| Manufacturer || Gilead Sciences Int. Ltd.
| Disease || HIV / AIDS
| Indication || HIV-1 infection or prevention (PrEP)
| Mode of Action || Antiviral
| Approval Status || EMA approved (EU); FDA approved (USA); TGA approved (AUS)
| Strength || 200 mg / 245 mg
Who is emtricitabine / tenofovir disoproxil for?
Truvada (emtricitabine / tenofovir disoproxil) is indicated for the treatment
of individuals infected with human immunodeficiency virus type 1 (HIV-1), a virus that causes acquired immune deficiency syndrome (AIDS). It is used in combination with at least one other antiviral medicine 
Truvada (emtricitabine / tenofovir disoproxil) is also indicated as ‘pre-exposure prophylaxis’ (PrEP)
to help prevent sexually transmitted HIV-1 infection in adults who are at high risk of being infected. It is recommended for use in combination with safer sex practices, such as the use of condoms 
, which may protect against other sexually transmitted infections (STIs) as well as against HIV infection. Truvada can be used for PrEP only in individuals who have been tested to be free of HIV infection. Individuals taking it to prevent HIV-1 infection should be tested at least every 3 months to make sure that they are free of HIV-1 
In the case of kidney dysfunction, Truvada should be used only if the potential benefits are considered to outweigh the potential risks. Prior to initiating Truvada for the treatment of HIV-1 infection or for use in pre-exposure prophylaxis, it is recommended that the kidney function is checked in all individuals, i.e. by calculating the creatinine clearance. In individuals without risk factors for renal disease, it is recommended that renal function (creatinine clearance and serum phosphate) is monitored after two to four weeks of use, after three months of use and every three to six months thereafter. In individuals at risk for renal disease more frequent monitoring of renal function is required 
Complete information about Truvada (emtricitabine / tenofovir disoproxil) dosage and administration can be found here 
The FDA standard dosage is:
- in adults and pediatric patients weighing more than or equal to 35 kg: one tablet 200 mg/ 300 mg of emtricitabine and tenofovir disoproxil fumerate once daily (equivalent to 200 mg emtricitabine/ 245 mg tenofovir disoproxil).
- in pediatric patients weighing greater than or equal to 17 kg and able to swallow a whole tablet: one low strength tablet (100 mg/150 mg, 133 mg/ 200 mg, or 167 mg/ 250 mg based on body weight) once daily .
The TGA standard dosage is:
- 1 tablet 200 mg emtricitabine/ 300 mg tenofovir disoproxil fumerate once daily  (equivalent to 200 mg emtricitabine/ 245 mg tenofovir disoproxil).
The EMA standard dosage in adults and adolescents aged 12 years and older is:
- 1 tablet 200 mg emtricitabine/ 245 mg tenofovir disoproxil once daily (equivalent to 200 mg emtricitabine/ 300 mg tenofovir disoproxil fumerate) .
The kidney function should be monitored in all patients. Patients using Truvada for PrEP should be tested for HIV infection every 3 months.
Consult your treating doctor for personalised dosing.
What is emtricitabine / tenofovir disoproxil and how does it work?
Truvada (emtricitabine / tenofovir disoproxil) is an antiviral medicine used in combination with at least one other antiviral medicine to treat adults infected with human immunodeficiency virus type 1 (HIV-1), a virus that causes acquired immune deficiency syndrome (AIDS) 
It is also used to help prevent sexually transmitted HIV-1 infection in adults who are at high risk of being infected (PrEP - pre-exposure prophylaxis). It is recommended for use in combination with safer sex practices, such as the use of condoms 
, which may protect against other sexually transmitted infections (STIs) as well as against HIV infection.
Each tablet of Truvada (emtricitabine / tenofovir disoproxil) contains two active substances, emtricitabine (200 mg) and tenofovir disoproxil (300 mg 
, 245 mg 
or other 
). Inside the body, tenofovir disoproxil is converted into the active substance tenofovir. Tenofovir and emtricitabine block the activity of the enzyme made by the virus to reproduce itself in the cells it has infected.
For the treatment
of HIV-1 infection, Truvada, taken in combination with at least one other antiviral medicine, reduces the amount of HIV in the blood and keeps it at a low level. It does not cure HIV infection or AIDS, but it can prevent damages to the immune system and the development of infections and diseases associated with AIDS 
For HIV-1 infection prevention (PrEP)
, it is expected that Truvada in the blood will stop the virus from multiplying and spreading from the site of infection in case the individual is exposed to the virus 
Both active substances have been widely authorised separately since the early 2000s 
What is emtricitabine / tenofovir disoproxil's approval status?
Truvada (emtricitabine / tenofovir disoproxil) was approved among others by:
- FDA on August 2, 2004 
- EMA (EU) February 21, 2005 
- TGA on September 22, 2005 
For the treatment of individuals infected with human immunodeficiency virus type 1 (HIV-1), in combination with at least one other antiviral medicine. Approximately 10 years later (2012 by the FDA 
, in 2016 by the EMA 
and TGA 
) the approval has been extended to the use as pre-exposure prophylaxis (PrEP) in combination with safer sex practices to reduce the risk of sexually acquired HIV-1 in adults at high risk.
The approvals of Truvada (emtricitabine / tenofovir disoproxil) for HIV-1
treatment were based on studies that compared emtricitabine and tenofovir disoproxil with other antiviral medicines in HIV-1-positive treatment-naive adults. The active substances in Truvada, emtricitabine and tenofovir disoproxil, were more effective than the comparator medicines in reducing the viral load 
The study GS-01-934 
compared the combination of emtricitabine and tenofovir disoproxil with the combination of lamivudine and zidovudine (other antiviral medicines) both taken with another antiviral medicine (efavirenz) by patients with HIV-1 infection. Eighty percent of the patients (total of 511) taking emtricitabine and tenofovir disoproxil achieved and maintained viral loads below 50 HIV-1 copies/ml by 48 weeks, compared with 70 % of the patients taking the comparator medicines 
The approvals of Truvada (emtricitabine / tenofovir disoproxil) as pre-exposure prophylaxis (PrEP)
were based on two main studies which evaluated the addition of emtricitabine / tenofovir disoproxil to standard preventative measures for pre-exposure prophylaxis. This was done by comparing emtricitabine / tenofovir disoproxil with placebo in adults at high risk of sexually transmitted HIV-1 infection. Emtricitabine / tenofovir disoproxil resulted more effective than placebo for preventing HIV-1 infection. In both studies the level of protection depended on how well individuals adhered to the treatment program 
Study iPrEx involved 2499 HIV-seronegative individuals with evidence of high-risk behaviour for HIV-1 infection 
. In total, the study lasted 4,237 person-years (a person-year is a measurement combining the number of persons and their time contribution in a study 
).Of the 1,224 people in the emtricitabine/tenofovir disoproxil arm 3.9 % tested positive for HIV-1 infection compared with 6.8 % individuals taking placebo 
The second study (Partner PrEP) involved over 4,758 heterosexual couples with discordant HIV-1 infection status 
. Of the individuals taking Truvada, 0.8 % tested positive for HIV-1 infection over 1 year compared with 3.3 % of those taking placebo 
The most common adverse reactions were nausea and diarrhoea 
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