3.4. AIDS and Opportunistic Infections: MAC: A Bacterial OI
Description
This article is from the AIDS FAQ, by Dan Greening with numerous contributions by others.
3.4. AIDS and Opportunistic Infections: MAC: A Bacterial OI
Infection with MAC is diagnosed in up to 40 percent of people with
AIDS in the United States, making it the most common bacterial
OI. Usually, it affects people in advanced stages of HIV disease when
the immune system is severely suppressed.
The MAC organism is found widely in the environment and is thought to
be acquired most commonly through the mouth or gastrointestinal
tract. It can spread to the lungs, liver, spleen, lymph nodes, bone
marrow, intestines and blood. MAC causes chronic debilitating
symptoms--fever, night sweats, weight loss, fatigue, chronic diarrhea,
abdominal pain, liver dysfunction and severe anemia.
Rifabutin is the first drug to be approved for preventing MAC disease
in people with advanced HIV infection. The Food and Drug
administration based this approval on clinical studies showing that
patients who received rifabutin were one-third to one-half as likely
to develop MAC as were patients who received placebo.
To prevent MAC disease, a U.S. Public Health Service Task Force on
Prophylaxis and Therapy for MAC suggests that patients with HIV
infection and fewer than 100 CD4 + T cells receive oral rifabutin for
the rest of their lives unless disease develops. In the latter case,
multiple drug treatment is needed. CD4+ T cells are immune system
cells targeted and killed by HIV. No other drug regimen is recommended
currently to prevent MAC. Azithromycin and clarithromycin are
promising agents for prophylaxis, but studies of these agents have not
been completed.
Increasing evidence suggests that treatment can benefit patients with
disseminated MAC, especially multiple-drug regimens including either
clarithromycin or azithromycin. Therefore, the PHS task force suggests
that all regimens, outside of a clinical trial, should consist of at
least two drugs, including clarithromycin or azithromycin plus one
other agent such as clofazimine, rifabutin, rifampin, ciprofloxacin
and, in certain situations, amikacin. They recommend continued therapy
for the patient's lifetime, as long as clinical benefit and reduction
of mycobacteria are observed.
NIAID has several studies under way looking at the roles of
clarithromycin and azithromycin, and other drugs such as sparfloxacin,
alone and in combination, to prevent and treat this serious disease.
Continue to:
My Books
