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Symfi Lo (Oral)

Generic name: efavirenz, lamivudine, and tenofovir [ ef-a-VYE-renz, la-MIV-ue-deen, ten-OF-oh-vir-dye-soe-PROX-il-FUE-ma-rate ]
Brand names: Symfi, Symfi Lo
Drug class: Antiviral combinations

Medically reviewed by Drugs.com. Last updated on Jan 2, 2024.

Oral route(Tablet)

Warning: Post treatment acute exacerbation of hepatitis BSevere acute exacerbations of hepatitis B have been reported in patients who are co-infected with hepatitis B virus (HBV) and human immunodeficiency virus (HIV-1) and have discontinued lamivudine or tenofovir disoproxil fumarate, two components of efavirenz/lamivudine/tenofovir disoproxil fumarate oral tablets. Monitor hepatic function closely in these patients and, if appropriate, initiate anti-hepatitis B treatment .

Uses for Symfi Lo

Efavirenz, lamivudine, and tenofovir combination is used alone to treat human immunodeficiency virus (HIV) infection. HIV is the virus that causes acquired immune deficiency syndrome (AIDS).

This medicine does not cure or prevent HIV or AIDS. It helps keep HIV from reproducing and appears to slow down the destruction of the immune system. This may help delay the development of problems that usually result from AIDS or HIV disease. It will not keep you from spreading HIV to other people. People who receive this medicine may continue to have some of the problems usually related to AIDS or HIV disease.

This medicine is available only with your doctor's prescription.

Before using Symfi Lo

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:

Allergies

Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.

Pediatric

Appropriate studies performed to date have not demonstrated pediatric-specific problems that would limit the usefulness of Symfi™ in children weighing 40 kilograms (kg) or more or Symfi Lo™ in children weighing 35 kg or more. Safety and efficacy have not been established in children weighing less than 40 kg using Symfi™ and in children weighing less than 35 kg using Symfi Lo™.

Geriatric

Appropriate studies performed to date have not demonstrated geriatric-specific problems that would limit the usefulness of efavirenz, lamivudine, and tenofovir combination in the elderly. However, elderly patients are more likely to have age-related kidney, liver, or heart problems, which may require caution in patients receiving efavirenz, lamivudine, and tenofovir combination.

Breast Feeding

There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.

Interactions with Medicines

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.

Interactions with Food/Tobacco/Alcohol

Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.

Other Medical Problems

The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:

Proper use of Symfi Lo

Take this medicine exactly as directed by your doctor. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered.

This medicine comes with a patient information insert. Read and follow the instructions in the insert carefully. Ask your doctor if you have any questions.

Do not change the dose or stop using this medicine without checking first with your doctor. When your supply of this medicine is running low, contact your doctor or pharmacist ahead of time. Do not allow yourself to run out of this medicine.

Take this medicine on an empty stomach, at the same time each day, preferably at bedtime.

Keep taking this medicine for the full time of treatment even if you begin to feel better. If you stop the medicine even briefly, the virus may become harder to treat.

Dosing

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

Missed Dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

Keep out of the reach of children.

Do not keep outdated medicine or medicine no longer needed.

Ask your healthcare professional how you should dispose of any medicine you do not use.

Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light. Keep from freezing.

Store the medicine in its original container. Keep the bottle tightly closed.

Detailed Symfi Lo dosage information

Precautions while using Symfi Lo

It is very important that your doctor check your and your child's progress at regular visits, especially during the first few weeks that you take this medicine. Blood and urine tests may be needed to check for any unwanted effects.

Do not use this medicine together with elbasvir/grazoprevir (Zepatier®).

Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant. You should not become pregnant while you are using this medicine and for 12 weeks after the last dose. Some birth control pills may not work as well while you are using this medicine. Use birth control pills together with another form of birth control (eg, condoms, diaphragm, or contraceptive foam or jelly). If you think you have become pregnant while using the medicine, tell your doctor right away.

