Emtricitabine and Tenofovir Disoproxil Fumarate
(em trye SYE ta been & ten OF oh vir dye soe PROX il FUE ma rate)
- Tenofovir Disoproxil Fumarate and Emtricitabine
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Truvada: Emtricitabine 100 mg and tenofovir disoproxil fumarate 150 mg, Emtricitabine 133 mg and tenofovir disoproxil fumarate 200 mg, Emtricitabine 167 mg and tenofovir disoproxil fumarate 250 mg, Emtricitabine 200 mg and tenofovir disoproxil fumarate 300 mg [contains fd&c blue #2 aluminum lake]
Brand Names: U.S.
- Antiretroviral, Reverse Transcriptase Inhibitor, Nucleoside (Anti-HIV)
- Antiretroviral, Reverse Transcriptase Inhibitor, Nucleotide (Anti-HIV)
Nucleoside and nucleotide reverse transcriptase inhibitor combination; emtricitabine is a cytosine analogue while tenofovir is an analog of adenosine 5'-monophosphate. Each drug interferes with HIV viral RNA dependent DNA polymerase resulting in inhibition of viral replication.
Use: Labeled Indications
HIV-1 infection, treatment: Treatment of HIV-1 infection in combination with other antiretroviral agents in adults and pediatric patients weighing ≥17 kg (US labeling) or in adult patients (Canadian labeling)
HIV-1 infection, prophylaxis: Pre-exposure prophylaxis (PrEP) for prevention of HIV-1 infection in adults who are at high risk for acquiring HIV
Treatment of hepatitis B in patients with antiviral-resistant HBV or coinfection with HIV; pre-exposure prophylaxis (PrEP) for prevention of HIV-1 infection in injecting drug users (IDU) who are at risk for parenteral acquisition of HIV but not at risk for sexual acquisition of HIV; postexposure prophylaxis (PEP) for occupational exposure to HIV
Do not use for preexposure prophylaxis in patients with unknown or HIV-1 positive status. For HIV-1 treatment, use only in HIV-1-infected patients in combination with other antiretrovirals.
Canadian labeling: Additional contraindications (not in US labeling): Previously demonstrated hypersensitivity to any component of the formulation.
Note: Avoid concurrent use with adefovir or lamivudine-containing products or other emtricitabine- and/or tenofovir-containing products.
HIV-1 infection: Oral: One tablet (emtricitabine 200 mg and tenofovir 300 mg) once daily in combination with other antiretroviral agents. Note: Emtricitabine and tenofovir is a component of recommended initial regimens in all treatment-naive patients (coadministered with dolutegravir, with raltegravir, or with darunavir/ritonavir), and is a component of a recommended initial regimen only for treatment-naive adolescent and adult patients with pre-ART CrCl >70 mL/minute (coadministered with elvitegravir/cobicistat) (HHS [adult] 2015).
Preexposure prophylaxis (PrEP) for prevention of HIV infection in uninfected high-risk individuals: Oral: One tablet (emtricitabine 200 mg and tenofovir 300 mg) once daily
Hepatitis B treatment in patients with antiviral-resistant HBV or coinfection with HIV (off-label use): Oral: One tablet (emtricitabine 200 mg and tenofovir 300 mg) once daily (Lok 2009)
Occupational HIV postexposure, prophylaxis (PEP) (off-label use): Oral: One tablet (emtricitabine 200 mg and tenofovir 300 mg) once daily for 4 weeks with concomitant raltegravir. Recommended as preferred therapy (Kuhar 2013)
PrEP for prevention of HIV infection in injecting drug users (IDU) who are at risk for parenteral acquisition of HIV but not at risk for sexual acquisition of HIV (off-label use): Oral: One tablet (emtricitabine 200 mg and tenofovir 300 mg) once daily (CDC 2013)
Refer to adult dosing.
HIV-1 infection: Note: Use only in combination with other antiretroviral agents.
Children and Adolescents 17 to <22 kg: Oral: One tablet (emtricitabine 100 mg/tenofovir 150 mg) once daily
Children and Adolescents 22 to <28 kg: Oral: One tablet (emtricitabine 133 mg/tenofovir 200 mg) once daily
Children and Adolescents 28 to <35 kg: Oral: One tablet (emtricitabine 167 mg/tenofovir 250 mg) once daily
Children and Adolescents ≥35 kg: Oral: Refer to adult dosing.
