Resistance to zidovudine develops due to-: (A) Mutations at reverse transcriptase, (B) Increased efflux of the drug from inside the cell, (C) Increased metabolism of the drug, (D) Decreased zidovudine 5 triphosphate formation
Answer is A. Ans. is 'a' i.e., Mutations at reverse transcriptase "Resistance to Zidovudine occurs by point mutation which alters reverse transcriptase enzyme. In the past when AZT was used alone, > 50% patients became nonresponsive to AZT within 1-2 years therapy due to growth of resistant mutants" - KDT