Dosing & Uses
Dosage Forms & Strengths
emtricitabine/tenofovir alafenamide (AF)
tablet
- 200mg/25mg
HIV Infection Treatment
Indicated in combination with other antiretroviral agents (ARTs) for treatment of HIV-1 infection in adults
200 mg/25 mg PO qDay
HIV-1 Pre-exposure Prophylaxis
Indicated for at-risk patients to reduce risk of HIV-1 infection from sex, excluding those at risk from receptive vaginal sex
200 mg/25 mg PO qDay
Dosage Modifications
Renal impairment
- Mild-to-moderate (CrCl ≥30 mL/min): No dosage adjustment required
- Severe (CrCl 15 to <30 mL/min): Not recommended
-
CrCl ≤15 mL/min
- Receiving chronic hemodialysis: On days of hemodialysis, administer daily dose after hemodialysis completion
- Not receiving chronic hemodialysis: Not recommended
- Coadministration of HIV-1 protease inhibitor (ie, ritonavir, cobicistat) with or without hemodialysis: Safety and efficacy not established
Hepatic impairment
- Mild-to-moderate (Child Pugh class A or B): No dosage adjustment required
- Severe (Child Pugh class C): Not studied
Dosing Considerations
For specific dosing recommendations for coadministered third agents for HIV treatment, refer to their respective prescribing information or AIDSinfo guidelines
HIV-1 screening for for HIV-1 PrEP
- Screen for HIV-1 infection immediately before initiating for HIV-1 PrEP and at least once q3Months during treatment, and upon diagnosis of any other sexually transmitted infections (STIs)
- If recent (<1 month) exposure to HIV-1 are suspected or clinical symptoms consistent with acute HIV-1 infection are present, use a test approved or cleared by the FDA to aid in the diagnosis of acute or primary HIV-1 infection
Laboratory testing
- Must have negative HIV-1 test immediately before initiating drug for HIV-1 PrEP
- Test for hepatitis B virus infection before initiating for HIV treatment or PrEP
- Assess estimated CrCl, urine glucose and urine protein before initiating therapy and monitor during therapy in all patients
Limitation of use
- Indication for PrEP does not include use in individuals at risk of HIV-1 from receptive vaginal sex
- Effectiveness in this population has not been evaluated
Dosage Forms & Strengths
emtricitabine/tenofovir alafenamide (AF)
tablet
- 200mg/25mg
- 120mg/15mg
HIV Infection Treatment
In combination with ARTs
- Indicated in combination with other antiretroviral agents (ARTs) for treatment of HIV-1 infection in pediatric patients who weigh ≥35 kg
- ≥35 kg: 200 mg/25 mg PO qDay
In combination with ARTs other than PIs requiring a CYP3A inhibitor
- Indicated in combination with other ARTs other than protease inhibitors (PI) requiring a CYP3A inhibitor, in pediatric patients weighing 14 to <35 kg
- Safety and efficacy of emtricitabine/tenofovir AF coadministered with an HIV-1 PI that is boosted with either ritonavir or cobicistat have not been established in pediatric patients weighing <35 kg
- 25 to <35 kg: 200 mg/25 mg PO qDay
- 14 to <25 kg: 120 mg/15 mg PO qDay
HIV-1 Pre-exposure Prophylaxis
Indicated for at-risk adolescents weighing ≥35 kg to reduce the risk of HIV-1 infection from sex, excluding those who at risk from receptive vaginal sex
<35 kg: Safety and efficacy not established
≥35 kg: 200 mg/25 mg PO qDay
Dosage Modifications
Renal impairment (weight ≥35 kg)
- Mild-to-moderate (CrCl ≥30 mL/min): No dosage adjustment required
- Severe (CrCl 15 to <30 mL/min): Not recommended
-
CrCl ≤15 mL/min
- Receiving chronic hemodialysis: On days of hemodialysis, administer daily dose after hemodialysis completion
- Not receiving chronic hemodialysis: Not recommended
- Coadministration of HIV-1 protease inhibitor (ie, ritonavir, cobicistat) with or without hemodialysis: Safety and efficacy not established
-
Hepatic impairment
- Mild-to-moderate (Child Pugh class A or B): No dosage adjustment required
- Severe (Child Pugh class C): Not studied
Dosing Considerations
For specific dosing recommendations for coadministered third agents for HIV treatment, refer to their respective prescribing information or AIDSinfo guidelines
HIV-1 screening for for HIV-1 PrEP
- Screen for HIV-1 infection immediately before initiating for HIV-1 PrEP and at least once q3Months during treatment, and upon diagnosis of any other sexually transmitted infections (STIs)
- If recent (<1 month) exposure to HIV-1 are suspected or clinical symptoms consistent with acute HIV-1 infection are present, use a test approved or cleared by the FDA to aid in the diagnosis of acute or primary HIV-1 infection
Laboratory testing
- Must have negative HIV-1 test immediately before initiating drug for HIV-1 PrEP
- Test for hepatitis B virus infection before initiating for HIV treatment or PrEP
- Assess estimated CrCl, urine glucose and urine protein before initiating therapy and monitor during therapy in all patients
Limitation of use
- Indication for PrEP does not include use in individuals at risk of HIV-1 from receptive vaginal sex
- Effectiveness in this population has not been evaluated
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Contraindicated (3)
- elvitegravir/cobicistat/emtricitabine/tenofovir DF
emtricitabine, elvitegravir/cobicistat/emtricitabine/tenofovir DF. Other (see comment). Contraindicated. Comment: Elvitegravir/cobicistat/emtricitabine/tenofovir is a complete regimen for HIV and should not be administered with other antiretrovirals.