Canadian labeling: Use is not approved in pediatric patients.
Dosing: Renal Impairment
HIV-1 infection: Adults:
CrCl ≥50 mL/minute: No dosage adjustment necessary
CrCl 30 to 49 mL/minute: Increase interval to every 48 hours.
CrCl <30 mL/minute: Not recommended.
Hemodialysis: Not recommended.
Alternate recommendations (IDSA [Lucas 2014]): CrCl <50 mL/minute (and not on hemodialysis) or GFR <60 mL/minute/1.73 m2: Avoid use of tenofovir
CrCl ≥60 mL/minute: No dosage adjustment necessary
CrCl <60 mL/minute: Not recommended.
Dosing: Hepatic Impairment
No dosing adjustment necessary for tenofovir in moderate to severe hepatic impairment; no specific data available on emtricitabine in hepatic impairment, but given limited hepatic metabolism, dose adjustments are unlikely.
Oral: May be administered with or without food.
May be taken without regard to meals. Consider calcium and vitamin D supplementation in patients with history of bone fracture or osteopenia.
Store tablets at 25°C (77°F); excursions permitted to 15°C to 30°C (59°F to 86°F). Dispense only in original container; do not use if seal on bottle is broken or missing.
Acyclovir-Valacyclovir: May increase the serum concentration of Tenofovir Products. Tenofovir Products may increase the serum concentration of Acyclovir-Valacyclovir. Monitor therapy
Adefovir: May diminish the therapeutic effect of Tenofovir Products. Adefovir may increase the serum concentration of Tenofovir Products. Tenofovir Products may increase the serum concentration of Adefovir. Avoid combination
Aminoglycosides: May increase the serum concentration of Tenofovir Products. Tenofovir Products may increase the serum concentration of Aminoglycosides. Monitor therapy
Atazanavir: Tenofovir Disoproxil Fumarate may decrease the serum concentration of Atazanavir. Atazanavir may increase the serum concentration of Tenofovir Disoproxil Fumarate. Management: Must use ritonavir-boosting in adults; give combo (atazanavir/ritonavir 300mg/100mg and tenofovir 300mg) as a single daily dose with food. Pediatric patients, pregnant patients, and users of H2-blockers require other dose changes. Consider therapy modification
Cabozantinib: MRP2 Inhibitors may increase the serum concentration of Cabozantinib. Monitor therapy
Cidofovir: May increase the serum concentration of Tenofovir Products. Tenofovir Products may increase the serum concentration of Cidofovir. Monitor therapy
Cobicistat: May enhance the adverse/toxic effect of Tenofovir Products. More specifically, cobicistat may impair proper tenofovir monitoring and dosing. Monitor therapy
Darunavir: Tenofovir Disoproxil Fumarate may increase the serum concentration of Darunavir. Darunavir may increase the serum concentration of Tenofovir Disoproxil Fumarate. Monitor therapy
Diclofenac (Systemic): May enhance the nephrotoxic effect of Tenofovir Products. Management: Seek alternatives to this combination whenever possible. Avoid use of tenofovir with multiple NSAIDs or any NSAID given at a high dose. Consider therapy modification
Didanosine: Tenofovir Disoproxil Fumarate may diminish the therapeutic effect of Didanosine. Tenofovir Disoproxil Fumarate may increase the serum concentration of Didanosine. Management: Avoid concomitant treatment with tenofovir disoproxil fumarate and didanosine. Consider altering even existing, stable treatment to avoid this combination. Avoid combination
Ganciclovir-Valganciclovir: May enhance the adverse/toxic effect of Reverse Transcriptase Inhibitors (Nucleoside). Hematologic toxicity with zidovudine is of particular concern. Ganciclovir-Valganciclovir may increase the serum concentration of Reverse Transcriptase Inhibitors (Nucleoside). Management: Monitor patients receiving any of these combination closely for toxicity of the reverse transcriptase inhibitor. Avoid zidovudine. Intravitreal implants would not be affected. Consider therapy modification
LamiVUDine: May enhance the adverse/toxic effect of Emtricitabine. Avoid combination
Ledipasvir: May increase the serum concentration of Tenofovir Disoproxil Fumarate. Management: Avoidance of this combination is recommended under some circumstances. Refer to full monograph for details. Consider therapy modification
