Tuesday, October 18, 2016

Emtriva


Generic Name: Emtricitabine
Class: Nucleoside and Nucleotide Reverse Transcriptase Inhibitors
VA Class: AM800
Chemical Name: 5-Fluoro-1-(2R, 5S)-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl] cytosine
Molecular Formula: C8H10FN3O3S
CAS Number: 143491-57-0



  • Lactic acidosis and severe hepatomegaly with steatosis (including some fatalities) reported rarely in patients receiving nucleoside reverse transcriptase inhibitors (NRTIs) alone or in conjunction with other antiretrovirals.1 (See Hepatic Effects and Lactic Acidosis under Cautions.)




  • Single entity or fixed-combination preparations containing emtricitabine not indicated for treatment of chronic hepatitis B virus (HBV) infection; safety and efficacy not established for treatment of HIV infection in patients coinfected with HBV.1




  • Severe, acute exacerbations of HBV reported following discontinuance of emtricitabine.1 Monitor hepatic function closely with both clinical and laboratory follow-up for at least several months after emtricitabine is discontinued in patients coinfected with HBV and HIV.1 If appropriate, initiation of treatment for HBV infection may be warranted.1




Introduction

Antiretroviral; nucleoside reverse transcriptase inhibitor (NRTI).1


Uses for Emtriva


Treatment of HIV Infection


Treatment of HIV-1 infection in conjunction with other antiretrovirals.1 2 3


A preferred or alternative NRTI for use in multiple-drug antiretroviral regimens for initial therapy in adults.4


Fixed-combination preparation containing emtricitabine and tenofovir (Truvada) used in conjunction with other antiretrovirals.10 Can be used to decrease pill burden,4 but should not be used as a component of a triple NRTI regimen.10


Fixed-combination preparation containing efavirenz, emtricitabine, and tenofovir (Atripla) used alone or in conjunction with other antiretrovirals.14 Used to decrease pill burden and improve compliance.14


Base decision to use emtricitabine in previously treated adults on laboratory testing (e.g., genotype testing, phenotype testing) and treatment history.1


For treatment of HIV in patients coinfected with hepatitis B virus (HBV), some experts recommend an NRTI combination of tenofovir and (emtricitabine or lamivudine); avoid use of only 1 of these antiretrovirals (may increase risk of HBV resistance).4 17


Postexposure Prophylaxis following Occupational Exposure to HIV


Postexposure prophylaxis of HIV infection in health-care workers and others exposed occupationally via percutaneous injury or mucous membrane or nonintact skin contact with blood, tissues, or other body fluids associated with risk for transmission of the virus.13 Used in conjunction with other antiretrovirals.13


Postexposure Prophylaxis following Nonoccupational Exposure to HIV


Postexposure prophylaxis of HIV infection in individuals who have had nonoccupational exposure to blood, genital secretions, or other potentially infectious body fluids of a person known to be infected with HIV when that exposure represents a substantial risk for HIV transmission.12 Used in conjunction with other antiretrovirals.12


Emtriva Dosage and Administration


Administration


Oral Administration


Administer single-entity preparation (Emtriva) or fixed-combination preparation (Truvada) orally without regard to meals.1 10 Administer fixed-combination preparation (Atripla) orally once daily on an empty stomach, preferably at bedtime.14


Because the dosage of emtricitabine and tenofovir cannot be adjusted individually, the fixed combination containing emtricitabine and tenofovir (Truvada) should not be used in pediatric patients; patients with severe renal impairment (Clcr <30 mL/minute); or patients who experience dose-limiting adverse effects.10


Because the dosage of efavirenz, emtricitabine, and tenofovir cannot be adjusted individually, the fixed combination containing efavirenz, emtricitabine, and tenofovir (Atripla) should not be used in patients with moderate to severe renal impairment (Clcr <50 mL/minute).14


Dosage


Emtricitabine capsules and oral solution are not bioequivalent.1 (See Bioavailability under Pharmacokinetics.)


