Basic
Informations
Viread is an HIV medication.
It is in a category of HIV medicines called nucleotide reverse
transcriptase inhibitors (NRTI). Viread prevents HIV from altering
the genetic material of healthy CD4 cells. This prevents the cells
from producing new virus and decreases the amount of virus in the
body.
Nucleotide analogues, such as Viread, are very similar to nucleoside
analogues [e.g., Retrovir (AZT), Ziagen (abacavir) and Emtriva (emtricitabine)].
The only difference is that nucleotide analogues, unlike nucleoside
analogues, are chemically preactivated and thus require less
processing in the body for them to become active.
Viread, manufactured by Gilead Sciences, was approved by the U.S.
Food and Drug Administration for the treatment of HIV in 2001.
Viread is available in pharmacies as a single drug, which is always
combined with other HIV drugs, or in the fixed-dose combination
tablets Truvada (Viread and Emtriva) and Atripla (Viread, Emtriva,
and Sustiva [efavirenz]).
Viread is also active against the hepatitis B virus (HBV), the virus
responsible for hepatitis B. Although it has not been approved by
the FDA for the treatment of hepatitis B, some doctors prescribe it
to treat both hepatitis B and HIV.
Drugs
Interactions
Viread should not be taken at
the same time as Atripla, Truvada, or Hepsera. This is because these
medications contain the same or similar active ingredients as
Viread.
HIV-positive people must be very careful about using Viread in
combination with Videx/Videx EC (ddI). There are two important
warnings to know about:
-
Drug regimens consisting
of Sustiva (efavirenz) or Viramune (nevirapine) plus Viread and
Videx EC have been associated with premature drug failure. If
you are receiving Viread and Videx EC with either Sustiva or
Viramune, you may want to discuss alternative options with your
doctor.
-
Viread increases the
amount of Videx EC in the body. This can increase the risk of
Videx-related side effects. In turn, if Viread and Videx EC are
used together, you may need to be followed more carefully and
your health care provider may need to decrease your dose of
Videx EC. If used with Viread, Videx EC should be taken at a
dose of 250mg once a day (reduced from the usual daily dose of
400mg a day).
-
Because there are now a
number of concerns regarding the use of Viread in combination
with Videx EC, many experts recommend avoiding this combination.
The protease inhibitors
Reyataz (atazanavir), Prezista and Kaletra (lopinavir/ritonavir) can
increase the amount of Viread in the blood, which could result in
more side effects. You may need to be followed more carefully if you
are taking Viread and Reyataz, Prezista or Kaletra together. Viread
may decrease the amount of Reyataz in your blood. If you are taking
Viread and Reyataz together you should also be taking Norvir.
Side
Effects
Lactic acidosis, which can be
fatal, and severe liver problems have been reported in people taking
nucleoside reverse transcriptase inhibitors (NRTIs). This may be
more likely to occur in pregnant women. 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 area.
Viread may cause bone problems. In one clinical trial conducted by
the manufacturer involving HIV-positive patients who were new to HIV
therapy, Viread [combined with Sustiva and Epivir] caused decreases
bone in mineral density (osteopenia) at the hip and spine.
Researchers are currently looking into the seriousness of this
possible side effect. If you have a history of bone fracture or are
at risk for osteopenia, your doctor may want to consider ordering
bone scans on a regular basis while you are taking Viread. While
it's not clear if calcium and vitamin D supplementation can help
with this side effect, it might be beneficial if you are taking
Viread.
Some patients treated with Viread have had kidney problems. It is
recommended that your doctor order a simple laboratory test to
calculate your "creatinine clearance," which is a measure of your
kidney function, before you start taking Viread. Depending on the
results of this test, you may not be able to take Viread, or you may
need to take it less frequently. Viread can be problematic for
HIV-positive people who have a history of kidney problems (renal
impairment). If you have a history of kidney problems, your doctor
should monitor your kidney function closely through regular blood
tests. It is always important to be careful if using Viread in
combination with drugs that cause kidney problems or other drugs
that are removed from the body by the kidneys.
HIV drug regimens containing NRTIs, including Viread, can cause
increased fat levels (cholesterol and triglycerides) in the blood,
and 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). These side effects of
HIV drug therapy are reviewed in our lessons on Lipodystrophy,
Facial Lipoatrophy, and Risks To Your Heart (Hyperlipidemia).
In people living with HIV, the most common side effects of Viread
are rash, headache, pain, diarrhea, depression, weakness, and
nausea. Less common side effects include vomiting, dizziness and
flatulence.
If you have hepatitis B and HIV and plan to stop taking Viread, you
need close medical follow-up and for several months your doctor
might want to frequently check your liver enzymes after stopping
treatment. This is because Viread is also active against the
hepatitis B virus (HBV). If Viread is stopped abruptly, it can cause
liver disease to "flare" and damage the liver.
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