Crixivan - indinavir
What is Crixivan?
Crixivan is a medicine that contains the active substance indinavir. It is available in the form of white capsules (100, 200, 333 and 400 mg).
What is Crixivan used for?
Crixivan is an antiviral drug. It is used in combination with other antiviral medicines to treat adults, adolescents and children of four years of age or older infected with human immunodeficiency virus type 1 (HIV-1), a virus that causes acquired immunodeficiency syndrome. (AIDS) For adolescents and children, the benefits of Crixivan therapy should be carefully weighed in consideration of the increased risk of nephrolithiasis (kidney stones).
The medicine can only be obtained with a prescription.
How is Crixivan used?
Crixivan should be administered by physicians experienced in the treatment of HIV infection. Crixivan should be used in combination with other antiviral medicines. The standard dose for adults is 800 mg every eight hours. For children, the dose depends on the surface area. body (calculated based on the weight and height of the child). The capsules should be swallowed whole on an empty stomach, with water, one hour before or two hours after a meal. Alternatively, Crixivan can be given with a light, low-fat meal.
In adults, Crixivan can be taken at a dose of 400 mg twice daily if each dose is taken with 100 mg of ritonavir (another antiviral medicine) with or without meals, in combination with other antiviral medicines. The use of Crixivan with ritonavir is based on limited evidence. The dose of Crixivan should be adjusted in patients taking other medicines or who have liver (liver) problems. To avoid the risk of developing kidney stones, patients should drink a lot (at least 1.5 liters of fluids per day in the case of adults).
How does Crixivan work?
The active substance in Crixivan, indinavir, is a protease inhibitor. That is, it blocks an enzyme called protease which is involved in the reproduction of HIV. If the enzyme is blocked, the virus is unable to reproduce normally and the infection is slowed down. Taken in combination with other antiviral medicines, Crixivan reduces the amount of HIV in the blood and keeps it at a low level.
Crixivan does not cure HIV infection or AIDS, but it can delay damage to the immune system and the development of AIDS-associated infections and diseases.
Ritonavir is another protease inhibitor used as a "booster". It slows down the metabolism rate of indinavir by increasing the levels of indinavir in the blood. This allows a lower dose of indinavir to be used for the same antiviral effect.
How has Crixivan been studied?
The efficacy of Crixivan taken without ritonavir was studied in three studies involving 524 HIV-infected patients. The first study compared the effects of Crixivan with those of zidovudine (another antiviral medicine) and with a combination of both medicines. The other two studies compared Crixivan taken together with zidovudine and didanosine or lamivudine (other antiviral medicines) with Crixivan alone and in combination with zidovudine and didanosine or lamivudine. Crixivan, taken in combination with stavudine and lamivudine (other antiviral medicines), has also been studied in 41 children aged between four and 15 years. The main measure of effectiveness was the level of HIV in the patients' blood (viral load) at 24 weeks after treatment.
The company also presented the results of four studies from the scientific literature looking at the effects of taking Crixivan in combination with ritonavir. One study involved 20 patients already taking Crixivan without ritonavir and three other studies involved 123 patients who had never been treated before for HIV infection.
What benefit has Crixivan shown during the studies?
Crixivan, taken in combination with other antiviral medicines but not ritonavir, was more effective than the comparator medicines in reducing viral load. In the first study, more patients who had taken Crixivan with zidovudine had a 99% reduction in viral load at 24 weeks, compared to those who had taken Crixivan alone. In the second study, 53% of the patients who took Crixivan with two other antiviral medicines had a reduction in viral load of at least 99% compared to 20% of those who took Crixivan alone or zidovudine and didanosine. The third study gave similar results: 90% of those who took three medicines, including Crixivan, had a viral load of less than 500 copies / ml, compared with 43% of those who took Crixivan alone and 0% of those who took Crixivan alone. those who had taken two antiviral medicines. About half of the children included in the studies had a viral load below 50 copies / ml after 24 weeks of taking Crixivan with two other antiviral medicines.
Studies of Crixivan taken with ritonavir revealed that the combination produced blood levels of indinavir similar to those of Crixivan taken without ritonavir. The combination has been shown to be effective for up to two years.
What is the risk associated with Crixivan?
The most common side effects with Crixivan (seen in more than 1 in 10 patients) are headache, dizziness, nausea, vomiting, diarrhea, dyspepsia (heartburn), rash, dry skin, asthenia (weakness), fatigue, change in taste (an unusual taste in the mouth) and abdominal pain. Nephrolithiasis has been found to be very common in children from the age of three. For the full list of side effects reported with Crixivan, see the Package Leaflet.
Crixivan should not be used in people who may be hypersensitive (allergic) to indinavir or any of the other ingredients (components). Crixivan should not be used in patients undergoing treatment with any of the following medicines:
- medicines which are metabolised similarly to Crixivan and which are harmful at high levels in the blood;
- amiodarone (to correct an irregular heartbeat);
- terfenadine, astemizole (commonly used to treat allergy symptoms - these medicines are available without a prescription);
- cisapride (to treat certain stomach problems);
- alprazolam, triazolam, midazolam taken by mouth (to treat anxiety or sleep difficulties);
- pimozide (to treat mental illness);
- ergotine derivatives (to treat migraines)
- simvastatin, lovastatin (to lower blood cholesterol)
- rifampicin (for the treatment of tuberculosis);
- St. John's wort (herbal medicine used to treat depression).
Care should be taken if Crixivan is taken at the same time as other medicines. For more information, see the package leaflet.
Additional restrictions should be observed when Crixivan is taken with ritonavir. See the full listing of ritonavir in the package leaflet.
As with other HIV medicines, patients receiving Crixivan may also be at risk for lipodystrophy (changes in the distribution of body fat), osteonecrosis (death of bone tissue) or immune reactivation syndrome (symptoms of infections caused by reactivation of the system). immune). Patients with liver problems (including hepatitis B or C infection) may be at an increased risk of developing liver damage when treated with Crixivan.
Why has Crixivan been approved?
The Committee for Medicinal Products for Human Use (CHMP) decided that the benefits of Crixivan in combination with antiretroviral nucleoside analogues are greater than its risks in the treatment of HIV-infected adults, adolescents and children over four years of age. 1. The Committee recommended that Crixivan be given marketing authorization.
Crixivan was originally authorized "in exceptional circumstances" because, for scientific reasons, the data available at the time of approval was limited. As the company provided the additional information requested, the "exceptional circumstances" condition was removed. "April 8, 1998.
Other information about Crixivan:
The European Commission granted Merck Sharp & Dohme Limited a "marketing authorization" valid throughout the European Union for Crixivan on 4 October 1996. This authorization was renewed on 4 October 2001 and 4 October 2006.
For the full version of Crixivan's EPAR click here.
Last update of this summary: 06-2008.
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