Tenofovir

drugbox
IUPAC_name = 1-(6-aminopurin-9-yl) propan-2-yloxymethylphosphonic acid




imagename = Tenofovir
and tenofovir disoproxil fumarate
width = 200px
CAS_number = 147127-20-6
ATC_prefix = J05
ATC_suffix = AF07
PubChem = 464205
DrugBank = APRD01248
C = 9 |H = 14 |N = 5 |O = 4 |P = 1
molecular_weight = 287.213 g/mol
bioavailability = 25%
protein_bound = < 1%
metabolism =
elimination_half-life = 17 hours
excretion = Renal
pregnancy_category = B (U.S.)
legal_status = ℞-only (U.S.), POM (UK)
routes_of_administration = Oral

Tenofovir disoproxil fumarate (TDF or PMPA [cite journal | title=Post-exposure prophylaxis for SIV revisited: Animal model for HIV infection | author=Emau P, Jiang Y, Agy MB, "et al." | journal=AIDS Res Ther | year=2006 | volume=3 | pages=29 | doi=10.1186/1742-6405-3-29 ] ), marketed by Gilead Sciences under the trade name Viread, belongs to a class of antiretroviral drugs known as nucleotide analogue reverse transcriptase inhibitors (nRTIs), which block reverse transcriptase, an enzyme crucial to viral production in HIV-infected people.

Tenofovir is also available in a fixed-dose combination with emtricitabine in a product with the brand name Truvada for once-a-day dosing. (Emtricitabine is marketed as a single-compound product called Emtriva, also by Gilead.) Atripla, a fixed-dose triple combination of tenofovir, emtricitabine and efavirenz, was approved by the FDA on 12 July 2006 and is now available, providing a single daily dose for the treatment of HIV.

Tenofovir is indicated in combination with other antiretroviral agents for the treatment of HIV-1 infection in adults. This indication is based on analyses of plasma HIV-1 RNA levels and CD4 cell counts in controlled studies of tenofovir in treatment-naïve and treatment-experienced adults. There are no study results demonstrating the effect of tenofovir on the clinical progression of HIV.

Tenofovir can cause acute renal failure, fanconi syndrome, proteinuria, tubular necrosis. These side effects are due to accumulation of drug in proximal tubule. Tenofovir can interact with didanosine by increasing didanosine's concentration. It also decreases the concentration of Atazanavir sulfate.

History

Tenofovir was discovered through a collaborative research effort between Antonín Holý at the Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic (IOCB) in Prague, and Erik DeClercq, Rega Institute for Medical Research, Catholic University of Leuven, Belgium.

Tenofovir was approved by the U.S. Food and Drug Administration (FDA) on October 26, 2001 for the treatment of HIV, and on August 11, 2008 for the treatment of chronic hepatitis B [ [http://www.fda.gov/cder/foi/appletter/2008/021356s025ltr.pdf FDA letter of approval (regarding treatment of hepatitis B)] ] [ [http://online.wsj.com/article/SB121849463154631469.html?mod=us_business_whats_news FDA Clears Viread for Hepatitis B] ] .

Adverse Effects

The most common side effects associated with tenofovir include nausea, vomiting, diarrhea, and asthenia. Less frequent side effects include hepatotoxicity, abdominal pain, and flatulence. [ cite book
title = USPDI
publisher = Thompson
date = 2005
pages = 2741&ndash;2 ] Tenofovir has also been implicated in causing renal toxicity, particularly at elevated concentrations. [cite web
title = Viread Prescribing Guidelines
publisher = FDA
date = March 2006
url = http://www.fda.gov/cder/foi/label/2006/021356s016lbl.pdf
accessdate = 2007-02-12]

HIV risk reduction

A 2006 trial by Family Health International gave either Viread or a placebo to 936 high-risk women in Cameroon, Ghana and Nigeria. While the results show signs that the Viread group contracted HIV at a reduced rate, the researchers cautioned against drawing conclusions from the study because the sample size was so small. [cite web
title = Tenofovir Use Safe for Uninfected, West African Women at Risk of HIV Infection
publisher = Family Health International
date = 2006-08-17
url = http://www.fhi.org/en/AboutFHI/Media/Releases/TenofovirSafe081706.htm
accessdate = 2007-06-01] [cite web
title = Additional Studies Needed to Assess Effectiveness of Tenofovir for Prevention
publisher = Family Health International
url = http://www.fhi.org/en/RH/Pubs/Briefs/HIVprevTrials/fhitdfstudy.htm
accessdate = 2007-06-01]

External links

* [http://www.gileadhiv.com/320Viread.aspx Official Viread website]

References