Emtriva and Truvada must be given in conjunction with other antiretrovirals.1 10 Atripla may be used alone or in conjunction with other antiretrovirals.14


Dosage of Truvada and Atripla expressed as number of tablets.10 14


Pediatric Patients


Treatment of HIV Infection

Oral

Infants 0–3 months of age: 3 mg/kg (as the oral solution) once daily.1


Children 3 months to 17 years of age: 6 mg/kg (up to a maximum of 240 mg as the oral solution) once daily.1 11


Children weighing >33 kg who can swallow an intact capsule: 200 mg (as the capsule) once daily.1 11


Adults


Treatment of HIV Infection

Oral

200 mg (as the capsule) once daily.1 Alternatively, 240 mg (as the oral solution) once daily.1 4


Truvada: 1 tablet once daily.4 10


Atripla: 1 tablet once daily.4 14


Postexposure Prophylaxis following Occupational Exposure to HIV

Oral

200 mg (as the capsule) once daily.13


Initiate postexposure prophylaxis as soon as possible following exposure (within hours rather than days) and continue for 4 weeks, if tolerated.13


Postexposure Prophylaxis following Nonoccupational Exposure to HIV

Oral

200 mg (as the capsule) once daily.12


Initiate postexposure prophylaxis as soon as possible following exposure (preferably ≤72 hours after exposure) and continue for 28 days.12


Prescribing Limits


Pediatric Patients


Treatment of HIV Infection

Oral

Children 3 months to 17 years of age: Maximum 240 mg (as the oral solution) once daily.1


Special Populations


Renal Impairment


Treatment of HIV Infection

Oral

Reduce dosage in adults with Clcr <50 mL/minute (see tables).1


Data insufficient to make specific dosage recommendations for pediatric patients with renal impairment; consider reducing dose and/or increasing dosing interval.1





















Table 1. Emtriva Dosage in Adults with Renal Impairment14

Clcr (mL/minute)



Dosage of Capsules



Dosage of Oral Solution



≥50



200 mg every 24 hours



240 mg every 24 hours



30–49



200 mg every 48 hours



120 mg every 24 hours



15–29



200 mg every 72 hours



80 mg every 24 hours



<15



200 mg every 96 hours



60 mg every 24 hours



Hemodialysis patients



200 mg every 96 hours; on day of dialysis, give dose after the procedure



60 mg every 24 hours; give dose after hemodialysis











Table 2. Truvada Dosage in Adults with Renal Impairment10

Clcr (mL/minute)



Dose and Dosing Interval



≥50



One tablet every 24 hours



30–49



One tablet every 48 hours (monitor clinical response and renal function since dosage has not been evaluated clinically)



<30 (including hemodialysis patients)



Not recommended


Atripla: Dosage adjustment not necessary in patients with Clcr ≥50 mL/minute.14 Not recommended in patients with Clcr < 50 mL/minute.14


Geriatric Patients


Select dosage with caution because of age-related decreases in hepatic, renal, and/or cardiac function and concomitant disease and drug therapy.1


Cautions for Emtriva


Contraindications



  • Known hypersensitivity to emtricitabine or any ingredient in the formulation.1



Warnings/Precautions


Warnings


Hepatic Effects and Lactic Acidosis

Lactic acidosis and severe hepatomegaly with steatosis (sometimes fatal) reported in patients receiving emtricitabine.1 Reported most frequently in women; obesity and long-term NRTI therapy also may be risk factors.1 Has been reported in patients with no known risk factors.1


Use with caution in patients with known risk factors for liver disease.1


Interrupt therapy if there are clinical or laboratory findings suggestive of lactic acidosis or pronounced hepatotoxicity (e.g., hepatomegaly and steatosis even in the absence of marked increases in serum aminotransferase concentrations).1


HIV-infected Individuals Coinfected with Hepatitis B Virus (HBV)

Test all HIV patients for presence of HBV before initiating antiretroviral therapy.1


Not indicated for treatment of chronic HBV infection.1


Safety and efficacy not established for treatment of HIV infection in patients coinfected with HBV.1 (See Treatment of HIV Infection under Uses.)