- fezolinetant
tenofovir AF will increase the level or effect of fezolinetant by affecting hepatic enzyme CYP1A2 metabolism. Contraindicated. Fezolinetant AUC and peak plasma concentration are increased if coadministered with drugs that are weak, moderate, or strong CYP1A2 inhibitors
- lamivudine
emtricitabine and lamivudine both increase risk of immune reconstitution syndrome. Contraindicated. Coadministration of emtricitabine containing products and lamivudine containing products should be avoided. Combination will result in therapeutic duplication.
emtricitabine, lamivudine. Other (see comment). Contraindicated. Comment: Coadministration of emtricitabine containing products and lamivudine containing products should be avoided. Combination will result in therapeutic duplication.
Serious - Use Alternative (4)
- betibeglogene autotemcel
emtricitabine, betibeglogene autotemcel. Other (see comment). Avoid or Use Alternate Drug. Comment: Do not take antiretroviral medications for at least 1 month before mobilization or expected duration for elimination of the medications, and until all cycles of apheresis are completed. Antiretroviral medications may interfere with manufacturing of apheresed cells.
- cabotegravir
emtricitabine, cabotegravir. Other (see comment). Avoid or Use Alternate Drug. Comment: Cabotegravir plus rilpivirine is a complete regimen. Coadministration with other antiretroviral medications for treating HIV-1 infection is not recommended.
- elivaldogene autotemcel
elivaldogene autotemcel, emtricitabine. Either decreases effects of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Patients should not take antiretroviral medications for at least 1 month before initiating medications for stem cell mobilization, for the duration of the medications? elimination, and until all cycles of apheresis are completed.
- leniolisib
leniolisib will increase the level or effect of tenofovir AF by Other (see comment). Avoid or Use Alternate Drug. Leniolisib, a BCRP inhibitor, may increase systemic exposure of BCRP substrates
Monitor Closely (67)
- abacavir
abacavir and emtricitabine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.
- acalabrutinib
acalabrutinib increases levels of tenofovir AF by Other (see comment). Use Caution/Monitor. Comment: Acalabrutinib may increase exposure to coadministered BCRP substrates by inhibition of intestinal BCRP.
- acyclovir
acyclovir increases levels of emtricitabine by Other (see comment). Use Caution/Monitor. Comment: Coadministration of emtricitabine with drugs that reduce renal function or compete for active tubular secretion may increase serum concentrations of emtricitabine.
- adefovir
adefovir increases levels of emtricitabine by Other (see comment). Use Caution/Monitor. Comment: Coadministration of emtricitabine with drugs that reduce renal function or compete for active tubular secretion may increase serum concentrations of emtricitabine.
- apalutamide
apalutamide will decrease the level or effect of tenofovir AF by increasing elimination. Use Caution/Monitor. Apalutamide weakly induces BCRP and may decrease systemic exposure of drugs that are BCRP substrates.
- atazanavir
atazanavir and emtricitabine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.
- berotralstat
berotralstat will increase the level or effect of tenofovir AF by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Monitor or titrate P-gp substrate dose if coadministered.
