Symfi Lo

Symfi Lo treats HIV. Do not skip any doses as this may make it more difficult to treat HIV.

Symfi Lo Overview

Reviewed: February 20, 2018

Symfi Lo is a prescription medication used as a complete regimen to treat human immunodeficiency virus type 1 (HIV-1) infection. It is a single product containing 3 medications: efavirenz, lamivudine and tenofovir disoproxilfumarate. 

Efavirenz belongs to a group of drugs called non-nucleoside reverse transcriptase inhibitors (NNRTIs), and lamivudine and tenofovir disoproxil fumarate are nucleotide reverse transcriptase inhibitors (NRTIs). These drugs work by preventing the virus from replicating.

This medication comes in tablet form and is taken once daily on an empty stomach, preferably at bedtime. 

Common side effects of Symfi Lo include rash and dizziness.

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Symfi Lo Cautionary Labels


Uses of Symfi Lo

Symfi Lo is a prescription medication used to treat human immunodeficiency virus type 1 (HIV-1) infection in adult and pediatric patients weighing at least 35 kg (77 pounds). 

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

Efavirenz & Lamivudine & Tenofovir disoproxil fumarate

For more information on this medication choose from the list of selections below.

Symfi Lo Drug Class

Side Effects of Symfi Lo

Serious side effects have been reported with Symfi Lo. See the “Symfi Lo Precautions” section.

Common side effects of Symfi Lo include the following:

  • Rash
  • Headache
  • Pain
  • Diarrhea
  • Nausea
  • Fever
  • Abdominal pain
  • Vomiting

This is not a complete list of Symfi Lo side effects. Ask your doctor or pharmacist for more information.

Tell your doctor if you have any side effects that bother you or that do not go away.

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

Symfi Lo Interactions

Tell your doctor about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:

  • Other antiretroviral medications such as:
  • Drugs that can cause an arrhythmia called Torsades des Point such as:

    • certain anti-arrhythmia medications including: procainamide, sotalol (Betapace), quinidine, dofetilide (Tikosyn), amiodarone (Nexterone, Pacerone, Cordarone), ibutilide (Corvert)
    • certain fluoroquinolone antibiotics including: levofloxacin (Levaquin), ciprofloxacin (Cipro), gatifloxacin (Zymar), moxifloxacin (Avelox)
    • certain macrolide antibiotics including: clarithromycin (Biaxin), erythromycin (EES, others)
    • certain azole antifungals including: ketoconazole (Nizoral), itraconazole (Sporanox, Onmel)
    • certain antidepressants including: amitriptyline, desipramine (Norpramin), imipramine (Tofranil), doxepin (Silenor), fluoxetine (Prozac, Sarafem, Symbyax), sertraline (Zoloft), venlafaxine (Effexor XR)
    • certain antipsychotics including: haloperidol (Haldol), droperidol (Inapsine), quetiapine (Seroquel XR), thioridazine, ziprasidone (Geodon)
    • and other medications including: cisapride, sumatriptan (Treximet, Imitrex, Alsuma, Zecuity), zolmitriptan (Zomig, arsenic trioxide (Trisenox), dolasetron (Anzemet), and methadone (Methadone, Dolophine)
  • Hepatitis C antiviral agents such as:
    • boceprevir (Victrelis)
    • elbasvir/grazoprevir (Zepatier)
    • pibrentasvir/glecaprevir (Mavyret)
    • simeprevir (Olysio)
    • velpatasvir/sofosbuvir (Epclusa)
    • velpatasvir/sofosbuvir/voxilaprevir (Vosevi)
    • ledipasvir/sofosbuvir (Harvoni)
  • Medications that reduce drug clearance through the kidneys such as acyclovir (Zovirax, adefovir dipivoxil (Hepsera), cidofovir (Vistide), ganciclovir (Cytovene), valacyclovir (Valtrex), valganciclovir (Valcyte), aminoglycosides, and high-dose or multiple NSAIDs
  • Medications that increase the activity of the enzyme CYP3A4 such as carbamazepine (Tegretol, Equetro, Carbatrol), phenobarbital, phenytoin (Dilantin), rifampin (Rifadin), and St John's wort
  • Antifungals such as itraconazole (Onmel, Sporanox), ketoconazole, and posaconazole (Noxafil)
  • Calcium channel blockers such as nifedipine (Adalat, Nifedical, Procardia), amlodipine (Norvasc), verapamil (Calan, Isoptin, Covera, Verelan), diltiazem (Cardizem)
  • Immunosuppressants such as cyclosporine (Gengraf, Neoral), sirolimus (Rapamune), and tacrolimus (Astagraf, Prograf)
  • HMG-CoA reductase inhibitors such as atorvastatin (Lipitor), pravastatin (Pravachol) and simvastatin (Zocor)
  • Hormonal contraceptives such as oral ethinyl estradiol/norgestimate and implant etonorgestrel
  • Bupropion (Wellbutrin)
  • Methadone (Dolophine)
  • Rifabutin (Mycobutin)
  • Rifampin (Rifadin)
  • Sertraline (Zoloft)

