Symfi Lo Side Effects

Generic name: efavirenz / lamivudine / tenofovir disoproxil

Medically reviewed by Drugs.com. Last updated on Jan 6, 2025.

Note: This document provides detailed information about Symfi Lo Side Effects associated with efavirenz / lamivudine / tenofovir disoproxil. Some dosage forms listed on this page may not apply specifically to the brand name Symfi Lo.

Applies to efavirenz / lamivudine / tenofovir disoproxil: oral tablet.

Precautions

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.

Serious side effects of Symfi Lo

Along with its needed effects, efavirenz/lamivudine/tenofovir disoproxil 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 while taking efavirenz/lamivudine/tenofovir disoproxil:

Other side effects of Symfi Lo

Some side effects of efavirenz / lamivudine / tenofovir disoproxil 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:

For healthcare professionals

Applies to efavirenz / lamivudine / tenofovir disoproxil: oral tablet.

General adverse events

In a controlled trial with efavirenz, lamivudine, and tenofovir disoproxil fumarate (DF), the most common side effects were mild-to-moderate gastrointestinal events and dizziness. Mild side effects (grade 1) were common and included dizziness, diarrhea, and nausea.

In a controlled trial with efavirenz (400 or 600 mg) in combination with fixed-dose emtricitabine-tenofovir DF, the most common side effects were mild-to-moderate gastrointestinal events, dizziness, abnormal dreams, and rash.^[Ref]

Nervous system

• Very common (10% or more): Headache (14%)
• Common (1% to 10%): Dizziness
• Uncommon (0.1% to 1%): Peripheral neuropathy (included peripheral neuritis, neuropathy)

Efavirenz (with emtricitabine-tenofovir DF):

• Very common (10% or more): Dizziness (up to 35%), headache (up to 11%)
• Common (1% to 10%): Herpes zoster, somnolence

Efavirenz:

• Very common (10% or more): Central nervous system symptoms (53%), dizziness (28.1%)
• Common (1% to 10%): Impaired concentration, somnolence
• Postmarketing reports: Abnormal coordination, ataxia, cerebellar coordination and balance disturbances, convulsions, hypoesthesia, paresthesia, neuropathy, tremor, vertigo, tinnitus^[Ref]

Central nervous system (CNS) symptoms were reported in 53% of patients using efavirenz; these symptoms generally began the first or second day of therapy and often resolved after 2 to 4 weeks. CNS symptoms (any grade, regardless of causality) included, but were not limited to, dizziness, insomnia, impaired concentration, somnolence, abnormal dreams, and hallucinations. These symptoms were severe in 2% of patients; therapy was discontinued in 2.1% of patients due to these side effects. After 4 weeks of therapy, CNS symptoms of at least moderate severity were reported in 5% to 9% of patients using efavirenz-containing regimens.^[Ref]

Dermatologic

• Very common (10% or more): Rash event (included rash, pruritus, maculopapular rash, urticaria, vesiculobullous rash, pustular rash; 18%)

Efavirenz (with emtricitabine-tenofovir DF):

• Very common (10% or more): Rash event (included allergic dermatitis, drug hypersensitivity, generalized pruritus, eosinophilic pustular folliculitis, rash, erythematous rash, generalized rash, macular rash, maculopapular rash, morbilliform rash, papular rash, pruritic rash, vesicular rash, urticaria; up to 32%)
• Common (1% to 10%): Grade 3 to 4 rash

Efavirenz:

• Very common (10% or more): New-onset skin rash (26%)
• Uncommon (0.1% to 1%): Rash associated with blistering/moist desquamation/ulceration, grade 4 rash (e.g., erythema, multiforme, Stevens-Johnson syndrome)
• Postmarketing reports: Erythema multiforme, photoallergic dermatitis, Stevens-Johnson syndrome

Lamivudine:

• Postmarketing reports: Urticaria, alopecia, pruritus

Tenofovir DF:

• Postmarketing reports: Rash^[Ref]

Rashes associated with efavirenz were usually mild-to-moderate maculopapular skin eruptions. The median time to onset of rash was 11 days. In most patients who continued therapy, the rash resolved within 1 month. Treatment was discontinued due to rash in 1.7% of patients.^[Ref]

Metabolic

• Very common (10% or more): Elevated fasting cholesterol (19%)
• Uncommon (0.1% to 1%): Lipodystrophy, elevated fasting triglycerides
• Frequency not reported: Higher 1,25 vitamin D levels

