Emtricitabine and Tenofovir Alafenamide
(em trye SYE ta been & ten OF oh vir al a FEN a mide)
- Emtricitabine and Tenofovir Alafenamide
- Emtricitabine/Tenofov Alafenam
- Tenofovir Alafenamide and Emtricitabine
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Descovy: Emtricitabine 200 mg and tenofovir alafenamide 25 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 alafenamide fumarate (TAF) is an analog of adenosine 5'-monophosphate. Each drug interferes with HIV viral RNA dependent DNA polymerase activities resulting in inhibition of viral replication.
Emtricitabine: Not significantly metabolized; TAF: Primarily intracellular metabolism; minimal extent by CYP3A
Emtricitabine: Urine (70%); feces (13.7%); TAF: Urine (<1%), feces 31.7%)
Clearance: Emtricitabine and tenofovir may be eliminated by both glomerular filtration and active tubular secretion
Emtricitabine: 10 hours; TAF: 0.51 hours
Emtricitabine: <4%; TAF: ~80%
Use: Labeled Indications
HIV-1 infection: Treatment of HIV-1 infection in combination with other antiretroviral agents in adults and pediatric patients weighing ≥35 kg; in combination with other antiretroviral agents (other than protease inhibitors that require a CYP3A inhibitor) in pediatric patients weighing ≥25 kg and <35 kg.
Limitations of use: Not indicated for use as preexposure prophylaxis (PrEP) to reduce the risk of sexually acquired HIV-1 in adults at high risk.
There are no contraindications listed in the manufacturer's US labeling.
Canadian labeling: Additional contraindications (not in US labeling): Hypersensitivity to emtricitabine, tenofovir alafenamide, or any component of the formulation.
HIV-1 infection: Oral: One tablet (emtricitabine 200 mg/tenofovir alafenamide 25 mg) once daily
Refer to adult dosing.
HIV-1 infection: Children and Adolescents ≥25 kg: Oral: Refer to adult dosing. Note: Safety and effectiveness of coadministration with an HIV-1 protease inhibitor administered with either ritonavir or cobicistat have not been established in pediatric patients weighing <35 kg.
Dosing: Renal Impairment
CrCl ≥30 mL/minute: No dosage adjustment necessary.
CrCl <30 mL/minute: Use is not recommended.
Dosing: Hepatic Impairment
Mild-to-moderate impairment (Child-Pugh class A or B): No dosage adjustment necessary.
Severe impairment (Child-Pugh class C): There are no dosage adjustments provided in the manufacturer's labeling (has not been studied).
Administer orally with or without food.
Store below 30°C (86°F). Dispense in original container.
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
Cabozantinib: MRP2 Inhibitors may increase the serum concentration of Cabozantinib. Monitor therapy
CarBAMazepine: May decrease the serum concentration of Tenofovir Alafenamide. Avoid combination
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
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
Fosphenytoin-Phenytoin: May decrease the serum concentration of Tenofovir Alafenamide. Avoid combination
Ganciclovir-Valganciclovir: Tenofovir Products may increase the serum concentration of Ganciclovir-Valganciclovir. Ganciclovir-Valganciclovir may increase the serum concentration of Tenofovir Products. Monitor therapy
LamiVUDine: May enhance the adverse/toxic effect of Emtricitabine. Avoid combination
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
OXcarbazepine: May decrease the serum concentration of Tenofovir Alafenamide. Avoid combination
PHENobarbital: May decrease the serum concentration of Tenofovir Alafenamide. Avoid combination
Primidone: May decrease the serum concentration of Tenofovir Alafenamide. Avoid combination
Rifabutin: May decrease the serum concentration of Tenofovir Alafenamide. Avoid combination
RifAMPin: May decrease the serum concentration of Tenofovir Alafenamide. Avoid combination
Rifapentine: May decrease the serum concentration of Tenofovir Alafenamide. Avoid combination
St John's Wort: May decrease the serum concentration of Tenofovir Alafenamide. Avoid combination
Tipranavir: May decrease the serum concentration of Tenofovir Alafenamide. Avoid combination
All adverse drug reactions are from combination therapy with cobistat plus elvitegravir in treatment-naïve and treatment-experienced patients. Also see individual agents.
