Molecular structure of AZT
Find information on thousands of medical conditions and prescription drugs.

Zidovudine

Zidovudine (INN) or azidothymidine (AZT) is an antiretroviral drug, the first one approved for treatment of HIV. It is also sold under the names Retrovir® and Retrovis®, and as an ingredient in Combivir® and Trizivir®. It is an analog of thymidine. more...

Home
Diseases
Medicines
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
Zafirlukast
Zagam
Zalcitabine
Zaleplon
Zanaflex
Zanamivir
Zantac
Zarontin
Zelnorm
Zerit
Zestoretic
Zestril
Zetia
Zevalin
Ziagen
Zidovudine
Zileuton
Ziprasidone
Zithromax
Zocor
Zofran
Zoladex
Zoledronic acid
Zolmitriptan
Zoloft
Zolpidem
Zometa
Zomig
Zonegran
Zonisamide
Zopiclone
Zosyn
Zovia
Zovirax
Zyban
Zymar
Zyprexa
Zyrtec
Zyvox

History

Zidovudine was the first drug approved for the treatment of AIDS and HIV infection. Jerome Horowitz first synthesized AZT in 1964, under a US National Institutes of Health (NIH) grant. It was originally intended to treat cancer, but failed to show efficacy and had an unacceptably high side effect profile. The drug then faded from view until February 1985, when Samuel Broder, Hiroaki Mitsuya, and Robert Yarchoan, three scientists in the National Cancer Institute (NCI), collaborating with scientists in Burroughs Wellcome Co., started working on it as an AIDS drug. After showing that this drug worked against HIV in the test tube, the team conducted the initial clinical trial that provided evidence that it could increase CD4 counts in AIDS patients. Like other reverse transcriptase inhibitors, AZT inhibits HIV replication by blocking the action of reverse transcriptase, the enzyme that HIV uses to replicate its RNA for splicing into the DNA of a target cell.

A placebo-controlled randomized trial of AZT was subsequently conducted by Burroughs-Wellcome (now GlaxoSmithKline), in which it was shown that it could prolong the life of patients with AIDS. Burroughs Wellcome Co. filed for a patent on AZT in 1986. The Food and Drug Administration (FDA) approved the drug (via the then-new FDA accelerated approval system) for use against HIV, AIDS, and AIDS Related Complex (ARC, a now-defunct medical term for pre-AIDS illness) on March 20, 1987, and then as a preventive treatment in 1990. It was initially administered in much higher dosages than today, typically one 400mg dose every four hours (even at night). However, the unavailability at that time of alternatives to treat AIDS affected the risk/benefit ratio, with the certain toxicity of HIV infection outweighing the risk of drug toxicity. One of AZT's side-effects includes anemia, a common complaint in early trials.

Modern treatment regimens typically use lower dosages two to three times a day in order to improve the overall quality of life. Like other antiretroviral drugs, AZT is also almost always used in highly active antiretroviral therapy (HAART). That is, it is combined with other drugs in order to prevent mutation of the HIV into an AZT-resistant form.

The crystal structure of AZT was reported by Alan Howie (Aberdeen University) in 1988. In the solid state AZT forms a hydrogen bond network. Note that AZT is based upon a sugar.

Treatment

When used as a preventative treatment, AZT has proven to be particularly effective. If treatment is started before the total amount of virus, known as the viral load, reaches a critical point of 50 million parts per millilitre of blood serum, the chance of AIDS developing is effectively zero. This is widely used with medical practitioners who receive accidental infections (please see discussion).

Read more at Wikipedia.org


[List your site here Free!]


Zidovudine in First Trimester Not Linked to Higher Risk of Birth Defects - Brief Article - Statistical Data Included
From Family Pratice News, 3/15/00 by Barbara Baker

SAN FRANCISCO -- Zidovudine monotherapy during the first trimester of pregnancy does not appear to increase the risk of birth defects detected at the time of delivery.

The finding comes from the largest U.S. prospective registry of the potential teratogenic effects of antiretroviral therapy detected at the time of birth, Dr. Patricia M. Garcia reported at the Seventh Conference on Retroviruses and Opportunistic Infections.

The registry does not yet contain enough accumulated pregnancy exposures to other antiretroviral agents used alone or in combination to reach any reliable conclusion regarding their teratogenic risk, said Dr. Garcia of Northwestern University in Chicago.

She reported on birth defects seen among 916 pregnancies in HIV-positive women prospectively enrolled in the Antiretroviral Pregnancy Registry during the last 10 years. The mean maternal age was 27 years.

So far, 343 live-born infants were exposed to any antiretroviral agent during the first trimester. The prevalence of birth defects detected at delivery in this group was 2.0 per 100 live births.

This rate is similar to that observed among infants exposed to any antiretroviral drug during the second and/or third trimester. Their incidence of birth defects was 2.7 per 100 live births.

The observed rate of birth defects is also similar to the expected rate in the general population, 2.2 per 100 live births, Dr. Garcia said at the meeting sponsored by the Foundation for Retrovirology and Human Health.

The greatest number of first-trimester exposures were to zidovudine monotherapy Among 111 live births in this group, there was one birth defect, for an incidence of 0.9 per 100 live births.

Of potential concern was that there were two cases of birth defects detected among 10 infants who were exposed to the combination of nucleoside reverse transcriptase inhibitors, nonnucleoside reverse transcriptase inhibitors, and protease inhibitors during the first trimester.

One of these infants had transposed organs and the other had renal pelviectasis.

These defects do not appear to have a related etiology, and there are too few reported exposures to accurately estimate whether the combination therapy carries a terarogenic risk, Dr. Garcia said. The observation warrants continued surveillance, she. added.

Prospective reports of antiretroviral exposures during pregnancy can be made to the Antiretroviral Pregnancy Registry by calling 800-258-4263.

COPYRIGHT 2000 International Medical News Group
COPYRIGHT 2001 Gale Group

Return to Zidovudine
Home Contact Resources Exchange Links ebay