Emtricitabine/tenofovir, sold under the brand name Truvada among others, is a fixed-dose combination

antiretroviral medication Antiviral drugs are a class of medication used for treating viral infections. Most antivirals target specific viruses, while a broad-spectrum antiviral is effective against a wide range of viruses. Unlike most antibiotics, antiviral drugs do n ...

used to treat and prevent

HIV/AIDS Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual ...

. It contains the antiretroviral medications

emtricitabine Emtricitabine (commonly called FTC, systematic name 2',3'-dideoxy-5-fluoro-3'-thiacytidine), with trade name Emtriva (formerly Coviracil), is a nucleoside reverse-transcriptase inhibitor (NRTI) for the prevention and treatment of HIV infection i ...

and

tenofovir disoproxil Tenofovir disoproxil, sold under the trade name Viread among others, is a medication used to treat chronic hepatitis B and to prevent and treat HIV/AIDS. It is generally recommended for use with other antiretrovirals. It may be used for preven ...

. For treatment, it must be used in combination with other

s. For prevention before exposure, in those who are at high risk, it is recommended along with

safer sex In cryptography, SAFER (Secure And Fast Encryption Routine) is the name of a family of block ciphers designed primarily by James Massey (one of the designers of IDEA) on behalf of Cylink Corporation. The early SAFER K and SAFER SK designs share t ...

practices. It does not cure HIV/AIDS. Emtricitabine/tenofovir is taken

by mouth Oral administration is a route of administration where a substance is taken through the mouth. Per os abbreviated to P.O. is sometimes used as a direction for medication to be taken orally. Many medications are taken orally because they are i ...

. Common side effects include headache, tiredness, trouble sleeping, abdominal pain, weight loss, and rash. Serious side effects may include

high blood lactate levels Lactic acidosis is a medical condition characterized by a build-up of lactate (especially -lactate) in the body, with formation of an excessively low pH in the bloodstream. It is a form of metabolic acidosis, in which excessive acid accumulates ...

and enlargement of the liver. Use of this medication during

pregnancy Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins. Pregnancy usually occurs by sexual intercourse, but ca ...

does not appear to harm the baby, but has not been well studied. Emtricitabine/tenofovir was approved for medical use in the United States in 2004. It is on the

World Health Organization's List of Essential Medicines The WHO Model List of Essential Medicines (aka Essential Medicines List or EML), published by the World Health Organization (WHO), contains the medications considered to be most effective and safe to meet the most important needs in a health ...

. In the United States, emtricitabine/tenofovir was under patent until 2020, but is now available as a generic worldwide. In 2020, it was the 278th most commonly prescribed medication in the United States, with more than 1million prescriptions.

Medical uses

Emtricitabine/tenofovir is used both to treat and to prevent HIV/AIDS. The U.S.

National Institutes of Health The National Institutes of Health, commonly referred to as NIH (with each letter pronounced individually), is the primary agency of the United States government responsible for biomedical and public health research. It was founded in the late ...

(NIH) recommends antiretroviral therapy (ART) for all people with HIV/AIDS.

HIV prevention

The Centers for Disease Control and Prevention (CDC) recommends the use of emtricitabine/tenofovir for

pre-exposure prophylaxis Pre-exposure prophylaxis (PrEP) is the use of medications to prevent the spread of disease in people who have not yet been exposed to a disease-causing agent, usually a virus. The term typically refers to the use of antiviral drugs as a strate ...

(PrEP) for uninfected, HIV-1 negative individuals that may be at risk for HIV-1 infection. A Cochrane

systematic review A systematic review is a Literature review, scholarly synthesis of the evidence on a clearly presented topic using critical methods to identify, define and assess research on the topic. A systematic review extracts and interprets data from publ ...

found a 51%

relative risk reduction In epidemiology, the relative risk reduction (RRR) or efficacy is the relative decrease in the risk In simple terms, risk is the possibility of something bad happening. Risk involves uncertainty about the effects/implications of an activity with ...

of contracting HIV with both tenofovir alone and the tenofovir/emtricitabine combination. A

JAMA ''The Journal of the American Medical Association'' (''JAMA'') is a peer-reviewed medical journal published 48 times a year by the American Medical Association. It publishes original research, reviews, and editorials covering all aspects of biom ...

systematic review found a similar relative risk reduction of 54% on average and greater reduction with greater adherence. It was approved for PrEP against HIV infection in the United States in 2012. The CDC recommends PrEP be considered for the following high-risk groups: * Individuals in an ongoing sexual relationship with an HIV-positive partner * Gay or bisexual men who either have had anal sex without a condom or been diagnosed with an STD in the past six months * Heterosexual men or women who do not regularly use condoms during sex with partners of unknown HIV status who are substantial risk * Injection of drugs in the last six months with sharing of equipment *