- cabozantinib
tenofovir AF will increase the level or effect of cabozantinib by Other (see comment). Use Caution/Monitor. MRP2 inhibitors increase cabozantinib toxicity
- celecoxib
emtricitabine, celecoxib. Either increases levels of the other by decreasing renal clearance. Modify Therapy/Monitor Closely. Toxicity may result from coadministration of emtricitabine with other drugs that are also primarily excreted by glomerular filtration and/or active tubular secretion including high-dose or multiple-dose NSAIDs; alternatives to NSAIDs should be considered.
- cidofovir
cidofovir increases levels of emtricitabine by Other (see comment). Use Caution/Monitor. Comment: Coadministration of emtricitabine with drugs that reduce renal function or compete for active tubular secretion may increase serum concentrations of emtricitabine.
- darolutamide
darolutamide will increase the level or effect of tenofovir AF by Other (see comment). Modify Therapy/Monitor Closely. Darolutamide is a BCRP inhibitor. Avoid coadministration with BCRP inhibitors. If use is unavoidable, closely monitor for adverse reactions and consider dose reduction of BCRP substrate drug (refer BCRP substrate prescribing information).
- diclofenac
emtricitabine, diclofenac. Either increases levels of the other by decreasing renal clearance. Modify Therapy/Monitor Closely. Toxicity may result from coadministration of emtricitabine with other drugs that are also primarily excreted by glomerular filtration and/or active tubular secretion including high-dose or multiple-dose NSAIDs; alternatives to NSAIDs should be considered.
- diflunisal
emtricitabine, diflunisal. Either increases levels of the other by decreasing renal clearance. Modify Therapy/Monitor Closely. Toxicity may result from coadministration of emtricitabine with other drugs that are also primarily excreted by glomerular filtration and/or active tubular secretion including high-dose or multiple-dose NSAIDs; alternatives to NSAIDs should be considered.
- duvelisib
tenofovir AF will decrease the level or effect of duvelisib by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- efavirenz
efavirenz and emtricitabine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.
- elagolix
elagolix will increase the level or effect of tenofovir AF by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor.
- encorafenib
encorafenib will increase the level or effect of tenofovir AF by Other (see comment). Modify Therapy/Monitor Closely. Encorafenib (a BCRP inhibitor) may increase the concentration and toxicities of BCRP substrates. Closely monitor for signs and symptoms of increased exposure and consider adjusting the dose of these substrates.
- enfuvirtide
emtricitabine and enfuvirtide both increase risk of immune reconstitution syndrome. Use Caution/Monitor.
- etodolac
emtricitabine, etodolac. Either increases levels of the other by decreasing renal clearance. Modify Therapy/Monitor Closely. Toxicity may result from coadministration of emtricitabine with other drugs that are also primarily excreted by glomerular filtration and/or active tubular secretion including high-dose or multiple-dose NSAIDs; alternatives to NSAIDs should be considered.
- fenoprofen
emtricitabine, fenoprofen. Either increases levels of the other by decreasing renal clearance. Modify Therapy/Monitor Closely. Toxicity may result from coadministration of emtricitabine with other drugs that are also primarily excreted by glomerular filtration and/or active tubular secretion including high-dose or multiple-dose NSAIDs; alternatives to NSAIDs should be considered.
- flurbiprofen
emtricitabine, flurbiprofen. Either increases levels of the other by decreasing renal clearance. Modify Therapy/Monitor Closely. Toxicity may result from coadministration of emtricitabine with other drugs that are also primarily excreted by glomerular filtration and/or active tubular secretion including high-dose or multiple-dose NSAIDs; alternatives to NSAIDs should be considered.
- fosamprenavir
fosamprenavir and emtricitabine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.
- fostamatinib
fostamatinib will increase the level or effect of tenofovir AF by decreasing metabolism. Use Caution/Monitor. Concomitant use of fostamatinib may increase concentrations of BCRP substrate drugs. Monitor for toxicities of BCRP substrate drug that may require dosage reduction when given concurrently with fostamatinib.
- ganciclovir
ganciclovir, emtricitabine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of hematologic toxicity.
ganciclovir increases levels of emtricitabine by Other (see comment). Use Caution/Monitor. Comment: Coadministration of emtricitabine with drugs that reduce renal function or compete for active tubular secretion may increase serum concentrations of emtricitabine. - glecaprevir/pibrentasvir
glecaprevir/pibrentasvir will increase the level or effect of tenofovir AF by decreasing metabolism. Use Caution/Monitor. Glecaprevir/pibrentasvir may increase plasma concentration of BCRP substrates.