Lopinavir: May enhance the nephrotoxic effect of Tenofovir Disoproxil Fumarate. Lopinavir may increase the serum concentration of Tenofovir Disoproxil Fumarate. Monitor therapy
Nonsteroidal Anti-Inflammatory Agents: May enhance the nephrotoxic effect of Tenofovir Products. Management: Seek alternatives to these combinations whenever possible. Avoid use of tenofovir with multiple NSAIDs or any NSAID given at a high dose. Consider therapy modification
Orlistat: May decrease the serum concentration of Antiretroviral Agents. Monitor therapy
Ribavirin (Oral Inhalation): May enhance the hepatotoxic effect of Reverse Transcriptase Inhibitors (Nucleoside). Monitor therapy
Ribavirin (Systemic): May enhance the hepatotoxic effect of Reverse Transcriptase Inhibitors (Nucleoside). Monitor therapy
Simeprevir: Tenofovir Disoproxil Fumarate may decrease the serum concentration of Simeprevir. Simeprevir may increase the serum concentration of Tenofovir Disoproxil Fumarate. Monitor therapy
Telaprevir: May increase the serum concentration of Tenofovir Disoproxil Fumarate. Monitor therapy
Tipranavir: Tenofovir Disoproxil Fumarate may decrease the serum concentration of Tipranavir. Tipranavir may decrease the serum concentration of Tenofovir Disoproxil Fumarate. Monitor therapy
TiZANidine: CYP1A2 Inhibitors (Weak) may increase the serum concentration of TiZANidine. Management: Avoid these combinations when possible. If combined use cannot be avoided, initiate tizanidine at an adult dose of 2 mg and increase in 2-4 mg increments based on patient response. Monitor for increased effects of tizanidine, including adverse reactions. Consider therapy modification
Velpatasvir: May increase the serum concentration of Tenofovir Disoproxil Fumarate. Monitor therapy
The adverse reaction profile of combination therapy has not been established. See individual agents.
Concerns related to adverse effects:
• Decreased bone mineral density: In clinical trials, tenofovir has been associated with decreases in bone mineral density in HIV-1 infected adults and increases in bone metabolism markers. Serum parathyroid hormone and 1,25 vitamin D levels were also higher. Decreases in bone mineral density have also been observed in clinical trials of HIV-1 infected pediatric patients. Observations in chronic hepatitis B infected pediatric patients (aged 12-18 years) were similar. In all pediatric clinical trials, skeletal growth (height) appears unaffected. Consider monitoring of bone density in adult and pediatric patients with a history of pathologic fractures or with other risk factors for bone loss or osteoporosis. Consider calcium and vitamin D supplementation for all patients; effect of supplementation has not been studied but may be beneficial. Long-term bone health and fracture risk unknown. If abnormalities are suspected, expert assessment is recommended.
• Fat redistribution: May cause redistribution of fat (eg, buffalo hump, peripheral wasting with increased abdominal girth, cushingoid appearance).
• Immune reconstitution syndrome: Patients may develop immune reconstitution syndrome resulting in the occurrence of an inflammatory response to an indolent or residual opportunistic infection during initial HIV treatment or activation of autoimmune disorders (eg, Graves’ disease, polymyositis, Guillain-Barré syndrome) later in therapy; further evaluation and treatment may be required.
• Lactic acidosis/hepatomegaly: [U.S Boxed Warning]: Lactic acidosis and severe hepatomegaly with steatosis have been reported with nucleoside and nucleotide analogues (eg, tenofovir), including fatal cases; use with caution in patients with risk factors for liver disease (risk may be increased with female gender, obesity, or prolonged exposure) and suspend treatment in any patient who develops clinical or laboratory findings suggestive of lactic acidosis or hepatotoxicity (transaminase elevation may/may not accompany hepatomegaly and steatosis).
• Osteomalacia and renal dysfunction: May cause osteomalacia with proximal renal tubulopathy. Bone pain, extremity pain, fractures, arthralgias, weakness and muscle pain have been reported. In patients at risk for renal dysfunction, persistent or worsening bone or muscle symptoms should be evaluated for hypophosphatemia and osteomalacia.
