General
Description & Use
Used alone or with other medications to treat human immunodeficiency
virus (HIV) infection in patients with or without acquired immunodeficiency
syndrome (AIDS). It will slow the spread of HIV infection in the
body. Zidovudine is not a cure and may not decrease the number
of HIV-related illnesses.
Zidovudine also known as (Zidovir-300, Azt, Retrovir, Zdvor azidothymidine
(AZT) and ZDV) is an antiretroviral drug, the first approved for
treatment of HIV. It is also sold under the names Retrovir and
Retrovis, and as an ingredient in Combivir, Epzicom and Trizivir.
It is an analog of thymidine. AZT may be used in combination with
other antiretroviral medications to substantially reduce the risk
of HIV infection following a significant exposure to the virus
(such as a needle-stick injury involving blood or body fluids
from an individual known to be infected with HIV).
See
Lamvir
HBV Epivir and Duovir
-
Also see Viramune Nevirapine
AZT
is also recommended as part of a regimen to prevent mother-to-child
transmission of HIV during pregnancy, labor and delivery.[7] With
no treatment, approximately 25% of infants whose mothers are infected
with HIV will become infected. AZT has been shown to reduce this
risk to approximately 8% when given in a three-part regimen during
pregnancy, delivery and to the infant for 6 weeks after birth.[8]
Use of appropriate combinations of antiretroviral medications
and cesarean section when necessary can further reduce mother-child
transmission of HIV to 1-2%. Like other reverse transcriptase
inhibitors,
AZT works by inhibiting the action of reverse transcriptase, the
enzyme that HIV uses to make a DNA copy of its RNA. Reverse transcription
is necessary for production of the viral double-stranded DNA,
which is subsequently spliced into the genetic material of a target
cell (where it is called a provirus). The azido group increases
the lipophilic nature of AZT, allowing it to cross cell membranes
easily by diffusion and thereby also to cross the blood-brain
barrier. Cellular enzymes convert AZT into the effective 5'-triphosphate
form.
Studies
have shown that the termination of the formed DNA chains is the
specific factor in the inhibitory effect. AZT does not destroy
the HIV infection, but only delays the progression of the disease
and the replication of virus, even at very high doses. During
prolonged AZT treatment HIV has the ability to gain an increased
resistance to AZT by mutation of the reverse transcriptase. A
study showed that AZT could not impede the resumption of virus
production, and eventually cells treated with AZT produced viruses
as much as the untreated cells. So as to slow the development
of resistance, it is generally recommended that AZT be given in
combination with another reverse transcriptase inhibitor and an
antiretroviral from another group, such as a protease inhibitor
or a non-nucleoside reverse transcriptase inhibitor.
Common side effects of AZT include nausea, headache, changes in
body fat, and discoloration of fingernails and toenails. More
severe side effects include anemia and bone marrow suppression,
which can be overcome using erythropoietin or darbepoetin treatments.
These unwanted side effects might be caused by the sensitivity
of the DNA polymerase in the cell mitochondria. AZT has been shown
to work additively or synergistically with many anti-HIV agents;
however, acyclovir and ribavirin decrease the antiviral effect
of AZT.
Drugs
that inhibit hepatic glucuronidation, such as indomethacin, acetylsalicylic
acid (Aspirin) and trimethoprim, decrease the elimination rate
and increase the toxicity. RETROVIR is the brand name for zidovudine
(formerly called azidothymidine [AZT]), a pyrimidine nucleoside
analogue active against HIV.
Tablets: RETROVIR Tablets are for oral administration. Each film-coated
tablet contains 300 mg of zidovudine and the inactive ingredients
hypromellose, magnesium stearate, microcrystalline cellulose,
polyethylene glycol, sodium starch glycolate, and titanium dioxide.
Capsules:
RETROVIR Capsules are for oral administration. Each capsule contains
100 mg of zidovudine and the inactive ingredients corn starch,
magnesium stearate, microcrystalline cellulose, and sodium starch
glycolate. The 100-mg empty hard gelatin capsule, printed with
edible black ink, consists of black iron oxide, dimethylpolysiloxane,
gelatin, pharmaceutical shellac, soya lecithin, and titanium dioxide.
The blue band around the capsule consists of gelatin and FD&C
Blue No. 2.
