Active Substance: abacavir / lamivudine
Common Name: abacavir / lamivudine
ATC Code: J05AR02
Marketing Authorisation Holder: ViiV Healthcare UK Limited  
Active Substance: abacavir / lamivudine
Status: Authorised
Authorisation Date: 2004-12-17
Therapeutic Area: HIV Infections
Pharmacotherapeutic Group: Antivirals for treatment of HIV infections, combinations

Therapeutic Indication

Kivexa is a fixed-dose combination of two nucleoside analogues (abacavir and lamivudine). It is indicated in antiretroviral combination therapy for the treatment of human-immunodeficiency-virus (HIV) infection in adults and adolescents from 12 years of age.

Before initiating treatment with abacavir, screening for carriage of the HLA-B*5701 allele should be performed in any HIV-infected patient, irrespective of racial origin. Screening is also recommended prior to re-initiation of abacavir in patients of unknown HLA-B*5701 status who have previously tolerated abacavir (see 'management after an interruption of Kivexa therapy'). Abacavir should not be used in patients known to carry the HLA-B*5701 allele, unless no other therapeutic option is available in these patients, based on the treatment history and resistance testing.

What is Kivexa?

Kivexa is a medicine that contains two active substances, abacavir (600 mg) and lamivudine (300 mg). It is available as orange capsule-shaped tablets.

What is Kivexa used for?

Kivexa is used in combination with at least one other antiviral medicine to treat patients over 12 years old who are infected with human immunodeficiency virus (HIV), the virus that causes acquired immune deficiency syndrome (AIDS).

The medicine can only be obtained with a prescription.

How is Kivexa used?

Kivexa should be prescribed by a doctor who has experience in the management of HIV infection.

Before starting treatment with Kivexa, 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 Kivexa if there are no other treatment options. This test is also recommended in patients who have tolerated abacavir in the past and who are about to start taking it again.

Kivexa is taken as one tablet once a day. It should only be given to patients who weigh over 40 kg. Patients who need to adjust the dose of abacavir or lamivudine should take the medicines separately.

Patients who take Kivexa must be given the special alert card that summarises the key safety information about the medicine.

How does Kivexa work?

Both active substances in Kivexa, abacavir and lamivudine, are nucleoside reverse-transcriptase inhibitors (NRTIs). They both 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. Kivexa, 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. Kivexa 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 available in the European Union (EU) since the late 1990s: abacavir has been authorised as Ziagen since 1999, and lamivudine has been authorised as Epivir since 1996.

How has Kivexa been studied?

Kivexa has been studied in three main studies involving a total of 1,230 patients. At the time of Kivexa’s authorisation, abacavir was authorised at a dose of 300 mg twice a day. Therefore, the studies compared abacavir taken at a dose of 600 mg once a day and at a dose of 300 mg twice a day, in combination with lamivudine and one or two other antiviral medicines. Two studies used the active substances taken as separate medicines, while the third used a combination tablet for the once-daily dose. The main measure of effectiveness was the change in the level of HIV in the blood (viral load) after 24 or 48 weeks of treatment.

What benefit has Kivexa shown during the study?

Both doses of abacavir, taken in combination with lamivudine and other antiviral medicines, were equally effective in reducing viral loads. In the first study, 66% of the patients taking abacavir once a day had viral loads below 50 copies/ml after 48 weeks (253 out of 384), compared with 68% of the patients taking it twice a day (261 out of 386). The combination tablet taken once a day was also as effective as the medicines taken separately twice a day in reducing viral loads over 24 weeks of treatment.

What is the risk associated with Kivexa?

The most common side effects with Kivexa (seen in between 1 and 10 patients in 100) are hypersensitivity (allergic reactions), rash, nausea (feeling sick), vomiting, diarrhoea, abdominal pain (stomach ache), headache, arthralgia (joint pain), muscle disorders, cough, nasal symptoms (nose problems, such as irritation and runny nose), fever, lethargy (lack of energy), fatigue (tiredness), insomnia (difficulty sleeping), malaise (feeling unwell), loss of appetite and alopecia (hair loss). For the full list of all side effects reported with Kivexa, see the package leaflet.

Hypersensitivity reactions occur in about 3% of patients taking Kivexa, 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, dyspnoea (difficulty breathing), cough, lethargy, malaise, headache, signs of liver damage in the blood and myalgia (muscle pain). Patients treated with Kivexa receive a card detailing these symptoms so that they are aware of them, and must contact their doctor immediately if they develop a reaction. For more information, see the package leaflet.

Kivexa should not be used in people who may be hypersensitive (allergic) to lamivudine, abacavir or any of the other ingredients. It must not be used in patients who have severe problems with their liver.

As with other anti-HIV medicines, patients taking Kivexa 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 Kivexa. As with all other NRTIs, Kivexa may also cause lactic acidosis (a build-up of lactic acid in the body) and, in the babies of mothers taking Kivexa during pregnancy, mitochondrial dysfunction (damage to the energy-producing components within cells that can cause problems in the blood).

Why has Kivexa been approved?

The CHMP decided that Kivexa’s benefits are greater than its risks and recommended that it be given marketing authorisation.

Other information about Kivexa

The European Commission granted a marketing authorisation valid throughout the EU for Kivexa on 17 December 2004. The marketing-authorisation holder is ViiV Healthcare UK Limited. After five years, the marketing authorisation was renewed for a further five years.

Source: European Medicines Agency

Disclaimer: Every effort has been made to ensure that the information provided here is accurate, up-to-date and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. This information has been compiled for use by healthcare practitioners and consumers in the United States. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate that the drug or combination is safe, effective or appropriate for any given patient. If you have questions about the substances you are taking, check with your doctor, nurse or pharmacist.