How Does HIV Become Resistant To AZT?

How does AZT work against HIV?

AZT interferes with an enzyme called reverse transcriptase (RT), which is used by HIV-infected cells to make new viruses.

Since AZT inhibits, or reduces the activity of this enzyme, this drug causes HIV-infected cells to produce fewer viruses..

Can you be HIV resistant?

A small proportion of humans show partial or apparently complete inborn resistance to HIV, the virus that causes AIDS. The main mechanism is a mutation of the gene encoding CCR5, which acts as a co-receptor for HIV. It is estimated that the proportion of people with some form of resistance to HIV is under 10%.

Do humans have reverse transcriptase?

They are found abundantly in the genomes of plants and animals. Telomerase is another reverse transcriptase found in many eukaryotes, including humans, which carries its own RNA template; this RNA is used as a template for DNA replication.

Do they still use AZT?

These so-called antiretroviral drugs have made it possible for people diagnosed with HIV to live long and relatively healthy lives, as long they continue to take the medications. And for most of these people, their therapy often still includes AZT.

Did AZT save lives?

Mortality rates for people taking AZT were staggeringly lower than those taking the placebo; there had been 19 deaths in the placebo group of 137 people, but only one in the AZT group of 145. Those on AZT also had a decreased number of opportunistic infections and showed improvement in weight gain and T4 cell counts.

Why does resistance to AZT develop?

The canonical AZT-resistance mutations cause AZT resistance because they enhance the ability of HIV-1 RT to bind ATP appropriately, thus enhancing the excision reaction.

Why is AZT toxic to humans?

AZT also suppresses the production of red blood cells, neutrophils, and other cells in the bone marrow, causing symptoms such as fatigue, malaise, and anemia, and many patients taking AZT experience mild gastrointestinal intolerance, which may cause nausea and vomiting.

Is AZT an NRTI?

While often listed in chronological order, NRTIs/NtRTIs are nucleoside/nucleotide analogues of cytidine, guanosine, thymidine and adenosine: Thymidine analogues: zidovudine (AZT) and stavudine (d4T)

Can viruses develop drug resistance?

When an influenza virus changes in the active site where an antiviral drug works, that virus shows reduced susceptibility to that antiviral drug. Reduced susceptibility can be a sign of potential antiviral drug resistance. Antiviral drugs may not work as well in viruses with reduced susceptibility.

What happens when you miss ARV pill for a day?

Missing doses of HIV medicines can reduce their usefulness and increase the possibility of developing drug resistance, which makes certain HIV drugs lose their effectiveness. If you realize you have missed a dose, go ahead and take the medication as soon as you can, then take the next dose at your usual scheduled time.

How does HIV become resistant to medications?

With HIV, drug resistance is caused by changes (mutations) in the virus’s genetic structure. These mutations can lead to changes in certain proteins, most commonly enzymes, which help HIV reproduce (replicate). Mutations are very common in HIV.