What are the most important things to know about Symfi Lo?
Symfi Lo can cause serious, life-threatening side effects. These include a buildup of lactic acid in the blood (lactic acidosis), liver problems, new or worsening kidney problems, including kidney failure, mental health problems, and severe skin rash and allergic reactions.
Contact your health care provider right away if you have any of the following symptoms that could be signs of lactic acidosis:
- Weakness or tiredness
- Unusual muscle pain
- Shortness of breath or fast breathing
- Stomach pain with nausea or vomiting
- Cold or blue hands and feet
- Dizziness or lightheadedness
- Fast or abnormal heartbeat
Some people taking efavirenz, a component of Symfi Lo, may develop liver problems. People with a history of hepatitis B virus infection (HBV) or hepatitis C virus infection (HCV) or who have elevated results on liver function tests may have an increased risk of developing new or worsening liver problems while taking Symfi Lo. Liver problems have also occurred in people without a history of liver problems or other risk factors.
Contact your health care provider right away if you have any of the following symptoms that could be signs of liver problems:
- Yellowing of your skin or the whites of your eyes (jaundice)
- Dark-colored urine
- Light-colored bowel movements
- Loss of appetite for several days or longer
- Nausea and vomiting
- Pain, aching, or tenderness on the right side of your stomach/ abdominal area
If you have both HIV and HBV and take Symfi Lo, your HBV infection may get much worse (flare up) if you stop taking Symfi Lo. Do not stop taking Symfi Lo without first talking to your health care provider.
Contact your health care provider right away if you have any of the following symptoms that could be signs of a worsening kidney problem (called Fanconi Syndrome), which may be related to tenofovir-containing drugs:
- Bone pain that does not go away or gets worse
- Pain in your arms, hands, legs, or feet
- Broken bones
- Muscle pain or weakness
Contact your health care provider right away if you have any of the following symptoms that could be signs of mental health problems:
- Feeling sad or hopeless
- Feeling anxious or restless
- Not trusting other people
- Hearing or seeing things that are not real
- Not being able to move or speak normally
- Harming yourself or others or having thoughts about harming yourself (including suicidal thoughts)
- Not being able to tell the difference between what is true or real and what is false or unreal
Contact your health care provider right away if you develop a rash while taking Symfi Lo. Stop taking Symfi Lo and get medical help right away if you develop a rash with any of the following symptoms:
- General ill feeling
- Extreme tiredness
- Muscle or joint aches
- Blistering or peeling skin
- Blisters or sores in your mouth
- Redness or swelling of the eyes (conjunctivitis)
- Swelling of your face, lips, mouth, tongue, or throat
- Trouble breathing or swallowing
While taking Symfi Lo, it is important to keep all of your appointments with your health care provider.
What is Symfi Lo?
Symfi Lo is a prescription medicine approved by the U.S. Food and Drug Administration (FDA) for the treatment of HIV infection in adults and children weighing at least 77 lb (35 kg).
Symfi Lo is a complete HIV treatment regimen and should not be used with other HIV medicines.
Symfi Lo contains three different medicines: efavirenz, lamivudine, and tenofovir disoproxil fumarate.
For more information on the use of Symfi Lo in people with HIV, please refer to the Guidelines for the Use of Antiretroviral Agents in Adults and Adolescents with HIV and the Guidelines for the Use of Antiretroviral Agents in Pediatric HIV Infection.
HIV medicines cannot cure HIV/AIDS, but taking HIV medicines every day helps people with HIV live longer, healthier lives. HIV medicines also reduce the risk of HIV transmission. If you are taking HIV medicines, do not cut down on, skip, or stop taking them unless your health care provider tells you to.
What should I tell my health care provider before taking Symfi Lo?
Before taking Symfi Lo, tell your health care provider:
- If you are allergic to any of the HIV medicines in Symfi Lo (efavirenz, lamivudine, and tenofovir disoproxil fumarate) or any other medicines.
- If you have liver problems, including hepatitis B virus infection (HBV) or hepatitis C virus infection (HCV).
- If you have kidney problems, including end-stage renal disease (ESRD) that requires dialysis.
- If you have a history of mental health problems.
- If you have a history of drug or alcohol abuse.
- If you have heart problems, including QT prolongation.
- If you have bone problems, including a history of bone fractures.
- If you have a history of seizures.
- If you have any other medical conditions.
- If you are pregnant or plan to become pregnant. Talk to your health care provider about the risks and benefits of taking Symfi Lo during pregnancy. For more information on the use of Symfi Lo during pregnancy, please refer to the Recommendations for the Use of Antiretroviral Drugs During Pregnancy and Interventions to Reduce Perinatal HIV Transmission in the United States.
- If you are breast/chestfeeding or plan to breast/chestfeed. For people with HIV in the United States, the Guideline recommends speaking with your health care provider to discuss options for feeding your baby. People with suppressed viral load have a less than 1% chance of transmitting HIV to their baby via their own milk.