Two rare but serious reactions to this medicine are lactic acidosis (too much acid in the blood) and liver toxicity. These reactions usually occur if you are a female and overweight. Call your doctor right away if you or child have abdominal or stomach discomfort, cramping, nausea, vomiting, diarrhea, or a decreased appetite, muscle cramping or pain, unusual tiredness or weakness, trouble breathing, or yellow skin or eyes.

This medicine may cause a hepatitis B infection to worsen if you stop using it. Your doctor may check for the presence of hepatitis B before and during treatment with this medicine and for at least several months after your last dose.

This medicine may increase the risk of kidney problems. To lower this risk, avoid other medicines that can be harmful to the kidneys such as aminoglycoside antibiotics, certain other antiviral medicines, and NSAID pain medicines.

You or your child might have mood or behavior changes with this medicine, such as feeling sad or hopeless, or getting upset easily. You could feel nervous or hostile, or have decreased awareness or responsiveness. Some people become violent and want to hurt themselves or others. Call your doctor right away if you or your child have any strange feelings, thoughts, or behaviors.

This medicine may cause nervous system symptoms and can be severe. These symptoms usually begin during the first or second day after taking this medicine and usually go away after 2 to 4 weeks of treatment. Some symptoms may occur months to years after starting treatment. Tell your doctor if you have confusion, trouble sleeping, unusual dreams, trouble concentrating, slow thoughts and movements while using this medicine.

This medicine may cause some people to become dizzy, lightheaded, drowsy, or less alert than they are normally. Even if taken at bedtime, it may cause some people to feel drowsy or less alert upon waking up. Do not drive or do anything else that could be dangerous unless you know how this medicine affects you.

Some people who have used this medicine developed serious skin problems. Call your doctor right away if you or your child notice a severe skin rash, blistering, peeling, or loosening of the skin, red skin lesions, sores or ulcers on the skin, or fever or chills while you or your child are using this medicine.

Check with your doctor right away if you or your child have loss of appetite, nausea, or pains in the stomach, side, or abdomen, possibly radiating to the back. These could be symptoms of pancreatitis (swelling of the pancreas).

This medicine may also increase your or your child's risk of developing fractures (broken bones). Ask your doctor about this if you have any concerns.

Your immune system may get stronger when you start taking HIV medicines. Tell your doctor right away if you notice any changes in your health. Sometimes the immune system will start to fight infections that were hidden in your body, such as pneumonia, herpes, or tuberculosis. Autoimmune disorders (eg, Graves' disease, polymyositis, and Guillain-Barré syndrome) may also occur.

This medicine may cause you to have excess body fat. Tell your doctor if you notice changes in your body shape, such as an increased amount of fat in the upper back and neck, or around the chest and stomach area. You might also lose fat from the legs, arms, and face.

Contact your doctor right away if you or your child have any changes in heart rhythm. You might feel dizzy or faint, or you might have a fast, pounding, or uneven heartbeat. Make sure your doctor knows if you or anyone in your family has ever had a heart rhythm problem such as QT prolongation.

Limit the amount of alcohol you drink.

Make sure any doctor or dentist who treats you knows that you or your child are using this medicine. This medicine may affect the results of certain medical tests.

This medicine does not decrease the risk of transmitting the HIV infection to others through sexual contact or by contaminated blood. Make sure you understand and practice safe sex, even if your partner also has HIV. Avoid sharing needles with anyone.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal (St. John's wort) or vitamin supplements.

Side Effects of Symfi Lo

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

More common

Less common

Incidence not known

Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Less common

Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Symfi Lo side effects (more detail)

Commonly used brand name(s)

In the U.S.

Available Dosage Forms:

Therapeutic Class: Antiretroviral Agent

Pharmacologic Class: Non-Nucleoside Reverse Transcriptase Inhibitor

Frequently asked questions

Further information

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

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