• Pancreatitis: Pancreatitis has been reported with combination regimens that contained tenofovir disoproxil fumarate; use with caution in patients with a prior history or risk factors for pancreatitis. Discontinue if pancreatitis is suspected.
• Renal toxicity: May cause renal toxicity (acute renal failure and/or Fanconi syndrome); avoid use with concurrent or recent nephrotoxic therapy (including high dose or multiple NSAID use). Acute renal failure has occurred in HIV-infected patients with risk factors for renal impairment who were on a stable tenofovir regimen to which a high dose or multiple NSAID therapy was added. Consider alternatives to NSAIDS in patients taking tenofovir and at risk for renal impairment. Calculate creatinine clearance prior to initiation of therapy and monitor renal function (including recalculation of creatinine clearance and serum phosphorus) during therapy. In patients at risk for renal dysfunction, including patients who have experienced renal events while taking adefovir, assess serum phosphorus, urine glucose, and urine protein prior to and periodically during treatment. Dosage adjustment required in patients with CrCl <50 mL/minute. Use with caution in patients with low body weight, or concurrent medications which increase tenofovir levels. IDSA guidelines recommend discontinuing tenofovir (and substituting with alternative antiretroviral therapy) in HIV-infected patients who develop a decline in GFR (a >25% decrease in GFR from baseline and to a level of <60 mL/minute/1.73 m2) during use, particularly in presence of proximal tubular dysfunction (eg, euglycemic glycosuria, increased urinary phosphorus excretion and hypophosphatemia, proteinuria [new onset or worsening]) (IDSA [Lucas 2014]).
• Chronic hepatitis B: [US Boxed Warning]: Safety and efficacy during coinfection of HIV and HBV have not been established; acute, severe exacerbations of HBV have been reported following discontinuation of antiretroviral therapy. Not approved for the treatment of chronic hepatitis B virus infection. All patients with HIV should be tested for HBV prior to initiation of treatment. Caution in patients with known or suspected hepatitis B or C infection (monitoring of liver function is recommended). In HBV coinfected patients, acute HBV infection exacerbations have occurred following discontinuation; monitor hepatic function closely for several months following discontinuation. If appropriate, antihepatitis B treatment may be warranted.
• Comprehensive prevention program: Preexposure prophylaxis (PrEP) should be accompanied by a comprehensive HIV-1 prevention program (eg, risk reduction counseling, access to condoms), with particular emphasis on medication adherence. In addition, regular monitoring (eg, HIV status of patient and partner(s), risk behavior, adherence, adverse effects, sexually transmitted infections that facilitate HIV-1 transmission) is highly recommended.
• Hepatic impairment: Use with caution in patients with hepatic impairment. No dosage adjustment is required; limited studies indicate the pharmacokinetics of tenofovir are not altered in hepatic dysfunction and emtricitabine is not significantly metabolized by liver enzymes, so the impact of liver impairment should be limited.
• HIV treatment: Appropriate use: Not recommended as a component of a triple nucleoside regimen due to potential for early virological failure. Clinical trials in HIV-infected patients whose regimens contained only three nucleoside reverse transcriptase inhibitors (NRTI) show less efficacy, early virologic failure and high rates of resistance substitutions. Triple drug regimens with two NRTIs in combination with a non-nucleoside reverse transcriptase inhibitor or a HIV-1 protease inhibitor are usually more effective.
• HIV treatment and renal impairment: Use with caution in patients with renal impairment (CrCl <50 mL/minute); dosage adjustment required. Closely monitor renal function and assess serum phosphorus, urine glucose, and urine protein prior to and periodically during treatment. Do not use in patients with CrCl <30 mL/minute or requiring hemodialysis. IDSA guidelines recommend avoiding tenofovir in HIV patients with preexisting kidney disease (CrCl <50 mL/minute and not on hemodialysis or GFR <60 mL/minute/1.73 m2) when other effective HIV treatment options exist because data suggest risk of chronic kidney disease (CKD) is increased (IDSA [Lucas 2014]).
• PrEP and renal impairment: Routinely monitor serum phosphorus, urine glucose, and urine protein prior to and periodically during treatment in patients with mild renal impairment. Calculate creatinine clearance prior to initiation in all patients; monitor renal function during therapy (including recalculation of creatinine clearance and serum phosphorus). Do not use in CrCl <60 mL/minute.