1% to 10%:
Gastrointestinal: Nausea (10%)
Neuromuscular & skeletal: Decreased bone mineral density (≥5% decrease at lumbar spine: 1% to 10%; ≥7% decrease at femoral neck: 1% to 7%), bone fracture (≤1%; excluding fingers and toes)
Frequency not defined:
Endocrine & metabolic: Increased HDL cholesterol, increased LDL cholesterol, increased serum cholesterol, increased serum triglycerides
Hepatic: Exacerbation of hepatitis B
Renal: Increased serum creatinine (mean increase 0.1 mg/dL)
<1% (Limited to important or life-threatening): Acute renal failure, renal disease
Concerns related to adverse effects:
• 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: Lactic acidosis and severe hepatomegaly with steatosis, sometimes fatal, have been reported with use of nucleoside analogues, alone or in combination with other antiretrovirals. Suspend treatment in any patient who develops clinical or laboratory findings suggestive of lactic acidosis or pronounced hepatotoxicity (marked transaminase elevation may/may not accompany hepatomegaly and steatosis).
• Renal toxicity: Cases of acute renal failure and/or Fanconi syndrome have been reported with use of tenofovir prodrugs; patients with preexisting renal impairment and those taking nephrotoxic agents (including NSAIDs) are at increased risk. Assess estimated creatinine clearance, urine protein, and urine glucose prior to initiation of therapy and during therapy. Monitor serum phosphorus in patients with chronic kidney disease (increased risk of developing Fanconi syndrome). Discontinue therapy in patients that develop clinically significant decreases in renal function or evidence of Fanconi syndrome.
• Chronic hepatitis B: [US Boxed Warning]: Safety and efficacy during coinfection of HIV-1 and HBV have not been established; acute, severe exacerbations of HBV have been reported following discontinuation of antiretroviral therapy. Not indicated for treatment of chronic hepatitis B. Closely monitor hepatic function with clinical and laboratory follow-up for at least several months in patients who are coinfected with HIV-1 and HBV and discontinue this therapy. If appropriate, antihepatitis B therapy may be warranted, especially in patients with advanced hepatic disease or cirrhosis (post-treatment HBV exacerbations may lead to hepatic decompensation and liver failure). All patients with HIV should be tested for HBV prior to initiation of treatment.
• Renal impairment: Use is not recommended in patients with CrCl <30 mL/minute.
Concurrent drug therapy issues:
• 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.
CD4 count, HIV RNA plasma levels; serum creatinine, urine glucose, urine protein (prior to initiation and as clinically indicated during therapy); serum phosphorus (in patients with chronic kidney disease); hepatic function tests, BMD (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. Patients with HIV and HBV coinfection should be monitored for several months following therapy discontinuation.
The Health and Human Services (HHS) Perinatal HIV Guidelines note there are insufficient data to recommend use of this combination product as an initial regimen in antiretroviral-naive pregnant women. In general, women who become pregnant on a stable cART regimen may continue that regimen if viral suppression is effective, appropriate drug exposure can be achieved, contraindications for use in pregnancy are not present, and the regimen is well tolerated. Monitoring during pregnancy is more frequent than in non-pregnant adults; cART should be continued postpartum (HHS [perinatal] 2016). Refer to individual monographs.
• 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. Have patient report immediately to prescriber signs of infection, signs of kidney problems (urinary retention, hematuria, change in amount of urine passed, or weight gain), signs of liver problems (dark urine, fatigue, lack of appetite, nausea, abdominal pain, light-colored stools, vomiting, or jaundice), signs of lactic acidosis (fast breathing, tachycardia, abnormal heartbeat, vomiting, fatigue, shortness of breath, severe loss of strength and energy, or severe dizziness, feeling cold, or muscle pain or cramps) (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 health care 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.