This is not a complete list of Symfi Lo drug interactions. Ask your doctor or pharmacist for more information.

Symfi Lo Precautions

Serious side effects have been reported with Symfi Lo including the following:

  • Severe acute exacerbation (flare-up) of hepatitis B. 
    • If you are also infected with the hepatitis B virus (HBV), you need medical exams and blood tests to check for HBV getting worse for several months after stopping treatment with Truvada. People with hepatitis B virus infection, who take Truvada and then stop it, may get "flare-ups" of their hepatitis. A "flare-up" is when the disease suddenly returns in a worse way than before.
  • Build up of acid in the blood (lactic acidosis). Tell your doctor right away if you get the following signs or symptoms of lactic acidosis:
    • extreme weakness or tiredness
    • unusual (not normal) muscle pain
    • trouble breathing
    • stomach pain with nausea (upset stomach) and vomiting
    • you feel cold, especially in your arms and legs
    • dizziness or lightheadedness
    • fast or irregular heartbeat
  • Liver problems. Tell your doctor right away if you get the following signs or symptoms of liver problems:
    • skin or the white part of your eyes turns yellow (jaundice)
    • urine (pee) turns dark
    • bowel movements (stools) turn light in color
    • you don't feel like eating food for several days or longer
    • you feel sick to your stomach (nausea)
    • you have lower stomach area (abdominal) pain
  • Kidney problems. Tell your doctor right away if you get the following signs or symptoms of kidney problems:
    • Change in urination habits
    • Swelling in your ankles or lower legs
    • Shortness of breath
    • Feeling more tired than normal
    • Muscle cramps or spasms
    • Loss of appetite
  • Psychiatric symptoms. Tell your doctor right away if you get the following psychiatric symptoms:
    • New or worsening depression
    • Suicidal thoughts
    • Aggressive behavior
  • Nervous system symptoms. Tell your doctor right away if you get the following signs or symptoms: 
    • dizziness
    • trouble sleeping
    • trouble concentrating
    • abnormal dreams
    • hallucinations
  • If you are pregnant, harm to your unborn baby. Talk to your doctor if you are taking Symfi Lo and are thinking about or planning to become pregnant.
  • Skin reactions and allergic reactions. Skin reactions or rash can happen and can sometimes be severe. Skin rash usually goes away without any change in treatment. If you develop a rash or a rash with any of the following symptoms, call your healthcare provider right away: 
    • itching
    • fever
    • swelling of your face
    • blisters or skin lesions
    • peeling skin
    • mouth sores
    • red or inflammed eyes 
  • Pancreatitis. Tell your doctor right away if you have the following signs or symptoms of pancreatitis:
    • abdominal pain that gets worse after eating
    • fever
    • nausea
    • vomiting
    • pain when touching the abdomen
    • losing weight without trying
    • oil, smelly stools
  • Seizures. Tell your doctor if you have any history of seizures or the following signs or symptoms of seizures:
    • having uncontrollable muscle spasms
    • drooling
    • clenching your teeth
    • biting your tongue
    • having sudden, fast eye movements
  • Increased blood fat (cholesterol and triglyceride) levels. Your doctor will check your blood fat levels before and during treatment with Symfi Lo.
  • Changes in your immune system. Tell your doctor right away if you start having any new symptoms after starting this medication.
  • Changes in body fat. This can happen in some people who take anti-HIV medications. These changes may include increased amount of fat in the upper back and neck, breast, and around the main part of your body. Loss of fat from the legs, arms, and face may also happen. The cause and long-term health effects of this is not known
  • Bone problems. This can happen in some people who take Symfi Lo. Bone problems include bone pain, softening or thinning (which may lead to fractures). Your doctor may need to do tests to check your bones. Tell your doctor if you have any bone pain, pain in your hands or feet, or muscle pain or weakness during treatment with Symfi Lo. 