Severe acute exacerbations of HBV reported following discontinuance of emtricitabine.1 Exacerbations of HBV have been associated with hepatic decompensation and hepatic failure.1 If used in those coinfected with HIV and HBV, closely monitor hepatic function (using both clinical and laboratory follow-up) for at least several months after emtricitabine is discontinued.1 If appropriate, initiation of treatment for HBV infection may be warranted.1


General Precautions


Do not use multiple emtricitabine-containing preparations concomitantly.1


Emtricitabine should not be administered with lamivudine or fixed-combination preparations containing lamivudine (Combivir, Epivir, Epivir-HBV, Epzicom, Trizivir).1


Use of Fixed Combinations

When used in fixed combination with tenofovir (Truvada), consider the cautions, precautions, and contraindications associated with tenofovir.10


When used in fixed combination with tenofovir and efavirenz (Atripla), consider the cautions, precautions, and contraindications associated with the concomitant agents.14


Adipogenic Effects

Possible redistribution or accumulation of body fat, including central obesity, dorsocervical fat enlargement (“buffalo hump”), peripheral wasting, breast enlargement, and general cushingoid appearance.1


Immune Reconstitution Syndrome

During initial treatment, patients who respond to antiretroviral therapy may develop an inflammatory response to indolent or residual opportunistic infections (e.g., Mycobacterium avium complex [MAC], M. tuberculosis, cytomegalovirus [CMV], Pneumocystis jiroveci [formerly P. carinii]);1 this may necessitate further evaluation and treatment.1


Specific Populations


Pregnancy

Category B.1


Antiretroviral Pregnancy Registry at 800-258-4263.1


Some experts state that emtricitabine is an alternative (not a preferred) NRTI for use in multiple-drug antiretroviral regimens in pregnant women.16


Lactation

Not known whether distributed into human milk.1


Instruct HIV-infected women not to breast-feed because of risk of HIV transmission and risk of adverse effects in the infant.1


Pediatric Use

Emtriva: Safety and efficacy in pediatric patients 3 months through 21 years of age supported by evidence from studies in pediatric patients.1


Pharmacokinetics evaluated in a limited number of neonates born to HIV-infected mothers; efficacy in preventing or treating HIV infection in these neonates not determined.1 20


Adverse effects reported in children similar to adults.1


Truvada: Safety and efficacy not established in children <18 years of age.8 10


Atripla: Safety and efficacy not established in children <18 years of age.14


Geriatric Use

Insufficient experience in those ≥65 years of age to determine whether they respond differently than younger adults.1


Select dosage with caution because of age-related decreases in hepatic, renal, and/or cardiac function and concomitant disease and drug therapy.1


Renal Impairment

Dosage adjustment necessary based on degree of renal impairment.1 Monitor clinical response and renal function in patients with renal impairment.1 (See Renal Impairment under Dosage and Administration.)


Hepatic Impairment

Emtricitabine not metabolized by liver enzymes; any impact of hepatic impairment expected to be limited.1


Use with caution in patients with known risk factors for liver disease.1


Common Adverse Effects


Mild to moderate headache; GI effects (diarrhea, nausea); rash.1


Interactions for Emtriva


Emtricitabine does not inhibit CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2C19, CYP2D6, or CYP3A4.1 Interactions with drugs metabolized by these CYP isoenzymes unlikely.1


Emtricitabine does not inhibit glucuronosyltransferase (uridine diphosphoglucuronosyltransferase, UDP-glucuronate β-d-glucuronosyltransferase [acceptor-unspecific]), an enzyme responsible for glucuronidation.1 Pharmacokinetic interactions unlikely.1


Specific Drugs



















































Drug



Interaction



Comments



Abacavir



In vitro evidence of additive or synergistic antiretroviral effects1



Darunavir



Pharmacokinetic interaction unlikely18



Delavirdine



In vitro evidence of additive or synergistic antiretroviral effects1



Efavirenz



In vitro evidence of additive or synergistic antiretroviral effects1



Famciclovir



Pharmacokinetic interaction unlikely1



Indinavir



Pharmacokinetic interaction unlikely1



Lamivudine



Do not use concomitantly;1 4 no potential benefit since emtricitabine is an analog of lamivudine and has the same resistance profile4



