|Tenofovir disoproxil fumarate||Nucleotide analogue reverse transcriptase inhibitor|
|Emtricitabine||Nucleoside reverse transcriptase inhibitor|
|Pregnancy cat.||B (US)|
|Legal status||POM (UK) ℞-only (US)|
| (what is this?)
Tenofovir/emtricitabine, trademark Truvada by Gilead Sciences, is a fixed-dose combination of two antiretroviral drugs used for the treatment of HIV. It consists of 300 milligrams of tenofovir and 200 milligrams of emtricitabine.
The drug has been examined for use as a pre-exposure prophylaxis against HIV infection. A Cochrane review found that both tenofovir alone, as well as the tenofovir/emtricitabine combination, significantly decreased the risk of contracting HIV. The Food and Drug Administration approved it for prophylactic use on July 16, 2012. It is estimated that daily intake of Truvada achieves a 99% of risk reduction of contracting HIV in high risk individuals.
Clinical studies 
The HEAT study (randomized, double-blind, placebo-matched, multicentre) showed that once-daily emtricitabine/tenofovir plus lopinavir/ritonavir or boosted atazanavir or efavirenz were effective in the initial treatment of patients with HIV-1 infection (with screening plasma HIV-1 RNA levels of ≥1,000,000 copies/mL in ACTG 5202).
In other randomized trials, emtricitabine/tenofovir DF 200 mg/300 mg once daily was an effective backbone for boosted protease inhibitor (PI)-based regimens in the initial treatment of HIV-1 infection.
TRUVADA should not be taken by patients with an unknown or a positive HIV-1 form of the disease to treat pre-exposure prophylaxis. Patients who are infected with HIV should use TRUVADA only in combination with other antiretroviral medications.
Drug Interactions 
When tenofovir is coadministered with didanosine, the concentration of didanosine increases, and may lead to didanosine toxicity which may result in complications such as pancreatitis and neuropathy. If authorised, the dose of didanosine may be reduced or discontinued completely.
The coadministration of tenofovir and atazanavir results in decreased concentrations of atazanavir and increased concentrations of tenofovir. Atazanavir may be taken with TRUVADA only with ritonavir and must be monitored for tenofovir toxicity.
The coadministration of tenofovir and lopinavir/ritonavir increases the concentration of tenofovir and must be monitored for tenofovir toxicity.
- Okwundu CI, Uthman OA, Okoromah CAN (2012). "Antiretroviral pre-exposure prophylaxis (PrEP) for preventing HIV in high-risk individuals". In Okwundu, Charles I. Cochrane Database Syst Rev 7 (7): CD007189. doi:10.1002/14651858.CD007189.pub3. PMID 22786505.
- "FDA approves first pill to help prevent HIV". Seattle Times. 16 July 2012.
- "PK Modeling of Daily TDF/FTC (Truvada) Provides Close to 100% Protection Against HIV Infection". April 2012.
- MedicineNet.com. http://www.medicinenet.com/emtricitabine-tenofovir-oral/article.htm
- Perry CM (2009). "Emtricitabine/tenofovir disoproxil fumarate: in combination with a protease inhibitor in HIV-1 infection". Drugs 69 (7): 843–57. doi:10.2165/00003495-200969070-00005. PMID 19441871.
- Cohen J (December 2010). "HIV/AIDS clinical trials. A powerful and perplexing new HIV prevention tool". Science 330 (6009): 1298–9. doi:10.1126/science.330.6009.1298. PMID 21127220.
- Truvada 2012, p. 1.
- Truvada 2012, p. 2.
- Truvada [package insert]. Foster City, CA: Gilead Sciences, Inc.; 2012.