Clinical impact of the M184V mutation on switching to didanosine or maintaining lamivudine treatment in nucleoside reverse-transcriptase inhibitor-experienced patients.

Virologic outcome among 104 lamivudine (3TC)-experienced individuals infected with human immunodeficiency virus type 1 who switched to a didanosine (ddI)-containing triple- or quadruple-drug regimen was compared with those who continued receiving a 3TC-containing regimen. A significantly increased independent risk of virologic failure was associated with continuing a 3TC-containing regimen. In addition, most patients for whom the ddI-containing regimen failed lost the M184V/I mutation. These results show that ddI continues to provide activity against viruses with the M184V/I mutation and suggest that the presence of the M184V/I mutation should not preclude the use of ddI in nucleoside-experienced patients.