Зидовудин химические свойства, назначение, производство
Описание
Zidovudine, also known as azidothymidine (AZT), is an antiviral agent acting via reverse
transcnptase inhibition. It was first launched in the U.K. and subsequently introduced in
over a dozen countries for the management of severe manifestations of HIV infection. In
patients with AIDS and ARC, zidovudine reduces the risk of opportunistic infections and
prolongs survival time. In symptom-free patients it shows promise in halting further
immunological deterioration.
Химические свойства
Off White Crystalline Powder
Использование
Zidovudine is an antiretroviral drug that is clinically active against HIV-1 and is intended
to treat HIV-infected patients. Zidovudine is an analog of thymidine that inhibits replication of the AIDS virus. It also turned into mono-, di-, and triphosphates by the same cellular enzymes that catalyze phosphorylation of thymidine and thymidine nucleosides.
Zidovudine-triphosphate is then included in the terminal fragment of the growing chain of
viral DNA by viral reverse transcriptase, thus causing the viral DNA chain to break apart
in cells infected with the virus.
Zidovudine has been authorized for treating patients with AIDS. It significantly prolongs the life of the patient, although it has a number of toxic effects. Synonyms of this
drug are azidothymidine and retrovir.
Показания
Zidovudine was the first agent to be used to prevent the
transmission of HIV from a pregnant woman to her
child. It was given to the mother at 14 to 34 weeks’ gestation
and to the child for the first 6 weeks of life.
Current combination therapies employ zidovudine with
another NRTI and a protease inhibitor.
Определение
ChEBI: A pyrimidine 2',3'-dideoxyribonucleoside compound having a 3'-azido substituent and thymine as the nucleobase.
Антимикробная активность
Zidovudine is active against HIV-1, HIV-2 and HTLV-1.
Приобретенная устойчивость
As with stavudine, mutations at position 41, 67 and 70, and
positions 210, 215 and 219 (the ‘thymidine analog mutations’)
of the reverse transcriptase genes are associated with
diminished antiretroviral efficacy.
Общее описание
Zidovudine, 3'-azido-3'-deoxythymidine or AZT, is ananalog of thymidine that possesses antiviral activityagainst HIV-1, HIV-2, HTLV-1, and several other retroviruses.This nucleoside was synthesized in 1978 by Linand Prusoff as an intermediate in the preparation ofamino acid analogs of thymidine. A screening program directedtoward the identification of agents potentially effectivefor the treatment of patients with AIDS led to the discoveryof its unique antiviral properties 7 years later.
Zidovudine is recommended for the management of adultpatients with symptomatic HIV infection (AIDS or ARC)who have a history of confirmed Pneumocystis carinii pneumoniaor an absolute CD4+(T4 or TH cell) lymphocytecount below 200/mm3 before therapy. The hematologicaltoxicity of the drug precludes its use in asymptomatic patients.Anemia and granulocytopenia are the most commontoxic effects associated with AZT.
Реакции воздуха и воды
Dust may form an explosive mixture in air. Water soluble. Hydrolysis occurs in strongly basic solutions .
Профиль реактивности
Zidovudine is a azido compound. Azo, diazo, azido compounds can detonate. This applies in particular to organic azides that have been sensitized by the addition of metal salts or strong acids. Toxic gases are formed by mixing materials of this class with acids, aldehydes, amides, carbamates, cyanides, inorganic fluorides, halogenated organics, isocyanates, ketones, metals, nitrides, peroxides, phenols, epoxides, acyl halides, and strong oxidizing or reducing agents. Flammable gases are formed by mixing materials in this group with alkali metals. Explosive combination can occur with strong oxidizing agents, metal salts, peroxides, and sulfides.
Пожароопасность
Flash point data for Zidovudine are not available; however, Zidovudine is probably combustible.
Фармацевтические приложения
An analog of thymidine formulated for oral or intravenous use.
Механизм действия
Zidovudine (AZT , ZDV) is an analogue of thymidine in which the azido group is substituted at the 3-carbon atom of the dideoxyribose moiety. It is active against RNA tumor viruses (retroviruses) that are the causative agents of AIDS and T-cell leukemia. Retroviruses, by virtue of RT, direct the synthesis of a provirus (DNA copy of a viral RNA genome). Proviral DNA integrates into the normal cell DNA, leading to the HIV infection. Zidovudine is converted to 5′-mono-, di-, and triphosphates by the cellular thymidine kinase. These phosphates are then incorporated into proviral DNA, because RT uses ZDV-triphosphate as a substrate. This process prevents normal 5′,3′-phosphodiester bonding, resulting in termination of DNA chain elongation because of the presence of an azido group in ZDV. The multiplication of HIV is halted by selective inhibition of RT and, thus, viral DNA polymerase by ZDV-triphosphate at the required dose concentration. Zidovudine is a potent inhibitor of HIV-1, but it also inhibits HIV-2 and EBV.
Фармакокине?тика
Oral absorption: 65%
Cmax 300 mg twice daily: 2.3 mg/L
Plasma half-life: 1.1 h
Volume of distribution: 1.6 L/kg
Plasma protein binding; 34–38%
Absorption and distribution
It is absorbed rapidly and almost completely following oral administration. Absorption is not significantly affected by food. It appears to undergo widespread body distribution. CNS penetration is fairly good. The semen:plasma ratio varies from 0.95 to 13.5 (mean 5.9). It is secreted into breast milk.
Metabolism and excretion
Following hepatic metabolism (glucuronidation), elimination is primarily renal. After oral administration, urinary recovery of zidovudine and its glucuronide metabolite accounted for 14% and 74% respectively of the dose, with a total urinary recovery of 90%.
In severe renal impairment, clearance was about half that reported in subjects with normal renal function Accumulation may occur in patients with hepatic impairment due to decreased glucuronidation.
Клиническое использование
Treatment of HIV infection in adults and children (in combination with
other antiretroviral drugs)
Reduction of maternal transmission of HIV to the fetus
Побочные эффекты
In common with other drugs in this class, use has been associated
with episodes of fatal and non-fatal lactic acidosis
and hepatomegaly with steatosis. Careful clinical evaluation
is needed in patients with evidence of hepatic abnormality.
Myelosuppression may occur within the first 4–6 weeks of
therapy. Hematological parameters should be monitored during
this period, with prompt dose modification or switch if
abnormalities are observed. Treatment with reduced doses
may be attempted in some patients once bone marrow recovery
has been observed. Myopathy is rarely seen with the use
of the current dosing regimens.
Co-administration with drugs known to cause nephrotoxicity,
cytotoxicity or which interfere with red or white blood
cell number and function may increase the risk of toxicity.
Probenecid and trimethoprim may reduce renal clearance
of zidovudine, and other drugs that are metabolized by
glucuronidation may interfere with its metabolism.
Профиль безопасности
Moderately toxic by intravenousroute. Human systemic effects by ingestion: aplasticanemia, changes in blood cell count, convulsions or effect on seizure threshold, headache, nails, retinal changes.Human mutation data reported.
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