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SYMFI LO™ (efavirenz, lamivudine and tenofovir disoproxil fumarate) is indicated as a complete regimen for the treatment of human immunodeficiency virus type 1 (HIV-1) infection in adult and pediatric patients weighing at least 35 kg.


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 [see Warnings and Precautions (5.2)].


SYMFI LO is contraindicated:
  • in patients with a previous hypersensitivity reaction (e.g., Stevens-Johnson syndrome, erythema multiforme, or toxic skin eruptions) to any of the components contained in the formulation.
  • when coadministered with elbasvir and grazoprevir

Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, have been reported with the use of nucleoside analogs and other antiretrovirals. Treatment should be suspended in any patient who develops clinical or laboratory findings suggestive of lactic acidosis or pronounced hepatotoxicity (which may include hepatomegaly and steatosis even in the absence of marked transaminase elevations).

All patients with HIV-1 should be tested for the presence of chronic hepatitis B virus (HBV) before initiating antiretroviral therapy. Discontinuation of anti-HBV therapy, including lamivudine (3TC) and tenofovir disoproxil fumarate (TDF), may be associated with severe acute exacerbations of hepatitis. Patients infected with HBV who discontinue SYMFI LO should be closely monitored with both clinical and laboratory follow-up for at least several months after stopping treatment. If appropriate, resumption of anti-hepatitis B therapy may be warranted. See the full prescribing information for Important Differences Among Lamivudine-Containing Products

The concomitant use of SYMFI LO and other drugs may result in known or potentially significant drug interactions, some of which may lead to loss of therapeutic effect of SYMFI LO and possible development of resistance or possible clinically significant adverse reactions from greater exposures of concomitant drugs. See Table 5 for steps to prevent or manage these possible and known significant drug interactions, including dosing recommendations

TDF, a component of SYMFI LO is principally eliminated by the kidney. Renal impairment, including cases of acute renal failure and Fanconi syndrome (renal tubular injury with severe hypophosphatemia), has been reported with the use of TDF.

It is recommended that estimated creatinine clearance be assessed in all patients prior to initiating therapy and as clinically appropriate during therapy with TDF. In patients at risk of renal dysfunction, it is recommended that estimated creatinine clearance, serum phosphorus, urine glucose, and urine protein be assessed prior to initiation of TDF, and periodically during TDF therapy.

SYMFI LO should be avoided with concurrent or recent use of a nephrotoxic agent (e.g., high-dose or multiple non-steroidal anti-inflammatory drugs (NSAIDs)).

Persistent or worsening bone pain, pain in extremities, fractures and/or muscular pain or weakness may be manifestations of proximal renal tubulopathy and should prompt an evaluation of renal function in at-risk patients.

Serious psychiatric adverse experiences have been reported in patients treated with efavirenz (EFV), a component of SYMFI LO. In controlled trials in patients treated with regimens containing EFV the following serious psychiatric events occurred: severe depression, suicidal ideation, nonfatal suicide attempts, aggressive behavior, paranoid reactions, and manic reactions. When psychiatric symptoms similar to those noted above were combined and evaluated as a group in a multifactorial analysis of data from a study using EFV 600 mg, treatment with EFV was associated with an increase in the occurrence of these selected psychiatric symptoms. See full prescribing information for other factors associated with an increase in the occurrence of psychiatric symptoms.

Patients receiving EFV, a component of SYMFI LO, in controlled trials reported central nervous system symptoms. These symptoms included, but were not limited to, dizziness, insomnia, impaired concentration, somnolence, abnormal dreams, and hallucinations. In some cases, the symptoms were severe. Patients should be informed that these common symptoms usually begin during the first or second day of therapy and were likely to improve with continued therapy and were not predictive of subsequent onset of the less frequent psychiatric symptoms.

EFV, a component of SYMFI LO, may cause fetal harm when administered during the first trimester to a pregnant woman. Females of reproductive potential who are receiving EFV should avoid pregnancy.

In controlled clinical trials, patients treated with 600 mg EFV experienced new-onset skin rash associated with blistering, moist desquamation, or ulceration.

EFV should be discontinued in patients developing severe rash associated with blistering, desquamation, mucosal involvement, or fever. EFV can generally be reinitiated in patients interrupting therapy because of rash.

EFV, a component of SYMFI LO, is not recommended for patients with moderate or severe hepatic impairment. Careful monitoring is recommended for patients with mild hepatic impairment receiving EFV.

Monitoring of liver enzymes before and during treatment is recommended for all patients. Consider discontinuing SYMFI LO in patients with persistent elevations of serum transaminases to greater than five times the upper limit of the normal range.

Discontinue SYMFI LO if elevation of serum transaminases is accompanied by clinical signs or symptoms of hepatitis or hepatic decompensation.

In vitro studies have shown ribavirin can reduce the phosphorylation of pyrimidine nucleoside analogues such as 3TC, a component of SYMFI LO. Although no evidence of a pharmacokinetic or pharmacodynamic interaction (e.g., loss of HIV-1/HCV virologic suppression) was seen when ribavirin was coadministered with 3TC in HIV-1/HCV co-infected patients, hepatic decompensation (some fatal) has occurred in HIV-1/HCV co-infected patients receiving combination antiretroviral therapy for HIV-1 and interferon alfa with or without ribavirin. Patients receiving interferon alfa with or without ribavirin and 3TC should be closely monitored for treatment-associated toxicities, especially hepatic decompensation. See the full prescribing information for interferon and ribavirin.

In pediatric patients with a history of prior antiretroviral nucleoside exposure, a history of pancreatitis, or other significant risk factors for the development of pancreatitis, 3TC, a component of SYMFI LO, should be used with caution. Treatment with SYMFI LO should be stopped immediately if clinical signs, symptoms, or laboratory abnormalities suggestive of pancreatitis occur

Convulsions have been observed in patients receiving EFV, generally in the presence of known medical history of seizures. Caution should be taken in any patient with a history of seizures. Patients who are receiving concomitant anticonvulsant medications primarily metabolized by the liver, such as phenytoin and phenobarbital, may require periodic monitoring of plasma levels

Treatment with EFV has resulted in increases in the concentration of total cholesterol and triglycerides. Cholesterol and triglyceride testing should be performed before initiating EFV therapy and at periodic intervals during therapy.

In clinical trials in HIV-1 infected adults, TDF was associated with slightly greater decreases in bone mineral density (BMD) and increases in biochemical markers of bone metabolism, suggesting increased bone turnover relative to comparators. Serum parathyroid hormone levels and 1,25 Vitamin D levels were also higher in subjects receiving TDF. The effects of TDF-associated changes in BMD and biochemical markers on long-term bone health and future fracture risk are unknown.

Cases of osteomalacia associated with proximal renal tubulopathy, manifested as bone pain or pain in extremities and which may contribute to fractures, have been reported in association with the use of TDF.

Autoimmune disorders (such as Graves’ disease, polymyositis, and Guillain-Barre syndrome) have also been reported to occur in the setting of immune reconstitution in patients treated with combination antiretroviral therapy, including EFV, 3TC, and TDF.

In HIV-infected patients, redistribution/accumulation of body fat including central obesity, dorsocervical fat enlargement (buffalo hump), peripheral wasting, facial wasting, breast enlargement, and “cushingoid appearance” have been observed in patients receiving combination antiretroviral therapy.

QTc prolongation has been observed with the use of EFV.

Most common adverse reactions (> 5% with SYMFI LO components) are rash and dizziness.

Click here for Full Prescribing Information, including Boxed WARNING.

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