Interrupting HIV treatment could be beneficial
Friday, August 4, 2006, 13:00
People infected with HIV don't need continuous treatment and taking breaks can reduce spending on drugs and exposure to toxic side effects without endangering patients' health, a study published today in the Lancet found. The virus remained controlled and did not become resistant to drugs after breaks in treatment in a study of 430 patients led by Bernard Hirschel at the University of Geneva. ”The results provide reassurance about the development of resistance and loss of efficacy of treatment,” Hirschel said in the study. „Scheduled treatment interruptions lasting many months, with substantial drug savings, can be anticipated.” Cocktails of new HIV medicines have lengthened the time infected patients can survive without developing AIDS, but treatment costs between $10,000 and $15,000 a year and can cause side effects such as liver damage. Giving intermittent therapy with drugs made by companies including GlaxoSmithKline Plc and Roche Holding AG would reduce both costs and toxic effects. Doctors have been concerned that such breaks in treatment would lead to disease progression and increased drug resistance. In the study, the 430 patients with chronic HIV infection were either given a cocktail of medicines continuously for an average of 22 months or assigned a pause in treatment. To be eligible for the trial, patients had to have blood levels of CD4, an indicator of the immune system's strength, of at least 350 cells per micro-liter and at most 50 copies of the HIV virus in a milliliter of blood at the start of the study.
Patients who were assigned a break in treatment were monitored and put back on it for at least 12 weeks if two blood tests confirmed that the measure of the immune system's health had fallen below 350. They stopped the drugs again when the measure improved. Overall, patients who had a break in treatment were on medicines 37.5% of days compared with 99% of days in the continuous treatment group. They experienced less diarrhea and nausea, but suffered more from an oral and genital yeast infection. According to the study calculations of the amount of medication used by each group showed that the potential for diminishing use of antiretroviral drugs through scheduled treatment interruptions is substantial.
In another study published in today's Lancet, scientists at the University of Bristol in the U.K. looked at data from more than 22,200 HIV infected patients in Europe and North America who had started treatment for the first time between 1995 and 2003. Though control of HIV virus levels has improved over the years, the risk of death in the first year after starting treatment has remained about the same since, the researchers, led by scientist Margaret May, found. They also found evidence that the risk of the patients going on to develop AIDS has increased since 1998. The study links this to a spread in the respiratory disease tuberculosis, which also weakens the immune system. Tuberculosis is the leading cause of death in HIV-infected people, according to the WHO. (Bloomberg)