Active Substance: emtricitabine / tenofovir disoproxil fumarate
Common Name: emtricitabine / tenofovir disoproxil
ATC Code: J05AR03
Marketing Authorisation Holder: Gilead Sciences International Limited
Active Substance: emtricitabine / tenofovir disoproxil fumarate
Authorisation Date: 2005-02-21
Therapeutic Area: HIV Infections
Pharmacotherapeutic Group: Antivirals for treatment of HIV infections, combinations
Truvada is a fixed dose combination of emtricitabine and tenofovir disoproxil fumarate. It is indicated in antiretroviral combination therapy for the treatment of HIV-1 infected adults.
The demonstration of the benefit of the combination emtricitabine and tenofovir disoproxil fumarate in antiretroviral therapy is based solely on studies performed in treatment-naive patients.
What is Truvada?
Truvada is a medicine that contains two active substances, emtricitabine (200 mg) and tenofovir disoproxil (245 mg). It is available as blue capsule-shaped tablets.
What is Truvada used for?
Truvada is 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).
The medicine can only be obtained with a prescription.
How is Truvada used?
Treatment with Truvada should be started by a doctor who has experience in the management of HIV infection.
The recommended dose of Truvada is one tablet once a day, taken with food. The tablets may need to be taken less frequently in patients with kidney disease. In exceptional cases, patients who have difficulty swallowing can crush the tablet and mix it in about 100 ml of water, orange juice or grape juice before taking it immediately. If patients need to stop taking emtricitabine or tenofovir, or need to take different doses, they will need to take medicines containing emtricitabine or tenofovir disoproxil separately. For more information, see the Package Leaflet.
How does Truvada work?
Truvada contains two active substances: emtricitabine, which is a nucleoside reverse transcriptase inhibitor; and tenofovir disoproxil, which is a ‘prodrug’ of tenofovir. This means that it is converted into tenofovir in the body. Tenofovir is a nucleotide reverse transcriptase inhibitor. Both groups of medicines are known as NRTIs.
Both emtricitabine and tenofovir work in similar ways by blocking the activity of reverse transcriptase, an enzyme produced by HIV that allows it to infect cells and make more viruses. 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. Truvada does not cure HIV infection or AIDS, but it may delay the damage to the immune system and the development of infections and diseases associated with AIDS.
Both active substances have been authorised in the European Union (EU) since the early 2000s: emtricitabine was authorised as Emtriva in 2003, and tenofovir disoproxil was authorised as Viread in 2002.
How has Truvada been studied?
There have been two main studies, which examined the effects of Truvada’s active substances, emtricitabine and tenofovir disoproxil, in adults infected with HIV-1 who had not been treated before. The first study compared the combination of emtricitabine and tenofovir disoproxil with the combination of lamivudine and zidovudine (other antiviral medicines), both taken in combination with efavirenz (another antiviral medicine) in 487 patients. The second study examined the effects of emtricitabine and tenofovir disoproxil, taken with lopinavir and ritonavir (other antiviral medicines) in 196 patients. The main measure of effectiveness was the proportion of patients whose HIV levels in the blood (viral loads) had fallen to below 400 or 50 copies per millilitre and were maintained below these levels until the 48th week of treatment.
The company also carried out studies to show that the active substances in the combined tablet are absorbed by the body in the same way as the two medicines given separately.
What benefit has Truvada shown during the studies?
Truvada’s active substances, taken in combination with other antiviral medicines, reduced viral loads in the majority of patients and were more effective than the comparator medicines. In the first study, 84% of the patients taking Truvada (206 out of 244) had achieved and maintained viral loads below 400 copies/ml by 48 weeks, compared with 73% of the patients taking the comparator medicines (177 out of 243). Around two thirds of the patients in the second study had achieved and maintained viral loads below 50 copies/ml after 48 weeks.
What is the risk associated with Truvada?
The most common side effects with Truvada (seen in more than 1 patient in 10) are hypophosphataemia (low levels of phosphates in the blood), headache, dizziness, diarrhoea, vomiting, nausea (feeling sick) and raised blood levels of creatine kinase (an enzyme found in muscles). For the full list of all side effects reported with Truvada, see the Package Leaflet.
Truvada should not be used in patients who may be hypersensitive (allergic) to emtricitabine, tenofovir disoproxil or any of the other ingredients.
As with other anti-HIV medicines, patients taking Truvada may be at risk of lipodystrophy (changes in the distribution of body fat), osteonecrosis (death of bone tissue) or immune reactivation syndrome (symptoms of infection caused by the recovering immune system). Patients who have problems with their liver (including hepatitis B or C infection) may be at an elevated risk of liver damage when taking Truvada. As with all other NRTIs, Truvada may also cause lactic acidosis (a build-up of lactic acid in the body) and, in the babies of mothers taking Truvada during pregnancy, mitochondrial dysfunction (damage to the energy-producing components within cells than can cause problems in the blood).
Why has Truvada been approved?
The Committee for Medicinal Products for Human Use (CHMP) noted that the benefit of Truvada has only been shown in patients who have not taken HIV treatment before, but that the simplified dosing regimen offered by the combination tablet taken once a day may help patients to stick to their treatment. The Committee concluded that Truvada’s benefits are greater than its risks and recommended that it be given marketing authorisation.
Other information about Truvada
The European Commission granted a marketing authorisation valid throughout the EU for Truvada to Gilead Sciences International Limited on 21 February 2005. The marketing authorisation is valid for an unlimited period.
Source: European Medicines Agency
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