- ibuprofen
emtricitabine, ibuprofen. Either increases levels of the other by decreasing renal clearance. Modify Therapy/Monitor Closely. Toxicity may result from coadministration of emtricitabine with other drugs that are also primarily excreted by glomerular filtration and/or active tubular secretion including high-dose or multiple-dose NSAIDs; alternatives to NSAIDs should be considered.
- ibuprofen IV
emtricitabine, ibuprofen IV. Either increases levels of the other by decreasing renal clearance. Modify Therapy/Monitor Closely. Toxicity may result from coadministration of emtricitabine with other drugs that are also primarily excreted by glomerular filtration and/or active tubular secretion including high-dose or multiple-dose NSAIDs; alternatives to NSAIDs should be considered.
- ifosfamide
ifosfamide, tenofovir AF. Either increases toxicity of the other by nephrotoxicity and/or ototoxicity. Modify Therapy/Monitor Closely. Monitor electrolytes and renal function.
- indinavir
indinavir and emtricitabine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.
- indomethacin
emtricitabine, indomethacin. Either increases levels of the other by decreasing renal clearance. Modify Therapy/Monitor Closely. Toxicity may result from coadministration of emtricitabine with other drugs that are also primarily excreted by glomerular filtration and/or active tubular secretion including high-dose or multiple-dose NSAIDs; alternatives to NSAIDs should be considered.
- istradefylline
istradefylline will increase the level or effect of tenofovir AF by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of P-gp substrates in clinical trials. Consider dose reduction of sensitive P-gp substrates.
- ketoprofen
emtricitabine, ketoprofen. Either increases levels of the other by decreasing renal clearance. Modify Therapy/Monitor Closely. Toxicity may result from coadministration of emtricitabine with other drugs that are also primarily excreted by glomerular filtration and/or active tubular secretion including high-dose or multiple-dose NSAIDs; alternatives to NSAIDs should be considered.
- ketorolac
emtricitabine, ketorolac. Either increases levels of the other by decreasing renal clearance. Modify Therapy/Monitor Closely. Toxicity may result from coadministration of emtricitabine with other drugs that are also primarily excreted by glomerular filtration and/or active tubular secretion including high-dose or multiple-dose NSAIDs; alternatives to NSAIDs should be considered.
- lonafarnib
lonafarnib will increase the level or effect of tenofovir AF by P-glycoprotein (MDR1) efflux transporter. Modify Therapy/Monitor Closely. Lonafarnib is a weak P-gp inhibitor. Monitor for adverse reactions if coadministered with P-gp substrates where minimal concentration changes may lead to serious or life-threatening toxicities. Reduce P-gp substrate dose if needed.
- meclofenamate
emtricitabine, meclofenamate. Either increases levels of the other by decreasing renal clearance. Modify Therapy/Monitor Closely. Toxicity may result from coadministration of emtricitabine with other drugs that are also primarily excreted by glomerular filtration and/or active tubular secretion including high-dose or multiple-dose NSAIDs; alternatives to NSAIDs should be considered.
- mefenamic acid
emtricitabine, mefenamic acid. Either increases levels of the other by decreasing renal clearance. Modify Therapy/Monitor Closely. Toxicity may result from coadministration of emtricitabine with other drugs that are also primarily excreted by glomerular filtration and/or active tubular secretion including high-dose or multiple-dose NSAIDs; alternatives to NSAIDs should be considered.
- meloxicam
emtricitabine, meloxicam. Either increases levels of the other by decreasing renal clearance. Modify Therapy/Monitor Closely. Toxicity may result from coadministration of emtricitabine with other drugs that are also primarily excreted by glomerular filtration and/or active tubular secretion including high-dose or multiple-dose NSAIDs; alternatives to NSAIDs should be considered.
- nabumetone
emtricitabine, nabumetone. Either increases levels of the other by decreasing renal clearance. Modify Therapy/Monitor Closely. Toxicity may result from coadministration of emtricitabine with other drugs that are also primarily excreted by glomerular filtration and/or active tubular secretion including high-dose or multiple-dose NSAIDs; alternatives to NSAIDs should be considered.
- naproxen
emtricitabine, naproxen. Either increases levels of the other by decreasing renal clearance. Modify Therapy/Monitor Closely. Toxicity may result from coadministration of emtricitabine with other drugs that are also primarily excreted by glomerular filtration and/or active tubular secretion including high-dose or multiple-dose NSAIDs; alternatives to NSAIDs should be considered.
