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Check out our Clinical Trials page to see studies that a currently enrolling HIV-positive people.
The treatment of HIV/AIDS has evolved in the last 20
years since the beginning of the epidemic from no treatment
to treatment with a single drug (AZT) to dual-drug therapy
and, now, to highly active antiretroviral therapy (HAART).
HAART is defined as treatment with at least three active
anti-retroviral medications (ARV’s), typically
two nucleoside or nucleotide reverse transcriptase inhibitors
(NRTI’s) plus a non-nucleoside reverse transcriptase
inhibitor (NNRTI) or a protease inhibitor (PI) or another
NRTI called abacavir (Ziagen).
HAART is often called
the drug “cocktail” or triple-therapy. HAART
affords us a potent way of suppressing viral replication
in the blood while attempting to prevent the virus from
rapidly developing resistance to the individual ARV’s.
Suppressing viral replication with HAART allows the
body time to rebuild its immune system and replenish
the destroyed CD4 or T cells. HAART has been clearly
shown to delay progression to AIDS and prolong life.
Note that a curative treatment of HIV/AIDS is not possible
at the present time, or in the near future, and when
HAART is stopped, HIV becomes detectable in the blood
once again.
At the present time, we have seven NRTI’s, three NNRTI’s and six PI’s to choose from that have been approved by the Food and Drug Administration (FDA). What combination of drugs to start in a person who is “naive” to therapy (has never been on HAART) depends on the viral load and the patient’s life circumstances, as the various ARV’s frequently have to be taken at different times of the day and with or without food. This decision is best made in conjunction with a health care provider (HCP) who knows the person well and who is well-versed in the treatment of people with HIV/AIDS. Other medications may also need to be taken depending on what the person’s CD4 cell count is. For example, people who have CD4 counts below 200 are susceptible to Pneumocystis carinii pneumonia (PCP), and taking trimethoprim-sulfamethoxazole (Bactrim) prophylactically significantly reduces the chances of developing this infection.
Failure of HAART
“Failure” of therapy can occur, defined
as having a detectable viral load in the blood. Sometimes,
the viral load rises only transiently and at low levels,
called “blips”. This can occur if the viral
load was measured while the person was ill or recently
got a vaccine. Blips are not a reason to switch therapy,
as the viral load will frequently become undetectable
if measured a gain after a few weeks. Failure of HAART
is a sustained and high rise in the viral load. People
fail their HAART regimens for various reasons: non-adherence
to the regimen, side effects from the medications, and
development of resistance of HIV to the various medications
in the regimen. When this happens, the regimen has to
be switched. The HCP will frequently order a genotype
or phenotype test (as explained elsewhere), and use
the information provided by these tests to devise the
best next regimen. The new regimen is called a “salvage”
regimen.
New strategies
The field of HIV/AIDS is rapidly evolving. Treatment
strategies for ARV-naive and “experienced”
people are evolving as well. What defines optimal naive
and salvage regimens is debatable and is the subject
of many clinical trials. For example, should a naive
regimen contain an NNRTI or a PI? Does directly observed
therapy improve adherence to HAART? Does treatment with
glucose- or cholesterol-lowering medications improve
the metabolic side effects (diabetes and high cholesterol)
of HAART? Does monitoring drug levels in the blood and
raising the dosages of the ARV’s increase viral
suppression and success of a HAART regimen? Does therapeutic
vaccination and structured treatment interruption work?
We at the NYU Center For AIDS Research and the NYU/Bellevue Adult AIDS Clinical Trials Unit are trying to answer some of these questions.