• Resistance risk with PrEP: [US Boxed Warning]: Confirm HIV-1 negative status immediately before and at least every 3 months during therapy. Risk of drug resistant HIV-1 variants with PrEP use if patient had undetected acute HIV-1 infection. Some HIV-1 tests (eg, rapid tests) do not detect acute HIV-1 infection. Screen PrEP candidates for acute viral infections and potential exposure events ≤1 month of starting PrEP. If infections or events exist, wait 1 month to start PrEP and reconfirm HIV-1 negative status. Do not start or continue PrEP if signs or symptoms of acute HIV-1 infection are present unless HIV-1 negative status is confirmed by a test approved by the Food and Drug Administration (FDA) as an aid to detect HIV-1 infection (including acute or primary infection).
Concurrent drug therapy issues:
• Adefovir: Do not use concurrently with adefovir.
• Drug-drug interactions: Potentially significant interactions may exist, requiring dose or frequency adjustment, additional monitoring, and/or selection of alternative therapy. Consult drug interactions database for more detailed information.
• Duplicate therapy: Do not use concurrently with emtricitabine, tenofovir, or any combination of these drugs.
• Lamivudine: Do not use concurrently with lamivudine or lamivudine-combination products.
CBC with differential, reticulocyte count, creatine kinase, CD4 count, HIV RNA plasma levels, serum phosphorus; serum creatinine (prior to initiation and as clinically indicated during therapy), urine glucose and urine protein (in patients with mild renal impairment [CrCl 30-49 mL/minute], at risk for renal impairment or who experienced renal impairment while taking adefovir), hepatic function tests, bone density (patients with a history of bone fracture or have risk factors for bone loss); testing for HBV is recommended prior to the initiation of antiretroviral therapy; weight (children).
Patients with HIV and HBV coinfection should be monitored for several months following tenofovir discontinuation.
HIV-1 preexposure prophylaxis (PrEP) (CDC 2011; CDC 2012): Pregnancy test for women receiving PrEP (every visit); documented negative HIV test (immediately prior to use, every 2-3 months, and following discontinuation of PrEP), assess risk behaviors and symptoms of sexually-transmitted infections (STIs) or acute HIV-1 infection and provide condoms (immediately prior to use, then every 2-3 months during therapy); BUN and serum creatinine (prior to initiation, 3 months after initiation, then every 6 months); urine glucose and urine protein (in patients at risk for renal impairment or who experienced renal impairment while taking adefovir); testing for HBV (prior to initiation) and STIs (prior to initiation, then at least every 6 months, even if asymptomatic)
HIV occupational postexposure prophylaxis (PEP) (Kuhar 2013): Documented HIV test (at baseline and 6 weeks, 12 weeks and 6 months after exposure); if confirmation that a fourth generation HIV p2 antigen-HIV antibody test is being used, monitor at baseline, 6 weeks and 4 months after exposure. CBC, renal and hepatic function assessments at baseline and 2 weeks after exposure (minimum recommendations, others dictated by clinical assessment)
Pregnancy Risk Factor
Animal reproduction studies have not been conducted with this combination. Refer to individual monographs.
An increased risk of birth defects has not been observed following use of this combination for pre-exposure prophylaxis (PrEP); pregnancy is not a contraindication to PrEP. The HHS Perinatal HIV Guidelines consider emtricitabine in combination with tenofovir to be a preferred NRTI backbone for use in antiretroviral-naive pregnant women (HHS [perinatal] 2016).
• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)
• Patient may experience nausea, diarrhea, insomnia, dizziness, headache, nightmares, or loss of strength and energy. Have patient report immediately to prescriber signs of too much lactic acid in the blood (lactic acidosis; fast breathing, fast heartbeat, abnormal heartbeat, vomiting, drowsiness, shortness of breath, feeling very tired or weak, severe dizziness, feeling cold, or muscle pain or cramps), signs of liver problems (dark urine, feeling tired, lack of appetite, nausea, abdominal pain, light-colored stools, vomiting, or yellow skin or eyes), signs of kidney problems (urinary retention, blood in urine, change in amount of urine passed, weight gain), depression, bone pain, muscle pain, painful extremities, change in body fat, burning or numbness feeling, or signs of infection (HCAHPS).
• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.
Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for healthcare professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience and judgment in diagnosing, treating and advising patients.
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