could harm an unborn baby or cause birth defects. You may need to have a negative pregnancy test before starting this treatment.

Use two forms of birth control to prevent pregnancy, including a barrier form such as a condom or a diaphragm with spermicide.

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 Symfi Lo?

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

Symfi Lo is a complete regimen and is not for use with other antiviral medications.

Take Symfi Lo 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 Symfi Lo. You may need frequent liver function for several months after your last dose.

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 Symfi Lo?

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

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

Symfi Lo 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).

Mild symptoms of lactic acidosis may worsen over time, and this condition can be fatal. Get emergency medical help if you have: unusual muscle pain, trouble breathing, stomach pain, vomiting, irregular heart rate, dizziness, feeling cold, or feeling very weak or tired.

Call your doctor at once if you have:

  • severe dizziness or drowsiness, trouble concentrating;

  • fast or pounding heartbeats, shortness of breath, feeling like you might pass out;

  • strange dreams, hallucinations;

  • new or worsening bone pain;

  • pain in your arms, legs, hands, or feet;

  • pancreatitis--severe pain in your upper stomach spreading to your back, nausea and vomiting;

  • unusual thoughts--fear, paranoia, feeling sad or hopeless, thoughts of hurting yourself or others; or

  • liver problems--swelling around your midsection, upper stomach pain, unusual tiredness, loss of appetite, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Symfi Lo 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 side effects may include:

  • dizziness;

  • rash; or

  • changes in the shape or location of body fat (especially in your arms, legs, face, neck, breasts, and waist).

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.

What other drugs will affect Symfi Lo?

Tell your doctor about all your other medicines, especially:

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

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.

Related questions

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