Resistance to zidovudne develops due to:
Zidovudine;It is a thymidine analogue (azidothymidine, AZT), the prototype NI. After phosphorylation in the host cell-zidovudine triphosphate selectively inhibits viral reverse transcriptase (RNA-dependent DNA polymerase) in preference to cellular DNA polymerase Resistance to AZT occurs by point mutations which alter reverse transcriptase enzyme. ESSENTIALS OF MEDICAL PHARMACOLOGY K.D.TRIPATHI SIXTH EDITION PAGE NO:770
Mutation at reverse transcriptase
Increased efflux of the drug from inside the cell
Increased metabolism of the drug
Decreased zidovudine 5 triphosphate formation
Chemotherapy