Antiviral activity and resistance profile of phosphazid--a novel prodrug of AZT

Nucleosides Nucleotides. 1999 Apr-May;18(4-5):901-6. doi: 10.1080/15257779908041597.


Both AZT and its novel 5'-hydrogen phosphonate derivative, Phosphazid, possess similar in vitro activity and resistance profiles. Experiments involving AZT-resistant virus isolates revealed a strong correlation between resistance to AZT and cross-resistance to Phosphazid. In vitro selection for resistance to Phosphazid yielded viruses that were about 15-fold less sensitive than wild-type virus to this drug. Sequencing of the reverse transcriptase region of seven Phosphazid-selected viruses revealed a single codon mutation, D67N, that is associated with resistance to AZT.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-HIV Agents / pharmacology*
  • Cell Line
  • Drug Resistance, Microbial
  • HIV-1 / drug effects*
  • HIV-1 / genetics
  • Humans
  • Mutation
  • Organophosphonates / pharmacology*
  • Prodrugs / pharmacology*
  • Zidovudine / analogs & derivatives*
  • Zidovudine / pharmacology


  • 3'-azido-2',3'-dideoxythymidine 5'-H-phoshonate
  • Anti-HIV Agents
  • Organophosphonates
  • Prodrugs
  • Zidovudine