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 BRAND NAMES
- Canada: Trizivir Product Monograph/Monographie
- Europe: Trizivir EPAR summary for the public, Prescribing Information
- International: Trizivir
- U.S.: Trizivir PI
 MECHANISM OF ACTION
All three active substances in Trizivir, abacavir, lamivudine, and zidovudine, are nucleoside reverse transcriptase inhibitors (NRTIs). They all 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. Trizivir reduces the amount of HIV in the blood and keeps it at a low level. Trizivir 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.
Trizivir is used to treat adults who are infected with human immunodeficiency virus (HIV), the virus that causes acquired immune deficiency syndrome (AIDS). It is used to replace treatment with the three active substances (abacavir, lamivudine and zidovudine) taken separately at doses similar to those in Trizivir. Patients should have already been taking the three active substances separately for at least six to eight weeks before switching to Trizivir. Before prescribing Trizivir, doctors should consider the expected improved ability of the patient to stick to their treatment, the expected effectiveness of the medicine, and the risks associated with the active substances.
In patients with high levels of HIV in the blood (above 100,000 copies/ml), the choice of treatment requires special consideration.
Overall, since certain other combination treatments could be more effective, the use of Trizivir should only be considered under special circumstances such as co-infection with tuberculosis (as other HIV treatments can interact with the medicines being taken by the patient).
Adults and Adolescent Patients > 40 kg, one tablet (Abacavir:300mg/Lamivudine:150mg/Zidovudine:300mg) twice daily with or without food.
Before starting treatment with Trizivir, all patients should have a test to find out if they have a gene called ‘HLA-B (type 5701)’. Patients with this gene are at an increased risk of having an allergic reaction to abacavir, so they should only take Trizivir if there are no other treatment options. This test is also recommended in patients who have tolerated abacavir in the past and are about to start taking it again.
If patients need to stop taking abacavir, lamivudine or zidovudine, or need to take different doses because of problems with their kidneys, liver or blood, they will need to take medicines containing abacavir, lamivudine or zidovudine separately.
- Trizivir must not be used in patients who are hypersensitive (allergic) to lamivudine, zidovudine, abacavir or any of the other ingredients.
- Hepatic impairment: Trizivir must not be used in patients who have problems with their liver or who have kidney failure. Because it contains zidovudine, Trizivir must not be used by patients with low neutrophil counts (low levels of a type of white blood cell) or anaemia (low red blood cell counts).
 SIDE EFFECTS
Most commonly reported with Trizivir: Nausea, headache, malaise and fatigue.
Hypersensitivity reactions (allergic reactions) occur in about 3% of patients taking Trizivir, usually within the first six weeks of treatment, and can be life-threatening. The risk of hypersensitivity is higher in patients who have the HLA-B (type 5701) gene. Symptoms almost always include fever or rash, but also very commonly include nausea, vomiting, diarrhoea, abdominal pain (stomach ache), headache, signs of liver damage in the blood, myalgia (muscle pain), dyspnoea (difficulty breathing), cough, lethargy (lack of energy) and malaise (feeling unwell).