Active Substance: atazanavir sulphate
Common Name: atazanavir sulphate
ATC Code: J05AE08
Marketing Authorisation Holder: Bristol-Myers Squibb Pharma EEIG
Active Substance: atazanavir sulphate
Authorisation Date: 2004-03-02
Therapeutic Area: HIV Infections
Pharmacotherapeutic Group: Antivirals for systemic use
Reyataz capsules, co-administered with low-dose ritonavir, are indicated for the treatment of HIV‑1-infected adults and paediatric patients 6 years of age and older in combination with other antiretroviral medicinal products.
Based on available virological and clinical data from adult patients, no benefit is expected in patients with strains resistant to multiple protease inhibitors (≥4 protease inhibitor mutations). There are very limited data available from children aged 6 to less than 18 years.
The choice of Reyataz in treatment-experienced adult and paediatric patients should be based on individual viral resistance testing and the patient’s treatment history.
What is Reyataz?
Reyataz is an antiviral medicine that contains the active substance atazanavir. It is available as capsules (100 mg, 150 mg, 200 mg and 300 mg).
What is Reyataz used for?
Reyataz is used together with low-dose ritonavir and other antiviral medicines to treat patients aged six years and over who are infected with human immunodeficiency virus type 1 (HIV‑1), a virus that causes acquired immune deficiency syndrome (AIDS).
Doctors should only prescribe Reyataz to patients who have received anti‑HIV medicines before after they have looked at which medicines the patient has taken and carried out tests to establish that the virus is likely to respond to Reyataz. Based on the information available in adults, the medicine is not expected to work in patients in whom many medicines in the same class as Reyataz (protease inhibitors) do not work.
The medicine can only be obtained with a prescription.
How is Reyataz used?
Treatment with Reyataz should be started by a doctor who has experience in the treatment of HIV infection.
For adults (aged 18 years or over), the recommended dose is 300 mg once a day. In younger patients, the dose of Reyataz depends on body weight. There is no suitable dose for patients weighing less than 15 kg. Each dose must be taken with food. Reyataz is normally given with ritonavir to boost its action although in specific cases doctors can consider stopping ritonavir.
How does Reyataz work?
The active substance in Reyataz, atazanavir, is a protease inhibitor. It blocks an enzyme called protease, which is involved in the reproduction of HIV. When the enzyme is blocked, the virus does not reproduce normally, slowing down the spread of infection. Ritonavir, another protease inhibitor, is normally recommended to be given at the same time as a ‘booster’. It slows down the rate at which atazanavir is broken down, increasing the levels of atazanavir in the blood. This allows a lower dose of atazanavir to be used for the same antiviral effect. Reyataz, taken in combination with other antiviral medicines, reduces the amount of HIV in the blood and keeps it at a low level. Reyataz 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.
How has Reyataz been studied?
Reyataz has been assessed in four main studies involving patients aged 16 years and over. One study compared ritonavir-boosted Reyataz with ritonavir-boosted lopinavir (another antiviral medicine) in 883 patients who had not taken treatment for HIV infection before. The other three studies involved a total of 743 patients who had taken treatment for HIV infection before: the first two compared Reyataz, taken with saquinavir (another antiviral medicine) but without ritonavir, with ritonavir-boosted saquinavir or ritonavir-boosted lopinavir. The final study compared Reyataz plus either ritonavir or saquinavir with ritonavir-boosted lopinavir in 358 patients. The main measure of effectiveness was the change in the levels of HIV in the patients’ blood (viral load).
Reyataz capsules boosted with ritonavir have also been studied in 41 patients aged between six and 18 years. Around half of these patients had taken anti‑HIV treatment in the past. The study looked at the effect of the medicine on viral load and on the immune system, among other measures.
A further main study involved 172 patients who had achieved undetectable viral loads (below 50 copies/ml) after treatment with Reyataz and ritonavir. It compared continued treatment with either Reyataz without ritonavir or the boosted combination.
In all of the studies, the patients also took two nucleoside or nucleotide reverse transcriptase inhibitors (NRTIs, a type of antiviral medicine).
What benefit has Reyataz shown during the studies?
In patients who had not been treated before, ritonavir-boosted Reyataz was as effective as ritonavir-boosted lopinavir. At the start of the study, the patients’ viral loads were around 88,100 copies/ml, but after 48 weeks, 78% of the patients taking Reyataz (343 out of 440) had viral loads below 50 copies/ml, compared with 76% of those taking lopinavir (338 out of 443).
In patients who had been treated before, the results of the first study could not be interpreted, as a large number of patients left the study before its planned end. In the second study, ritonavir-boosted lopinavir caused a greater reduction in viral load than Reyataz taken without ritonavir after 24 weeks. In the third study, patients taking ritonavir-boosted Reyataz had similar falls in viral load after 24 and 48 weeks as those taking ritonavir-boosted lopinavir: they had fallen by around 99% after 48 weeks. This finding was maintained after 96 weeks.
In the patients aged between six and 18 years, 81% of those who had not taken anti‑HIV treatment in the past (13 out of 16) and 24% of those who had taken it in the past (6 out of 25) had viral loads below 50 copies/ml after 48 weeks. The patients also had improvements in their immune systems.
In the study in patients who had already achieved undetectable viral loads with ritonavir-boosted Reyataz, these were maintained in 68 of 87 patients (78%) who continued treatment with Reyataz without ritonavir, and in 64 of 85 (75%) who continued with the boosted combination.
What is the risk associated with Reyataz?
In adults, the most common side effects with Reyataz (seen in between 1 and 10 patients in 100) are headache, ocular icterus (yellowing of the eyes), vomiting, diarrhoea, abdominal pain (stomach ache), nausea (feeling sick), dyspepsia (heartburn), rash, lipodystrophy syndrome (changes in the distribution of body fat), fatigue (tiredness) and jaundice (yellowing of the skin and eyes associated with liver problems). In studies, side effects were similar in younger patients. For the full list of all side effects reported with Reyataz, see the package leaflet.
Reyataz must not be used in patients who have severe reductions in their liver function, who may be at increased risk of liver damage from the medicine; if given with ritonavir it must also not be used in patients with moderate reduction in liver function. In addition, Reyataz must not be given to patients taking rifampicin (used to treat tuberculosis), sildenafil (when this medicine is used to treat pulmonary arterial hypertension), St John’s wort (a herbal preparation used to treat depression) or medicines that are broken down in the body in the same way as Reyataz and are harmful at high levels in the blood. For the full list of restrictions with Reyataz see the package leaflet.
Why has Reyataz been approved?
The CHMP noted that Reyataz’s effectiveness had been shown in patients aged six years or over, although there is very limited information available from patients aged between six and 18 years. The Committee decided that Reyataz’s benefits are greater than its risks and recommended that it be given marketing authorisation.
What measures are being taken to ensure the safe and effective use of Reyataz?
A risk management plan has been developed to ensure that Reyataz is used as safely as possible. Based on this plan, safety information has been included in the summary of product characteristics and the package leaflet for Reyataz, including the appropriate precautions to be followed by healthcare professionals and patients.
Other information about Reyataz
The European Commission granted a marketing authorisation valid throughout the European Union for Reyataz on 2 March 2004.
For more information about treatment with Reyataz, read the package leaflet (also part of the EPAR) or contact your doctor or pharmacist.
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.