Serodiscordant A serodiscordant relationship, also known as mixed-status, is one where one partner is infected by HIV and the other is not. This contrasts with seroconcordant relationships, in which both partners are of the same HIV status. Serodiscordancy contri ...

heterosexual and homosexual partners. where one partner is HIV-positive and the other HIV-negative The consideration of utilizing emtricitabine/tenofovir as a reduction strategy involves discussion with a health professional who can help the patient navigate the benefits and risks. Patients are advised to discuss any history of bone issues, kidney issues, or hepatitis B infection with their health care provider. Effectiveness of PrEP for prevention of infection is reliant on an individual's ability to take the medication consistently. Emtricitabine/tenofovir is also used for HIV

post-exposure prophylaxis Post-exposure prophylaxis, also known as post-exposure prevention (PEP), is any preventive medical treatment started after exposure to a pathogen in order to prevent the infection from occurring. COVID-19 In 2021, the FDA has approved bamlanivi ...

. People who start taking emtricitabine/tenofovir see HIV reduction benefit up to 72 hours after starting, but the medicine must be taken for thirty days after a high-risk sexual event to ensure HIV transmission levels are optimally reduced. Truvada as PrEP should not be used for individuals that are positive for HIV-1.

HIV treatment

Emtricitabine/tenofovir has been approved in the United States as part of antiretroviral combination therapy for the treatment of

HIV-1 The subtypes of HIV include two major types, HIV type 1 (HIV-1) and HIV type 2 (HIV-2). HIV-1 is related to viruses found in chimpanzees and gorillas living in western Africa, while HIV-2 viruses are related to viruses found in the sooty mangabey ...

. The combination therapy is suggested as one of the options for adults who have not received any prior treatment for HIV infection.

Hepatitis B

Both emtricitabine and tenofovir are indicated for the treatment of

hepatitis B Hepatitis B is an infectious disease caused by the ''Hepatitis B virus'' (HBV) that affects the liver; it is a type of viral hepatitis. It can cause both acute and chronic infection. Many people have no symptoms during an initial infection. Fo ...

, with the added benefit that they can target HIV for those with co-infection. Emtricitabine/tenofovir may also be considered for some antiviral resistant

infections.

Pregnancy and breastfeeding

In the United States, it is recommend that all pregnant HIV-infected women start

antiretroviral therapy The management of HIV/AIDS normally includes the use of multiple Antiviral drug, antiretroviral drugs as a strategy to control HIV/AIDS, HIV infection. There are several classes of antiretroviral agents that act on different stages of the HIV life- ...

(ART) as early in pregnancy as possible to reduce risk of transmission. ART generally does not increase risk of birth defects with exception of

dolutegravir Dolutegravir (DTG), sold under the brand name Tivicay, is an antiretroviral medication used, together with other medication, to treat HIV/AIDS. It may also be used, as part of post exposure prophylaxis, to prevent HIV infection following potentia ...

, which is not recommended during first trimester of pregnancy only due to potential risk of

neural tube defect Neural tube defects (NTDs) are a group of birth defects in which an opening in the spine or cranium remains from early in human development. In the third week of pregnancy called gastrulation, specialized cells on the dorsal side of the embryo ...

s. Emtricitabine/tenofovir is secreted in breast milk. In developed countries, HIV-infected mothers are generally recommended to not breastfeed due to slight risk of mother-to-children HIV transmission. In developing countries, where avoiding breastfeeding may not be an option, the World Health Organization recommends a triple drug regimen of tenofovir, efavirenz, and either lamivudine or emtricitabine.

Side effects

Emtricitabine/tenofovir is generally well tolerated. Some of its side effects include: * Rare:

lactic acidosis Lactic acidosis is a medical condition characterized by a build-up of lactate (especially -lactate) in the body, with formation of an excessively low pH in the bloodstream. It is a form of metabolic acidosis, in which excessive acid accumulates ...

, liver dysfunction, worsening of

infection * Common: headache, abdominal pain, decreased weight, nausea, diarrhea, and decreased bone density Fat redistribution and accumulation (

lipodystrophy Lipodystrophy syndromes are a group of genetic or acquired disorders in which the body is unable to produce and maintain healthy fat tissue. The medical condition is characterized by abnormal or degenerative conditions of the body's adipose tissue. ...

