Active Substance: raltegravir
Common Name: raltegravir
ATC Code: J05AX08
Marketing Authorisation Holder: Merck Sharp & Dohme Ltd
Active Substance: raltegravir
Authorisation Date: 2007-12-20
Therapeutic Area: HIV Infections
Pharmacotherapeutic Group: Antivirals for systemic use
Isentress is indicated in combination with other anti-retroviral medicinal products for the treatment of human immunodeficiency virus (HIV 1) infection in adults, adolescents, children, toddlers and infants from the age of 4 weeks.
What is Isentress and what is it used for?
How is Isentress used?
Isentress can only be obtained with a prescription and treatment should be started by a doctor who has experience in the management of HIV infection.
The medicine is available as tablets to be swallowed (400 and 600 mg), chewable tablets (25 and 100 mg) and sachets containing granules for an oral suspension (each sachet containing 100mg). The granules are to make a mixture for children from 4 weeks of age to drink, the chewable tablets are for bigger children, and the 400- and 600-mg tablets are for different dose regimens in older children and adults, as recommended by the doctor. Equivalent doses of these different forms do not all produce the same levels of raltegravir in the body, so they must not be used interchangeably. Information on the doses and formulations to give to different patients can be found in the summary of product characteristics (also part of the EPAR).
How is Isentress used?
Treatment with Isentress should be started by a doctor who has experience in the management of HIV infection.
The oral granules are used to make oral suspensions for children aged 4 weeks and older weighing at least 3 kg. The chewable tablets are for bigger children weighing at least 11 kg, while the 400-mg tablets are for adults and children from six years of age weighing more than 25 kg.
Equivalent doses of these different forms do not produce the same levels of raltegravir in the body, so they must not be used interchangeably. Information on the doses and formulations to give to different patients can be found in the summary of product characteristics (also part of the EPAR).
How does Isentress work?
The active substance in Isentress, raltegravir, is an integrase inhibitor. It blocks an enzyme called integrase, which is involved in a step in the reproduction of HIV. When the enzyme is blocked, the virus cannot reproduce normally, slowing down the spread of infection. Isentress, taken in combination with other anti-HIV medicines, reduces the amount of HIV in the blood and keeps it at a low level. Isentress does not cure HIV infection or AIDS, but it may hold off the damage to the immune system and the development of infections and diseases associated with AIDS.
What benefits of Isentress have been shown in studies?
Isentress has been studied in six main studies:
- two studies involved a total of 699 ‘treatment-experienced’ patients who were already receiving treatment for HIV infection that was not working. The studies compared Isentress with placebo (a dummy treatment), which were added to ‘optimised background therapy’ (a combination of other anti-HIV medicines chosen for each patient as it had the best chances of reducing the levels of HIV in the blood). The main measure of effectiveness was the reduction in the levels of HIV in the blood (viral load) after 16 weeks; 77% of the patients who took Isentress had viral loads below 400 copies/ml after 16 weeks, compared with 42% of those who took placebo. The response was sustained for at least 48 weeks;
- a third study involved 566 patients who had not taken HIV treatment before and compared Isentress with efavirenz (another anti-HIV medicine). All of the patients also took tenofovir and emtricitabine (other anti-HIV medicines). The main measure of effectiveness was the number of patients who had ‘undetectable’ viral loads (below 50 copies per millilitre of blood) after 48 weeks. Isentress was as effective as efavirenz. After 48 weeks, 86% of the patients taking Isentress had viral loads below 50 copies/ml (241 out of 281), compared with 82% of those taking efavirenz (230 out of 282);
- a fourth study in 802 patients who had not taken HIV treatment before showed that giving Isentress as a single dose of 1200 mg once daily was as effective as giving 400 mg twice daily. Patients also received the medicine Truvada (emtricitabine with tenofovir disoproxil). After 48 weeks, 89% (472 of 531) of those on the once daily dose and 88% (235 of 266) of those taking Isentress twice daily had viral loads less than 40 copies/ml;
- Isentress has also been studied in a fifth study involving 126 HIV-1 infected children between 2 and 18 years whose existing treatment for HIV infection was not working. The study showed that Isentress was safe in children and levels of the medicine obtained in the blood in children were similar to those obtained in adults. Therefore, the effectiveness observed in adults is also expected in children.
- A sixth study included 26 children aged 4 weeks to 2 years who were given Isentress oral granules made into a suspension. This study looked at viral load after 24 and 48 weeks. Isentress treatment led to a reduction in viral load and after 48 weeks 53% of the children had viral loads below 50 copies/ml.
What are the risks associated with Isentress?
The most common side effects with Isentress (seen in between 1 and 10 patients in 100) are abnormal dreams, nightmares, insomnia (difficulty sleeping), depression, abnormal behaviour, dizziness, headache, psychomotor hyperactivity (restlessness), vertigo (a spinning sensation), decreased appetite, abdominal distension (swollen tummy), abdominal pain (stomach ache), diarrhoea, flatulence (gas), nausea (feeling sick), vomiting, dyspepsia (indigestion), rash, asthenia (weakness), fatigue (tiredness), pyrexia (fever), atypical lymphocytes (abnormal white blood cells), and increased blood levels of some enzymes (alanine aminotransferase, aspartate aminotransferase, lipase and pancreatic amylase) and triglycerides (a type of fat). Side effects in children were comparable to those in adults. For the full list of all side effects and restrictions with Isentress, see the package leaflet.
Why is Isentress approved?
The CHMP decided that Isentress’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 Isentress?
Recommendations and precautions to be followed by healthcare professionals and patients for the safe and effective use of Isentress have been included in the summary of product characteristics and the package leaflet.
Other information about Isentress:
The European Commission granted a conditional marketing authorisation valid throughout the European Union for Isentress on 20 December 2007. This was switched to a full marketing authorisation on 14 July 2009.
For more information about treatment with Isentress, 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.