Open Access

Poster presentation: Background In the past years, once-daily (QD) dosing of antiretroviral combination therapy has become an increasingly available treatment option for HIV-1+ patients. Methods Open label study in which HIV-1+ patients treated with SAQ/RTV (1000/100 mg BID) and two NRTIs with HIV-RNA-PCR < 50 copies/ml were switched to SAQ/RTV(2000/100 mg QD) with unchanged NRTI-backbone. CD4-cells, HIV-RNA-PCR, SAQ and RTV drug-levels and metabolic parameters were compared. Summary of results 17 patients (15 male, 42 years), median CD4 456 ± 139/micro l were included so far. The median follow-up time is 4 months. The HIV-RNA-PCR remained <50 copies/ml for all patients. Fasting metabolic parameters remained unchanged. The SAQ AUC 0–12 h were significantly higher when given QD vs. BID (median 29,400 vs. 18,500 ng*h/ml; p = 0.009), whereas the Cmin, Cmax and AUC was lower for RTV when given QD vs. BID (7,400 vs. 11,700 ng*h/ml; p = 0.02). Conclusion In this ongoing study SAQ/RTV (2000/100 mg QD) was well tolerated and demonstrated higher SAQ and lower RTV drug levels as compared to the BID dosing schedule. (Table 1 and Figure 1.)