) has been observed in people receiving antiretroviral therapy, including fat reductions in the face, limbs, and buttocks and increases in

visceral fat Adipose tissue, body fat, or simply fat is a loose connective tissue composed mostly of adipocytes. In addition to adipocytes, adipose tissue contains the stromal vascular fraction (SVF) of cells including preadipocytes, fibroblasts, vascular e ...

of the abdomen and accumulations in the upper back. When used as pre-exposure prophylaxis (PrEP) this effect may not be present. Weight changes have however been linked to the medication.

Drug interactions

Other drugs with adverse reactions include

dabigatran etexilate Dabigatran, sold under the brand name Pradaxa among others, is an anticoagulant used to treat and prevent venous thromboembolism, blood clots and to prevent stroke in people with atrial fibrillation. Specifically it is used to prevent blood clo ...

lamivudine Lamivudine, commonly called 3TC, is an antiretroviral medication used to prevent and treat HIV/AIDS. It is also used to treat chronic hepatitis B when other options are not possible. It is effective against both HIV-1 and HIV-2. It is typicall ...

, and

vincristine Vincristine, also known as leurocristine and marketed under the brand name Oncovin among others, is a chemotherapy medication used to treat a number of types of cancer. This includes acute lymphocytic leukemia, acute myeloid leukemia, Hodgkin's ...

. Dabigatran etexilate used with

p-glycoprotein P-glycoprotein 1 (permeability glycoprotein, abbreviated as P-gp or Pgp) also known as multidrug resistance protein 1 (MDR1) or ATP-binding cassette sub-family B member 1 (ABCB1) or cluster of differentiation 243 (CD243) is an important protein ...

inducers require monitoring of decreased levels and effects of dabigatran. Lamivudine may increase the adverse or toxic effect of emtricitabine. Vincristine used with P-glycoprotein/ABCB1 inducers can decrease the serum concentration of vincristine.

Society and culture

The patent for the drug combination is owned by

Gilead Sciences Gilead Sciences, Inc. () is an American biopharmaceutical company headquartered in Foster City, California, that focuses on researching and developing antiviral drugs used in the treatment of HIV/AIDS, hepatitis B, hepatitis C, influenza, and CO ...

in some regions. The

European patent The European Patent Convention (EPC), also known as the Convention on the Grant of European Patents of 5 October 1973, is a multilateral treaty instituting the European Patent Organisation and providing an autonomous legal system according to w ...

EP0915894B1 expired in July 2018, Gilead Sciences wished the patent to be extended, however "four rival labs—Teva, Accord Healthcare, Lupin and Mylan—had sought to have that overturned in the courts in Britain", the High Court of England and Wales invalidated Gilead's patent, however the company appealed and the UK referred the case to the

European Court of Justice The European Court of Justice (ECJ, french: Cour de Justice européenne), formally just the Court of Justice, is the supreme court of the European Union in matters of European Union law. As a part of the Court of Justice of the European Un ...

who refused to extend the patent. An Irish court rejected an injunction request to prevent the launch of generic Emtricitabine/tenofovir prior to the resolution of the case. Despite the expiration of the Gilead Sciences patent, as of 2021, there are still widespread challenges to the availability and uptake of generic PrEP throughout Europe. In 2019, Gilead Sciences challenged patents held by the United States for the drug combination. In the United States, most healthcare plans are required to cover PrEP without any copay or other

cost sharing In health care, cost sharing occurs when patients pay for a portion of health care costs not covered by health insurance. The "out-of-pocket" payment varies among healthcare plans and depends on whether or not the patient chooses to use a healthca ...

. This is due to a

United States Preventive Services Task Force The United States Preventive Services Task Force (USPSTF) is "an independent panel of experts in primary care and prevention that systematically reviews the evidence of effectiveness and develops recommendations for clinical preventive services". ...

recommendation that gave PrEP a grade A rating. Under the

Affordable Care Act The Affordable Care Act (ACA), formally known as the Patient Protection and Affordable Care Act and colloquially known as Obamacare, is a landmark U.S. federal statute enacted by the 111th United States Congress and signed into law by Presid ...

, this recommendation requires all non-grandfathered private health plans to cover PrEP without cost sharing. In the United Kingdom, PrEP is widely available to all at risk groups following the Department for Health and Social Care's decision to make it available across England from 2020. Wales, Scotland, and Northern Ireland made it available in 2017 and 2018.

References

External links

* {{DEFAULTSORT:Emtricitabine Tenofovir Disoproxil Fixed dose combination (antiretroviral) Gilead Sciences Hepatotoxins Pre-exposure prophylaxis Wikipedia medicine articles ready to translate World Health Organization essential medicines