- nelfinavir
nelfinavir and emtricitabine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.
- nevirapine
emtricitabine and nevirapine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.
- nirmatrelvir
nirmatrelvir will increase the level or effect of tenofovir AF by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration may increase tenofovir systemic exposures.
- nirmatrelvir/ritonavir
nirmatrelvir/ritonavir will increase the level or effect of tenofovir AF by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Coadministration may increase tenofovir systemic exposures.
- orlistat
orlistat will decrease the level or effect of tenofovir AF by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Loss of virological control reported in HIV-infected patients taking orlistat concomitantly. Exact mechanism is unclear, but may include a drug-drug interaction that inhibits systemic absorption of the antiretroviral drug. Monitor HIV RNA levels frequently and if increased HIV viral load confirmed, discontinue orlistat.
orlistat will decrease the level or effect of emtricitabine by inhibition of GI absorption. Applies only to oral form of both agents. Use Caution/Monitor. Loss of virological control reported in HIV-infected patients taking orlistat concomitantly. Exact mechanism is unclear, but may include a drug-drug interaction that inhibits systemic absorption of the antiretroviral drug. Monitor HIV RNA levels frequently and if increased HIV viral load confirmed, discontinue orlistat. - oteseconazole
oteseconazole will increase the level or effect of tenofovir AF by Other (see comment). Modify Therapy/Monitor Closely. Otesezonale, a BCRP inhibitor, may increase the effects and risk of toxicities of BCRP substrates. Use lowest starting dose of BCRP substrate, or consider reducing BCRP substrate dose.
- oxaprozin
emtricitabine, oxaprozin. Either increases levels of the other by decreasing renal clearance. Modify Therapy/Monitor Closely. Toxicity may result from coadministration of emtricitabine with other drugs that are also primarily excreted by glomerular filtration and/or active tubular secretion including high-dose or multiple-dose NSAIDs; alternatives to NSAIDs should be considered.
- piroxicam
emtricitabine, piroxicam. Either increases levels of the other by decreasing renal clearance. Modify Therapy/Monitor Closely. Toxicity may result from coadministration of emtricitabine with other drugs that are also primarily excreted by glomerular filtration and/or active tubular secretion including high-dose or multiple-dose NSAIDs; alternatives to NSAIDs should be considered.
- regorafenib
regorafenib will increase the level or effect of tenofovir AF by Other (see comment). Modify Therapy/Monitor Closely. Regorafenib likely inhibits BCRP (ABCG2) transport. Coadministration with a BCRP substrate may increase systemic exposure to the substrate and related toxicity.
- ribavirin
ribavirin increases toxicity of emtricitabine by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of lactic acidosis.
- ritonavir
ritonavir and emtricitabine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.
- safinamide
safinamide will increase the level or effect of tenofovir AF by Other (see comment). Use Caution/Monitor. Safinamide and its major metabolite may inhibit intestinal BCRP. Monitor BCRP substrates for increased pharmacologic or adverse effects.
- saquinavir
saquinavir and emtricitabine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.
- sarecycline
sarecycline will increase the level or effect of tenofovir AF by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Monitor for toxicities of P-gp substrates that may require dosage reduction when coadministered with P-gp inhibitors.
- stavudine
emtricitabine and stavudine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.
- stiripentol
stiripentol will increase the level or effect of tenofovir AF by Other (see comment). Use Caution/Monitor. Stiripentol is a BCRP transport inhibitor. Consider dosage reduction for BCRP substrates if adverse effects are experienced when coadministered.
- sulindac
emtricitabine, sulindac. Either increases levels of the other by decreasing renal clearance. Modify Therapy/Monitor Closely. Toxicity may result from coadministration of emtricitabine with other drugs that are also primarily excreted by glomerular filtration and/or active tubular secretion including high-dose or multiple-dose NSAIDs; alternatives to NSAIDs should be considered.
- tafamidis
tafamidis will increase the level or effect of tenofovir AF by Other (see comment). Use Caution/Monitor. Tafamidis inhibits breast cancer resistant protein (BCRP) in vitro and may increase exposure of BCRP substrates following tafamidis or tafamidis meglumine administration. Dosage adjustment of these BCRP substrates may be necessary.
