Question

How does AZT prevent viral replication?

Answer 1

AZT, in full azidothymidine, also called zidovudine, is a drug that is used in delaying HIV infection so that it will slow the disease called AIDS.

AZT belongs to a group of drugs known as nucleoside reverse transcriptase inhibitors .The HIV virus is an RNA virus (or retrovirus) and to enter a cell it has to use an enzyme called reverse transcriptase.
This way it can form host DNA from its' viral RNA. It then can insert itself into the host cell and take it over.

One problem, is that it can also interfere with mitochondrial DNA polymerase. Remember, that mitochondria have their own DNA.
Muscle cells have many mitochondria and the effect is muscle weakness, both skeletal and heart muscle.

On top of it all ATZ suppresses red blood cell formation. ATZ is often given in a "cocktail" with other antivirals.

ATZ does help in deducing the chance of transmission from mother to fetus.