Nelfinavir



In vitro evidence of additive or synergistic antiretroviral effects1



Nevirapine



In vitro evidence of additive or synergistic antiretroviral effects1



Ritonavir



In vitro evidence of additive or synergistic antiretroviral effects1



Saquinavir



In vitro evidence of additive or synergistic antiretroviral effects1



Stavudine



Pharmacokinetic interaction unlikely1


In vitro evidence of additive or synergistic antiretroviral effects1



Tenofovir



Pharmacokinetic interaction unlikely1


In vitro evidence of additive or synergistic antiretroviral effects1



Tipranavir



In vitro evidence of additive antiretroviral effects19



Zidovudine



In vitro evidence of additive or synergistic antiretroviral effects1


Emtriva Pharmacokinetics


Absorption


Bioavailability


Rapidly and extensively absorbed; peak plasma concentrations attained within 1–2 hours.1


Capsules: Bioavailability is 93%.1


Oral solution: Bioavailability is 75%.1


Fixed-combination tablet containing emtricitabine 200 mg and tenofovir disoproxil fumarate 300 mg (Truvada) is bioequivalent to a 200-mg capsule of emtricitabine and a 300-mg tablet of tenofovir disoproxil fumarate given simultaneously.10


Fixed-combination tablet containing efavirenz 600 mg, tenofovir disoproxil fumarate 300 mg, and emtricitabine 200 mg (Atripla) is bioequivalent to a 600-mg tablet of efavirenz, a 300-mg tablet of tenofovir disoproxil fumarate, and a 200-mg capsule of emtricitabine given simultaneously.14


Food


Food does not appear to affect absorption.1


Special Populations


Peak plasma concentrations and AUC increased in patients with renal impairment due to a reduction in renal clearance of the drug.1 Dosage adjustment needed.1


AUC reported in pediatric patients 3 months to 17 years of age receiving the recommended dosage (6 mg/kg daily [up to 240 mg daily] as the oral solution or 200-mg capsule once daily) similar to that reported in adults receiving 200 mg daily.1 AUC reported in neonates receiving 3 mg/kg daily for 4 days similar to that reported in children 3 months to 17 years of age receiving the recommended dosage.1


Distribution


Extent


Not well characterized.1


Not known whether crosses the placenta or is distributed into milk.1


Plasma Protein Binding


<4 %.1


Elimination


Metabolism


Undergoes oxidation and conjugation with glucuronic acid.1


Intracellularly, emtricitabine is phosphorylated and converted by cellular enzymes to the active metabolite, emtricitabine 5′-triphosphate.1


Elimination Route


Excreted in urine (86%) and feces (14%).1 Eliminated by glomerular filtration and active tubular secretion.1


Removed by hemodialysis; not known whether removed by peritoneal dialysis.1


Half-life


10 hours.1


Special Populations


Renal impairment reduces renal clearance.1


Stability


Storage


Oral


Capsules

Emtriva: 25°C (may be exposed to 15–30°C).1


Solution

Emtriva: 2–8°C until dispensed.1 For patient use, store at 25°C (may be exposed to 15–30°C); use within 3 months.1


Tablets

Truvada: 25°C (may be exposed to 15–30°C).10


Atripla: 25°C (may be exposed to 15–30°C).14


Actions and SpectrumActions



  • Thio analog of cytidine.1




  • Pharmacologically related to other NRTIs (e.g., abacavir, didanosine, lamivudine, stavudine, zidovudine); differs structurally from these drugs; also differs pharmacologically and structurally from other currently available antiretroviral agents.1




  • Active in vitro against HIV-1 and HIV-2.1 Also has some activity against HBV.5 7




  • Inhibits replication of HIV by interfering with viral RNA-directed DNA polymerase (reverse transcriptase).1




  • Strains of HIV-1 with reduced susceptibility to emtricitabine have been produced in vitro and have emerged during therapy with the drug.1




  • Strains of HIV resistant to emtricitabine may be cross-resistant to some other NRTIs (e.g., lamivudine).1




  • Cross-resistance between emtricitabine and PIs is highly unlikely since the drugs have different target enzymes.4 Cross-resistance between emtricitabine and NNRTIs is considered to be low since the drugs bind at different sites on reverse transcriptase and have different mechanisms of action.4