Efavirenz (with emtricitabine-tenofovir DF):

• Common (1% to 10%): Cholesterol abnormal

Efavirenz:

• Postmarketing reports: Hypercholesterolemia, hypertriglyceridemia, redistribution/accumulation of body fat

Lamivudine:

• Postmarketing reports: Hyperglycemia, lactic acidosis, redistribution/accumulation of body fat

Tenofovir DF:

• Postmarketing reports: Lactic acidosis, hypokalemia, hypophosphatemia

Combination antiretroviral therapy:

• Frequency not reported: Redistribution/accumulation of body fat (including central obesity, dorsocervical fat enlargement, peripheral wasting, facial wasting, breast enlargement, "cushingoid appearance")^[Ref]

Elevated fasting cholesterol (greater than 240 mg/dL) and fasting triglycerides (greater than 750 mg/dL) have been reported in 19% and 1% of patients using efavirenz, lamivudine, and tenofovir DF, respectively.

Lactic acidosis and severe hepatomegaly with steatosis (including fatal cases) have been reported with the use of nucleoside analogs.

Hypokalemia and hypophosphatemia may occur as a result of proximal renal tubulopathy.^[Ref]

Other

• Very common (10% or more): Pain (13%)
• Common (1% to 10%): Fever, asthenia

Efavirenz (with emtricitabine-tenofovir DF):

• Common (1% to 10%): Pyrexia, phosphorus abnormal

Efavirenz:

• Frequency not reported: False-positive urine cannabinoid test results
• Postmarketing reports: Asthenia, flushing

Lamivudine:

• Postmarketing reports: Weakness

Tenofovir DF:

• Postmarketing reports: Asthenia^[Ref]

False-positive urine cannabinoid test results have been observed with some screening assays in uninfected and HIV-infected subjects using efavirenz.^[Ref]

Musculoskeletal

• Very common (10% or more): Elevated creatine phosphokinase (12%)
• Common (1% to 10%): Back pain, arthralgia, myalgia
• Frequency not reported: Decreased bone mineral density, increased biochemical markers of bone metabolism (serum bone-specific alkaline phosphatase, serum osteocalcin, serum C telopeptide, urinary N telopeptide), clinically relevant fractures (excluding fingers and toes)

Efavirenz:

• Postmarketing reports: Arthralgia, myalgia, myopathy

Lamivudine:

• Postmarketing reports: Muscle weakness, elevated creatine phosphokinase, rhabdomyolysis

Tenofovir DF:

• Postmarketing reports: Rhabdomyolysis, osteomalacia (manifested as bone pain and which may contribute to fractures), muscular weakness, myopathy^[Ref]

Elevated creatine phosphokinase (males: greater than 990 units/L; females: greater than 845 units/L) has been reported in 12% of patients using efavirenz, lamivudine, and tenofovir DF.

Rhabdomyolysis, osteomalacia, muscular weakness, and myopathy may occur as a result of proximal renal tubulopathy.^[Ref]

Gastrointestinal

• Very common (10% or more): Diarrhea (11%)
• Common (1% to 10%): Nausea, increased serum amylase, abdominal pain, dyspepsia, vomiting

Efavirenz (with emtricitabine-tenofovir DF):

• Common (1% to 10%): Diarrhea, vomiting, gastroenteritis

Efavirenz:

• Postmarketing reports: Constipation, malabsorption

Lamivudine:

• Frequency not reported: Pancreatitis

Tenofovir DF:

• Postmarketing reports: Pancreatitis, increased amylase, abdominal pain^[Ref]

Increased serum amylase (greater than 175 units/L) has been reported in 9% of patients using efavirenz, lamivudine, and tenofovir DF.

