After 48 weeks of treatment with Kaletra, efavirenz and nucleoside reverse transcriptase inhibitors, plasma HIV RNA ≤ 400 copies/ ml was observed in 93% (25/ 27), 73% (11/ 15), and 25% (2/ 8) of patients with< 10-fold, 10 to 40-fold, and > 40-fold reduced susceptibility to lopinavir at baseline, respectively.