- tafamidis meglumine
tafamidis meglumine will increase the level or effect of tenofovir AF by Other (see comment). Use Caution/Monitor. Tafamidis inhibits breast cancer resistant protein (BCRP) in vitro and may increase exposure of BCRP substrates following tafamidis or tafamidis meglumine administration. Dosage adjustment of these BCRP substrates may be necessary.
- tenofovir DF
emtricitabine and tenofovir DF both increase risk of immune reconstitution syndrome. Use Caution/Monitor.
- tipranavir
tipranavir and emtricitabine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.
- tolmetin
emtricitabine, tolmetin. Either increases levels of the other by decreasing renal clearance. Modify Therapy/Monitor Closely. Toxicity may result from coadministration of emtricitabine with other drugs that are also primarily excreted by glomerular filtration and/or active tubular secretion including high-dose or multiple-dose NSAIDs; alternatives to NSAIDs should be considered.
- tucatinib
tucatinib will increase the level or effect of tenofovir AF by P-glycoprotein (MDR1) efflux transporter. Use Caution/Monitor. Consider reducing the dosage of P-gp substrates, where minimal concentration changes may lead to serious or life-threatening toxicities.
- ublituximab
ublituximab decreases effects of emtricitabine by immunosuppressive effects; risk of infection. Modify Therapy/Monitor Closely.
- valacyclovir
valacyclovir increases levels of emtricitabine by Other (see comment). Use Caution/Monitor. Comment: Coadministration of emtricitabine with drugs that reduce renal function or compete for active tubular secretion may increase serum concentrations of emtricitabine.
- valganciclovir
valganciclovir, emtricitabine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Use alternatives if available. Increased risk of hematologic toxicity.
valganciclovir increases levels of emtricitabine by Other (see comment). Use Caution/Monitor. Comment: Coadministration of emtricitabine with drugs that reduce renal function or compete for active tubular secretion may increase serum concentrations of emtricitabine. - voclosporin
voclosporin, tenofovir AF. Either increases toxicity of the other by nephrotoxicity and/or ototoxicity. Modify Therapy/Monitor Closely. Coadministration with drugs associated with nephrotoxicity may increase the risk for acute and/or chronic nephrotoxicity.
- zidovudine
emtricitabine and zidovudine both increase risk of immune reconstitution syndrome. Use Caution/Monitor.
Minor (1)
- nirmatrelvir/ritonavir
nirmatrelvir/ritonavir will increase the level or effect of emtricitabine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
Adverse Effects
1-10%
Adults
Nausea (10%)
Bone mineral density (BMD) decline spine ≥5% (10%)
BMD decline femoral neck ≥7% (7%)
Diarrhea (5%)
Headache (2%)
Fatigue (2%)
Abdominal pain (2%)
Postmarketing Reports
Skin and subcutaneous tissue disorders: Angioedema, urticaria, rash
Renal and urinary disorders: Acute renal failure, acute tubular necrosis, proximal renal tubulopathy, Fanconi syndrome
Warnings
Black Box Warnings
Post-treatment acute exacerbation of hepatitis B
- Severe acute exacerbations of hepatitis B (HBV) reported in HBV-infected individuals who discontinued products containing emtricitabine (FTC) and/or tenofovir disoproxil fumarate (TDF) and may occur with discontinuation of drug
Monitor hepatic function closely with both clinical and laboratory follow-up for at least several months in individuals infected with HBV who discontinue therapy
- If appropriate, initiation of antihepatitis B therapy may be warranted
Risk of drug resistance if prescribed for PrEP in undiagnosed early HIV-1 infection
- Use for HIV-1 PrEP must only be prescribed to individuals confirmed to be HIV-negative immediately before initiating and reconfirmed at least every 3 months during use
- Drug-resistant HIV-1 variants have been identified with use for HIV-1 PrEP following undetected acute HIV-1 infection
- Do not initiate for HIV-1 PrEP if signs or symptoms of acute HIV-1 infection are present unless negative infection status is confirmed
Contraindications
Use for HIV-1 PrEP is contraindicated in individuals with unknown or positive HIV-1 status
Cautions
All individuals should be tested for the presence of chronic HBV infection before initiating ART therapy or PrEP; emtricitabine/tenofovir AF is not approved for treatment of chronic HBV infection, and safety and efficacy are not established in patients coinfected with HIV-1 and HBV (see Black Box Warnings)