Pancreatitis (some cases fatal) has been reported in antiretroviral nucleoside-experienced pediatric patients using lamivudine alone or in combination with other antiretroviral agents.^[Ref]

Psychiatric

• Very common (10% or more): Depression (11%)
• Common (1% to 10%): Anxiety, insomnia, abnormal dreams

Efavirenz (with emtricitabine-tenofovir DF):

• Common (1% to 10%): Insomnia, abnormal dreams, depression, sleep disorder, nightmare, anxiety

Efavirenz:

• Very common (10% or more): Insomnia (16.3%)
• Common (1% to 10%): Severe depression, abnormal dreams, hallucinations
• Uncommon (0.1% to 1%): Suicidal ideation, nonfatal suicide attempts, aggressive behavior, paranoid reactions, manic reactions
• Postmarketing reports: Aggressive reactions, agitation, delusions, emotional lability, mania, neurosis, paranoia, psychosis, suicide, catatonia^[Ref]

Genitourinary

• Common (1% to 10%): Hematuria

Tenofovir DF:

• Postmarketing reports: Proteinuria, polyuria^[Ref]

Hematuria (greater than 100 RBC/high power field) has been reported in 7% of patients using efavirenz, lamivudine, and tenofovir DF.^[Ref]

Hepatic

• Common (1% to 10%): Elevated AST, elevated ALT

Efavirenz (with emtricitabine-tenofovir DF):

• Common (1% to 10%): ALT abnormal, AST abnormal
• Uncommon (0.1% to 1%): Bilirubin abnormal

Efavirenz:

• Postmarketing reports: Increased hepatic enzymes, hepatic failure, hepatitis (including fulminant hepatitis progressing to liver failure requiring transplantation or resulting in death)

Lamivudine:

• Postmarketing reports: Hepatic steatosis, posttreatment exacerbation of hepatitis B

Tenofovir DF:

• Postmarketing reports: Hepatic steatosis, hepatitis, increased liver enzymes (most commonly AST, ALT, GGT)

Combination antiretroviral therapy:

• Frequency not reported: Hepatic decompensation^[Ref]

Elevated AST (males: greater than 180 units/L; females: greater than 170 units/L) and ALT (males: greater than 215 units/L; females: greater than 170 units/L) have been reported in 5% and 4% patients using efavirenz, lamivudine, and tenofovir DF, respectively.

Lactic acidosis and severe hepatomegaly with steatosis (including fatal cases) have been reported with the use of nucleoside analogs.

Severe acute exacerbations of hepatitis B have been reported in patients coinfected with HIV-1 and hepatitis B virus after discontinuation of lamivudine or tenofovir DF.

Hepatic decompensation (some fatal) has been reported in patients coinfected with HIV-1 and hepatitis C receiving combination antiretroviral therapy for HIV-1 and interferon alfa with or without ribavirin.^[Ref]

Hematologic

• Common (1% to 10%): Decreased neutrophils

Efavirenz (with emtricitabine-tenofovir DF):

• Common (1% to 10%): Neutrophils abnormal

Lamivudine:

• Postmarketing reports: Anemia (including pure red cell aplasia and severe anemias progressing on therapy)^[Ref]

Decreased neutrophils (less than 750/mm3) has been reported in 3% of patients using efavirenz, lamivudine, and tenofovir DF.^[Ref]

Respiratory

• Common (1% to 10%): Pneumonia

Efavirenz (with emtricitabine-tenofovir DF):

• Common (1% to 10%): Upper respiratory tract infection, nasopharyngitis

Efavirenz:

• Postmarketing reports: Dyspnea

Tenofovir DF:

• Postmarketing reports: Dyspnea^[Ref]

Renal

Tenofovir DF:

• Postmarketing reports: Renal insufficiency, acute renal failure, renal failure, acute tubular necrosis, Fanconi syndrome, proximal renal tubulopathy, interstitial nephritis (including acute cases), nephrogenic diabetes insipidus, increased creatinine^[Ref]

Hypersensitivity

Efavirenz:

• Postmarketing reports: Allergic reactions

Lamivudine:

• Postmarketing reports: Anaphylaxis

Tenofovir DF:

• Postmarketing reports: Allergic reaction (including angioedema)^[Ref]

Cardiovascular

Efavirenz:

• Frequency not reported: QTc prolongation
• Postmarketing reports: Palpitations^[Ref]

Immunologic

• Frequency not reported: Immune reconstitution syndrome, autoimmune disorders in the setting of immune reconstitution (e.g., Graves' disease, polymyositis, Guillain-Barre syndrome)^[Ref]

Endocrine

• Frequency not reported: Higher serum parathyroid hormone levels

Efavirenz:

• Postmarketing reports: Gynecomastia^[Ref]

Ocular

Efavirenz:

• Postmarketing reports: Abnormal vision^[Ref]

See also:

Frequently asked questions

• What is the difference between HIV treatments Symfi and Symfi Lo?
• What drugs are contained in the HIV treatment Symfi Lo?

Further information

Symfi Lo side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer