What is Ziagen
Ziagen is an anti-HIV medication. It is in a
category of HIV medications called nucleoside
reverse transcriptase inhibitors (NRTIs).
Ziagen prevents HIV from altering the genetic
material of healthy T-cells. This prevents the
cells from producing new virus and decreases
the amount of virus in the body.
Ziagen, manufactured by GlaxoSmithKline, was
approved for the treatment of HIV by the U.S.
Food and Drug Administration (FDA) in 1998.
Ziagen is available in pharmacies as a single
drug, which is always combined with at least
two other anti-HIV drugs, or in combination
What about side effects
Approximately 5 percent of people who take Ziagen
are allergic to it and can experience a "hypersensitivity
reaction." This can be serious and may
require that Ziagen therapy be stopped. A hypersensitivity
reaction usually appears during the second week
of therapy, but it can take as long as six weeks
to notice any symptoms. The most common symptoms
are fever and rash, followed by headaches, stomach
upset, feeling tired, sore throat, cough, and
shortness of breath. These symptoms usually
get worse over time and it is important that
you report them to your doctor immediately.
An inexpensive laboratory test is available
to look for an inherited gene, called HLA-B*5701,
that has been linked to the hypersensitivity
reaction in HIV-positive people taking Ziagen.
While not all people with this gene experience
an allergic reaction while taking Ziagen, most
do. In turn, if you are tested and found to
have this gene, Ziagen (or other medications
containing abacavir) should either be avoided
or used with caution. If you and your doctor
are thinking about starting Ziagen or another
abacavir-containing medication for the first
time, be sure to discuss this genetic test.
If your doctor tells you that you are allergic
or are having a hypersensitivity reaction, you
will be told to stop the drug. If you stop taking
Ziagen because of these symptoms, you must not
start the drug again, or start any drug that
contains Ziagen (e.g. Trizivir
or Epzicom). Some
people who were allergic to the drug and restarted
therapy saw their symptoms return immediately
and became very ill.
Lactic acidosis, which can be fatal, and severe
liver problems have been reported in people
taking NRTIs including Ziagen. Contact your
doctor immediately if you experience nausea,
vomiting, or unusual or unexpected stomach discomfort;
weakness and tiredness; shortness of breath;
weakness in the arms and legs; yellowing of
the skin or eyes; or pain in the upper stomach
Some of the more common side effects include
appetite loss, headaches, feeling crummy (malaise),
nausea, vomiting, and diarrhea. Very often,
these side effects improve within a few months/weeks
of starting Ziagen.
Anti-HIV drug regimens containing NRTIs, including
Ziagen, can cause increased fat levels (cholesterol
and triglycerides) in the blood, abnormal body-shape
changes (lipodystrophy; including increased
fat around the abdomen, breasts, and back of
the neck, as well as decreased fat in the face,
arms, and legs), and diabetes. These side effects
of anti-HIV drug therapy are reviewed in our
lessons on Lipodystrophy, Facial Lipoatrophy,
and Risks To Your Heart (Hyperlipidemia).
How does it work?
As with all the NRTI (nucleoside reverse transcriptase
inhibitor) drugs, Ziagen works by terminating
the growing DNA (gene) chain of HIV as it is
trying to reproduce itself. This results in
defective HIV particles that are unable to infect
When taken regularly as prescribed, Ziagen combination
therapy usually leads to a decrease in HIV viral
load (RNA) in the blood and an increase in the
CD4 cell count.
In other studies, these benefits have been associated
with decreased rates of AIDS opportunistic infections,
improved quality of life and increased survival.
What about drug interactions?
can increase the amount of the protease inhibitor
and probably Lexiva (fosamprenavir)
in the body. However, it is not necessary to
change the doses of either Ziagen or Agenerase/Lexiva.
Ziagen can increase the rate at which methadone,
a drug often used to help manage symptoms of
heroin withdrawal, is cleared from the body.
If you are taking methadone and Ziagen at the
same time, it might be necessary to increase
your methadone dose.