Reasons to consider changing an anti-retroviral regimen:
(1) failure to achieve the expected reduction in HIV RNA levels
(1a) less than a 1 LOG10 reduction by 8 weeks after starting therapy
(1b) repeated HIV RNA > 400 copies per mL after 24 weeks
(1c) repeated HIV RNA > 50 copies/mL by 48 weeks
(2) >= 3 fold increase in plasma HIV RNA from the nadir not attributable to intercurrent infection, vaccination or test methodology, detected on repeated samples
(3) undetectable viremia in a patient receiving double nucleoside therapy (2 NRTI) because of risk of subsequent resistance occurring
(4) failure related to numbers of CD4+ T lymphocytes
(4a) persistently declining CD4+ T cell numbers measured on at least 2 separate occasions
(4b) failure to increase the CD4 cell count by 25-50 cells per µL from baseline over the first year of therapy
(5) disease progression with clinical deterioration while on the regimen
Additional reasons why a regimen may have to be changed:
(1) development of unacceptable side effects
(2) inability to adhere to a complex regimen