Use for HIV-1 PrEP to reduce the risk of HIV-1 infection is part of a comprehensive prevention strategy, including adherence to daily administration and safer sex practices, including condoms, to reduce the risk of sexually transmitted infections (STIs); the time from initiation of emtricitabine/tenofovir AF for HIV-1 PrEP to maximal protection against HIV-1 infection is unknown
Before initiating for PrEP, individuals must be confirmed to be HIV-1 negative; HIV-1 resistance substitutions may emerge in individuals with undetected HIV-1 infection who are taking only emtricitabine/tenofovir AF, which alone does not constitute a complete HIV-1 treatment regimen; while using for PrEP, testing should be repeated at least every 3 months, and upon diagnosis or any other STD
Immune reconstitution syndrome reported with combination ART therapy, including emtricitabine; during initial phase of combination ART treatment, patients whose immune system responds may develop inflammatory response to indolent or residual opportunistic infections (eg, Mycobacterium avium infection, cytomegalovirus, Pneumocystis jirovecii pneumonia [PCP], or tuberculosis), which may necessitate further evaluation and treatment; autoimmune disorders (eg, Grave disease, polymyositis, Guillain-Barré syndrome) may also emerge
New-onset or worsening renal impairment reported with tenofovir, including cases of acute renal failure and Fanconi syndrome
Lactic acidosis and severe hepatomegaly with steatosis, including fatal cases, reported with the use of nucleoside analogs, alone or in combination with other ARTs; suspend treatment with clinical or laboratory findings suggestive of lactic acidosis or pronounced hepatotoxicity
Worsening renal impairment
- Postmarketing cases of renal impairment, including acute renal failure, proximal renal tubulopathy (PRT), and Fanconi syndrome reported; while most of these cases were characterized by potential confounders that may have contributed to reported renal events, it is also possible these factors may have predisposed patients to tenofovir-related adverse reactions
- Not recommended in individuals with estimated creatinine clearance of 15 to below 30 mL/min, or individuals with estimated creatinine clearance below 15 mL/min who are not receiving chronic hemodialysis
- Individuals taking tenofovir prodrugs who have impaired renal function and those taking nephrotoxic agents including non-steroidal anti-inflammatory drugs are at increased risk of developing renal-related adverse reactions
- Prior to or when initiating therapy and during treatment on a clinically appropriate schedule, assess serum creatinine, estimated creatinine clearance, urine glucose, and urine protein in all individuals
- In individuals with chronic kidney disease, also assess serum phosphorus; discontinue drug in individuals who develop clinically significant decreases in renal function or evidence of Fanconi syndrome.
Drug interaction overview
- Not for administration with other drugs containing emtricitabine or tenofovir DF, or containing tenofovir AF
-
Tenofovir AF
- Tenofovir AF is a substrate of P-gp, BCRP, OATP1B1, and OATP1B3
- Drugs that strongly affect P-gp and BCRP activity may lead to changes in tenofovir AF absorption
- Drugs that induce P-gp activity are expected to decrease tenofovir AF absorption, resulting in decreased plasma concentration, which may lead to loss of therapeutic effect and development of resistance
- Coadministration with drugs that inhibit P-gp and BCRP may increase tenofovir AF absorption and plasma concentration
-
Effects in renal function
- Emtricitabine and tenofovir are primarily excreted by the kidneys by glomerular filtration and active tubular secretion
- Postmarketing cases of renal impairment, including acute renal failure, proximal renal tubulopathy (PRT), and Fanconi syndrome reported with tenofovir AF-containing products reported
- Coadministration of emtricitabine/tenofovir AF with drugs that reduce renal function or compete for active tubular secretion may increase emtricitabine/tenofovir AF; thereby, increasing risk for adverse effects
Pregnancy
Pregnancy
Pregnancy exposure registry monitors pregnancy outcomes in women exposed to drug during pregnancy; healthcare providers are encouraged to register patients by calling the Antiretroviral Pregnancy Registry (APR) at 1-800-258-4263
