APTIVUS, co-administered with ritonavir, is indicated for combination antiretroviral treatment of HIV-1 infected patients who are treatment-experienced and infected with HIV-1 strains resistant to more than one protease inhibitor . This indication is based on analyses of plasma HIV-1 RNA levels in two controlled studies of APTIVUS/ritonavir of 48 weeks duration in treatment-experienced adults and one open-label 48-week study in pediatric patients age 2 to 18 years. The adult studies were conducted in clinically advanced, 3-class antiretroviral treatment-experienced adults with evidence of HIV-1 replication despite ongoing antiretroviral therapy. The following points should be considered when initiating therapy with APTIVUS/ritonavir: The use of APTIVUS/ritonavir in treatment-naïve patients is not recommended [ see Warnings and Precautions.