- If you are using hormone-based birth control (such as pills, implants, or vaginal rings). For more information about using birth control and HIV medicines at the same time, view the HIVinfo HIV and Birth Control infographic.
- About other prescription and nonprescription medicines, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Symfi Lo may affect the way other medicines or products work, and other medicines or products may affect how Symfi Lo works. Taking Symfi Lo together with certain medicines or products may cause serious side effects.
How should I take Symfi Lo?
Symfi Lo comes in tablet form. Each tablet contains:
- 400 mg efavirenz
- 300 mg lamivudine
- 300 mg tenofovir disoproxil fumarate
Take Symfi Lo according to your health care provider’s instructions. Do not miss a dose of Symfi Lo, and do not change your dose or stop taking Symfi Lo without first talking with your health care provider.
Take Symfi Lo on an empty stomach and preferably at bedtime. Taking Symfi Lo at bedtime might help to make some of the side effects less bothersome.
If you have taken too much Symfi Lo, contact your health care provider or local poison control center (1-800-222-1222) right away, or go to the nearest hospital emergency room.
For more information on how to take Symfi Lo, see the FDA drug label.
What should I do if I forget a dose?
If you miss a dose of Symfi Lo, take the missed dose as soon as you remember it. But if it is almost time for your next dose, skip the missed dose and just take your next dose at the regular time. Do not take two doses at the same time to make up for a missed dose.
What side effects can Symfi Lo cause?
Symfi Lo may cause side effects. Some side effects of Symfi Lo can be serious as noted above. Many side effects from HIV medicines, such as nausea or occasional dizziness, are manageable. See the HIVinfo fact sheet on HIV Medicines and Side Effects for more information.Other possible side effects of Symfi Lo include:
- Nervous system symptoms (including dizziness, trouble concentrating, drowsiness, trouble sleeping, unusual dreams, lack of coordination or balance, delusions, and hallucinations).
- Inflammation of the pancreas (pancreatitis) in some children. Contact your health care provider right away if your child develops signs and symptoms of pancreatitis, including severe pain in the upper stomach/abdominal area, with or without nausea and vomiting.
- Seizures, which are more likely to happen if you have had seizures in the past.
- Increases in blood fat levels, such as cholesterol and triglycerides.
- Bone problems, including bone pain, or softening or thinning of the bones (osteopenia), which may lead to fractures.
- Changes in your immune system (called immune reconstitution inflammatory syndrome or IRIS). IRIS is a condition that sometimes occurs when the immune system begins to recover after treatment with an HIV medicine. As the immune system gets stronger, it may have an increased response to a previously hidden infection.
- Changes in body fat (lipodystrophy syndrome).
- QT prolongation, which is a heart disorder that causes irregular heartbeats. QT prolongation can be life-threatening. Contact your health care provider if you feel faint, lightheaded, dizzy, or feel your heart beating irregularly or fast during treatment with Symfi Lo.
Tell your health care provider if you have any side effect that bothers you or that does not go away.
These are not all the possible side effects of Symfi Lo. To learn more about possible side effects of Symfi Lo, read the drug label or package insert or talk to your health care provider or pharmacist.
You can report side effects to FDA at 1-800-FDA-1088 (1-800-332-1088) or online.
How should Symfi Lo be stored?
- Store Symfi Lo below 86°F (30°C).
- Keep Symfi Lo in the container that it came in and keep the container tightly closed. If the container has a small packet of drying agent (called a desiccant), do not remove it. The desiccant protects the medicine from moisture.
- Do not use Symfi Lo if the original seal over the container opening is broken or missing.
- Throw away Symfi Lo that is no longer needed or expired (out of date). Follow FDA guidelines on how to safely dispose of unused medicine.
- Keep Symfi Lo and all medicines out of reach of children.
Where can I find more information about Symfi Lo?
- For more information on the use of Symfi Lo in people with HIV, please refer to the Guidelines for the Use of Antiretroviral Agents in Adults and Adolescents with HIV and the Guidelines for the Use of Antiretroviral Agents in Pediatric HIV Infection.
- This Patient Version drug summary is based on the following FDA label(s): Tablet. The Patient Information section includes information for people taking Symfi Lo.
- The American Hospital Formulary Service (AHFS) Patient Medication Information for efavirenz, lamivudine, and tenofovir available from MedlinePlus.
- Symfi Lo-related research studies, from ClinicalTrials.gov. (The ClinicalTrials.gov search can be modified so that you can get results that better match your interests. To learn more about the ClinicalTrials.gov search features, please see How to Search.)
- A list of FDA-approved HIV medicines, from HIVinfo.
Main number: 724-514-1800
Patient assistance: 800-796-9526
Last Reviewed: March 27, 2023