There are insufficient human data on use during pregnancy to inform a drug-associated risk of birth defects and miscarriage; tenofovir alafenamide (TAF) use in women during pregnancy has not been evaluated; however, emtricitabine (FTC) use during pregnancy has been evaluated in a limited number of women reported to the APR
Available data from APR show no difference in risk of overall major birth defects for FTC (2.4%) compared with background rate for major birth defects of 2.7% in a U.S. reference population of Metropolitan Atlanta Congenital Defects Program (MACDP); the rate of miscarriage is not reported in the APR
Lactation
The Centers for Disease Control and Prevention recommend that HIV-infected mothers not breastfeed infants, to avoid risking postnatal transmission of HIV
FTC has been shown to be present in human breast milk; not known if TAF is present in human breast milk; tenofovir has been shown to be present in milk of lactating rats and rhesus monkeys after administration of TDF; not known if TAF is present in animal milk
Not known if drug combination affects milk production or has effects on breastfed child; because of potential for HIV transmission (in HIV-negative infants), developing viral resistance (in HIV-positive infants), and adverse reactions in a breastfed infant similar to those seen in adults, instruct mothers not to breastfeed if they are receiving therapy
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Emtricitabine: Nucleoside reverse transcriptase inhibitor (NRTI); following phosphorylation, interferes with HIV viral DNA polymerase and inhibits viral replication; cytosine analogue
Tenofovir AF: NRTI prodrug of tenofovir; compared with tenofovir disoproxil fumarate (tenofovir DF, Viread), tenofovir alafenamide (AF) is a more targeted form of tenofovir that has demonstrated high antiviral efficacy at a dose that is 10 times lower than tenofovir DF, as well as an improved renal and bone safety profile; inhibits HIV-1 RT by competing with the natural substrate deoxyadenosine 5′-triphosphate and, after incorporation into DNA, by DNA chain termination
Absorption
Adults
-
Emtricitabine
- Peak plasma time: 3 hr
- Peak plasma concentration: 2.1 mcg/mL
- Trough plasma concentration: 0.1 mcg/mL
- AUC: 11.7 mcg⋅hr/mL
-
Tenofovir
- Peak plasma time: 1 hr
- Peak plasma concentration: 0.16 mcg/mL
- AUC: 0.21 mcg⋅hr/mL
Adolescents aged 12 to <18 years
-
Emtricitabine
- Peak plasma concentration: 2.3 mcg/mL
- Trough plasma concentration: 0.1 mcg/mL
- AUC: 14.4 mcg⋅hr/mL
-
Tenofovir
- Peak plasma concentration: 0.17 mcg/mL
- AUC: 0.2 mcg⋅hr/mL
Children aged 6 to <12 years
-
Emtricitabine
- Peak plasma concentration: 3.4 mcg/mL
- Trough plasma concentration: 0.11 mcg/mL
- AUC: 20.6 mcg⋅hr/mL
-
Tenofovir
- Peak plasma concentration: 0.31 mcg/mL
- AUC: 0.33 mcg⋅hr/mL
Children aged ≥2 years (weight 14 to <25 kg)
-
Emtricitabine
- Peak plasma concentration: 3.85 mcg/mL
- Trough plasma concentration: 0.21 mcg/mL
- AUC: 15 mcg⋅hr/mL
-
Tenofovir
- Peak plasma concentration: 0.414 mcg/mL
- AUC: 0.305 mcg⋅hr/mL
Distribution
Emtricitabine
- Protein bound: <4%
Tenofovir
- Protein bound: 80%
- Vd: 1.2-1.3 L/kg
Metabolism
Emtricitabine
- Not significantly metabolized
- Metabolized by oxidation
Tenofovir
- Tenofovir AF (TAF) is hydrolyzed within cells to form tenofovir (major metabolite), which is phosphorylated to the active metabolite, tenofovir diphosphate
- In vitro studies have shown that TAF is metabolized to tenofovir by cathepsin A in PBMCs and macrophages and by CES1 in hepatocytes
- Upon coadministration with the moderate CYP3A inducer probe efavirenz, TAF exposure was unaffected
Elimination
Emtricitabine
- Half-life: 10 hr
- Dialyzable: 30% removed by hemodialysis
- Excretion: 70% urine; 13.7% feces
Tenofovir
- Half-life: 0.51 hr
- Excretion: 31.7% feces; <1% urine
Administration
Oral Administration
May take with or without food
Storage
Store at 25°C (77°F); excursions permitted to 15-30ºC (59-86ºF)
Keep container tightly closed
Dispense only in original container
Images
Formulary
Adding plans allows you to compare formulary status to other drugs in the same class.
To view formulary information first create a list of plans. Your list will be saved and can be edited at any time.
Adding plans allows you to:
- View the formulary and any restrictions for each plan.
- Manage and view all your plans together – even plans in different states.
- Compare formulary status to other drugs in the same class.
- Access your plan list on any device – mobile or desktop.