Advice to Patients



  • Critical nature of compliance with HIV therapy.1 Importance of using emtricitabine in conjunction with other antiretrovirals—not for monotherapy.1




  • Antiretroviral therapy is not a cure for HIV infection, and opportunistic infections still may occur.1 HIV transmission via sexual contact or sharing needles is not prevented by antiretrovirals.1




  • Redistribution/accumulation of body fat may occur, with as yet unknown long-term health effects.1




  • Importance of informing clinician of existing or contemplated concomitant therapy, including prescription and OTC drugs and dietary or herbal products.1




  • Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed.1




  • Importance of advising patients of other important precautionary information.1 (See Cautions.)



Preparations


Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.


















Emtricitabine

Routes



Dosage Forms



Strengths



Brand Names



Manufacturer



Oral



Capsules



200 mg



Emtriva



Gilead



Solution



10 mg/mL



Emtriva



Gilead


















Emtricitabine Combinations

Routes



Dosage Forms



Strengths



Brand Names



Manufacturer



Oral



Tablets, film-coated



200 mg with Tenofovir Disoproxil Fumarate 300 mg



Truvada



Gilead



200 mg with Tenofovir Disoproxil Fumarate 300 mg and Efavirenz 600 mg



Atripla



Bristol-Myers Squibb and Gilead


Comparative Pricing


This pricing information is subject to change at the sole discretion of DS Pharmacy. This pricing information was updated 04/2011. Actual costs to patients will vary depending on the use of specific retail or mail-order locations and health insurance copays.


Atripla 600-200-300MG Tablets (BRISTOL-MYERS SQUIBB/GILEAD): 30/$1795.72 or 90/$5154.14


Emtriva 200MG Capsules (GILEAD SCIENCES): 30/$466 or 60/$883.01


Truvada 200-300MG Tablets (GILEAD SCIENCES): 30/$1071.69 or 90/$3180.65



Disclaimer

This report on medications is for your information only, and is not considered individual patient advice. Because of the changing nature of drug information, please consult your physician or pharmacist about specific clinical use.


The American Society of Health-System Pharmacists, Inc. and Drugs.com represent that the information provided hereunder was formulated with a reasonable standard of care, and in conformity with professional standards in the field. The American Society of Health-System Pharmacists, Inc. and Drugs.com make no representations or warranties, express or implied, including, but not limited to, any implied warranty of merchantability and/or fitness for a particular purpose, with respect to such information and specifically disclaims all such warranties. Users are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the information is provided for informational purposes only. The entire monograph for a drug should be reviewed for a thorough understanding of the drug's actions, uses and side effects. The American Society of Health-System Pharmacists, Inc. and Drugs.com do not endorse or recommend the use of any drug. The information is not a substitute for medical care.

AHFS Drug Information. © Copyright, 1959-2011, Selected Revisions November 01, 2009. American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland 20814.


† Use is not currently included in the labeling approved by the US Food and Drug Administration.




References



1. Gilead Sciences, Inc. Emtriva (emtricitabine) capsules prescribing information. Foster City, CA; 2008 May.



2. Saag M, Cahn P, Raffi F et al. A randomized, double-blind, multicenter comparison of emtricitabine QD to stavudine BID. Proceedings of ICAAC San Diego 2002. Abstract No. LB-1.



3. Sanne I, van der Horst C, Shaw A et al. Two randomized, controlled, equivalence trials of emtricitabine (FTC) to lamivudine (3TC). Poster presented at the XIV International AIDS Conference. Barcelona, Spain: 2002 Jul 7-12.



4. Panel on Antiretroviral Guidelines for Adults and Adolescents. Guidelines for the use of antiretroviral agents in HIV-1-infected adults and adolescents (November 3, 2008). From the US Department of Health and Human Services HIV/AIDS Information Services (AIDSinfo) website.



5. Seigneres B, Martin P, Werle B et al. Effects of pyrimidine and purine analog combinations in the duck hepatitis B virus infection model. Antimicrob Agents Chemother. 2003; 47:1842-52. [PubMed 12760857]



6. AIDSinfo Drugs Database. Emtricitabine. From the US Department of Health and Human Services HIV/AIDS Information Services (AIDSinfo) web site. Accessed 7 Oct 2003.



