June 30, 2010
Due to shared routes of infection -- including re-use of equipment for substance use and tattooing, as well as unprotected sex -- co-infection with hepatitis B virus and hepatitis C virus is relatively common among some HIV-positive people. Hepatitis-causing viruses infect and damage the liver and increase the risk of liver cancer in the medium- and long-term.
The liver plays a vital role for the body, filtering and metabolizing foreign substances. Many drugs are broken down by the liver, and when this organ is damaged by hepatitis-causing viruses, its ability to break down drugs is weakened. This leads to the buildup of drugs in the blood, which can lead to side effects. In some cases of co-infection, depending on the health of the liver, reduced doses of anti-HIV and other drugs may become necessary.
Researchers at the University of Bonn, Germany, have been analyzing data from three clinical trials in which raltegravir was tested in a relatively small proportion of co-infected people. They found that higher-than-normal levels of liver enzymes in the blood were more common in co-infected people than in people with HIV infection alone. Raltegravir was effective and "well tolerated" by most people, according to the research team.
This German analysis reviewed data from the following trials:
The average profile of participants at the time they entered Startmrk was as follows:
The average profile of participants at the time they entered the Benchmrk trials was as follows:
In the Benchmrk trials, participants had never previously used anti-HIV drugs and they were randomly assigned to receive one of the following regimens:
In Startmrk, participants were treatment experienced and randomly assigned to receive one of the following regimens:
Co-infected people achieved a rate of virologic success similar to that seen in people infected with HIV only. Increases in CD4+ cell counts were also similar whether or not people were co-infected.
Drug-related side effects occurred in similar proportions of people regardless of co-infection. However, serious drug-related side effects occurred more frequently in co-infected people (5.2%) than in mono-infected people (2.3%).
A large proportion (around 6%) of co-infected people taking raltegravir developed severely elevated levels of liver enzymes in their blood -- more than 10 times the upper limit of normal. This problem occurred in less than 1% of mono-infected people.
However, it is noteworthy that such high elevations of liver enzymes also occurred in co-infected people who received efavirenz or placebo.
In Startmrk, none of the co-infected people developed any of the following complications:
However, one or more of these problems occurred in about 1% of people who took raltegravir or efavirenz and who were not co-infected. A similar trend was seen in the Benchmrk trials when comparing raltegravir and placebo.
Bear in mind that the proportion of co-infected people in this study was relatively small. Co-infected people who have moderate-to-severe degrees of liver damage may need careful laboratory and clinical monitoring while being treated for HIV infection. Such people are not typical of the population initially recruited into HIV clinical trials.
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