Symfi Lo Food Interactions

Medications can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of Symfi Lo, there are no specific foods that you must exclude from your diet when receiving this medication.

Inform MD

Tell your doctor about all of your medical conditions. Especially tell your doctor if you:

  • have kidney, bone or liver problems (including hepatitis B infection). Be sure and tell your doctor if you are undergoing kidney dialysis treatment.
  • have a history of mental health problems
  • have a history of drug or alcohol abuse
  • have a heart problem, including QT prolongation
  • are pregnant or breastfeeding

Tell your doctor about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements. 

Symfi Lo and Pregnancy

Tell your doctor if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Symfi Lo falls into category D. It has been shown that use of Symfi Lo in pregnant women caused some babies to be born with problems. However, in some serious situations, the benefit of using this medication may be greater than the risk of harm to the baby.

If you use Symfi Lo while you are pregnant, talk to your doctor about how you can be on the Antiviral Pregnancy Registry.

Symfi Lo and Lactation

Tell your doctor if you are breastfeeding. You should not breastfeed if you are HIV-positive because of the chance of passing the HIV virus to your baby.

Also, it is not known if Symfi Lo can pass into your breast milk and if it can harm your baby. If you are a woman who has or will have a baby, talk with your doctor about the best way to feed your baby.

Symfi Lo Usage

Take Symfi Lo exactly as prescribed.

Symfi Lo comes in a tablet form and is taken once daily on an empty stomach, preferably at bedtime. You should take Symfi Lo at the same time each day, to help you to remember your dose.

If you miss a dose, take it as soon as you remember that day. Do not take 2 doses in one day. Do not skip doses.

If you stop taking Symfi Lo, even for a short time, the amount of virus in your blood may increase. The virus may become harder to treat. 

Symfi Lo should not be combined with any other anti-HIV medications. 

Symfi Lo Dosage

Take Symfi Lo exactly as prescribed by your doctor. Follow the directions on your prescription label carefully. Your doctor will determine the best dose for you.

For HIV-1 treatment, the dose of Symfi Lo for adults and children with body weight greater than or equal to 35 kg (greater than or equal to 77 lb) is one tablet (containing 400 mg efavirenz, 300 mg of lamivudine and 300 mg of tenofovir disoproxil fumarate), once daily, without food and preferably at bedtime.

Symfi Lo Overdose

If you take too much Symfi Lo, call your healthcare provider or local Poison Control Center, or seek emergency medical attention right away.

Other Requirements

Store Symfi Lo tablets below 86°F (30°C).

Keep Symfi Lo tablets in the original container.

Keep this and all medicines out of the reach of children.

Symfi Lo FDA Warning

Severe 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 Symfi Lo. Monitor hepatic function closely in these patients and, if appropriate, initiate anti-hepatitis B treatment.


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