7. Gish RG, Leung NWY, Wright TL et al. Dose range study of pharmacokinetics, safety, and preliminary antiviral activity of emtricitabine in adults with hepatitis B virus infection. Antimicrob Agents Chemother. 2002; 46:1734-40. [IDIS 481640] [PubMed 12019083]



8. Gilead, Foster City, CA: Personal communication.



9. Saez-Llorens X, Violari A, Ndiweni D et al. Once daily emtricitabine (FTC) in HIV-infected pediatric patients with other antiretroviral agents. Poster presented at the 10th Conference on Retroviruses and Opportunistic Infections. Boston, MA: 2003 Feb 10-4.



10. Gilead Sciences, Inc. Truvada (emtricitabine and tenofovir disoproxil fumarate) tablet prescribing information. Foster City, CA; 2005 Jan.



11. Working Group on Antiretroviral Therapy and Medical Management of HIV-infected Children of the National Resource Center at the François-Xavier Bagnoud Center, Health Resources and Services Administration (HRSA), and National Institutes of Health (NIH). Guidelines for the use of antiretroviral agents in pediatric HIV infection (February 23, 2009). From the US Department of Health and Human Services HIV/AIDS Information Services (AIDSinfo) website.



12. Center for Disease Control and Prevention. Antiretroviral postexposure prophylaxis after sexual, injection-drug use, or other nonoccupational exposure to HIV in the United States: Recommendations from the U.S. Department of Health and Human Services. MMWR Recomm Rep. 2005; 54(No. RR-2):1-19.



13. Center for Disease Control and Prevention. Updated U.S. public health service guidelines for the management of occupational exposures to HIV and recommendations for postexposure prophylaxis. MMWR Recomm Rep. 2005; 54(No. RR-9):1-17.



14. Bristol-Myers Squibb and Gilead. Atripla (efavirenz 600 mg/emtricitabine 200mg /tenofovir disoproxil fumarate 300mg) tablets prescribing information. Foster City, CA; 2006 Jul.



15. Gallant JE, DeJesus E, Arribas JR et al. Tenofovir DF, emtricitabine, and efavirenz vs. zidovudine, lamivudine, and efavirenz for HIV. N Engl J Med. 2006; 354:251-60. [PubMed 16421366]



16. Perinatal HIV Guidelines Working Group. US Public Health Service Task Force recommendations for use of antiretroviral drugs in pregnant HIV-infected women for maternal health and interventions to reduce perinatal HIV-1 transmission in the United States (April 29, 2009). From the US Department of Health and Human Services HIV/AIDS Information Services (AIDSinfo) website.



17. Hammer SM, Saag MS, Schechter M et al. Treatment of adult HIV infection: 2006 recommendations of the International AIDS Society–USA panel. JAMA. 2006; 296:827-43. [PubMed 16905788]



18. Tibotec. Prezista (darunavir) prescribing information. Raritan, NJ; 2006 Jun.



19. Boehringer Ingelheim. Aptivus (tipranavir) capsules prescribing information. Ridgefield, CT; 2006 Jun 27.



20. Blum MR, Ndiweni D, Chittick G et al. Steady-state pharmacokinetic evaluation of emtricitabine in neonates exposed to HIV in utero. Poster presented at the 13th Conference on Retroviruses and Opportunistic Infections. Denver, CO: 2006 Feb 5-9.



More Emtriva resources


  • Emtriva Side Effects (in more detail)
  • Emtriva Use in Pregnancy & Breastfeeding
  • Drug Images
  • Emtriva Drug Interactions
  • Emtriva Support Group
  • 0 Reviews for Emtriva - Add your own review/rating


  • Emtriva Prescribing Information (FDA)

  • Emtriva Consumer Overview

  • Emtriva Advanced Consumer (Micromedex) - Includes Dosage Information

  • Emtriva MedFacts Consumer Leaflet (Wolters Kluwer)

  • Emtricitabine Professional Patient Advice (Wolters Kluwer)



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