title: Treatment outcomes and plasma level of ritonavir-boosted lopinavir monotherapy among HIV-infected patients who had NRTI and NNRTI failure.
abstract: BACKGROUND
  Different strategies of ritonavir-boosted lopinavir monotherapy have been explored; however, data regarding salvage therapy among HIV-infected patients who failed nucleoside reverse transcriptase inhibitor (NRTI) and non-nucleoside reverse transcriptase inhibitor (NNRTI) is still limited.
  
  
  METHODS
  A prospective study was conducted among HIV-infected patients who failed NNRTI-based antiretroviral therapy with M184V, TAMs, and NNRTI mutations, and were naïve to protease inhibitor. LPV/r at 400/100 mg and lamivudine 150 mg were given twice daily. CD4 and HIV-1 RNA were monitored at week 0, 12, 24, and 48. LPV Cmin was assayed for the first 14 patients using HPLC.
  
  
  RESULTS
  There were 40 patients with a mean age of 37 years and 70% were male. Median (IQR) baseline CD4 was 123 (37-245) cells/mm(3) and median (IQR) HIV-1 RNA was 55,800 (9,670-100,000) copies/mL. By intend-to-treat analysis, 30 (75%) and 24 (60%) patients achieved HIV-1 RNA at <400 and <50 copies/mL, respectively. In as-treated analysis, the corresponding rates were 29 (83%) and 23 (67%), respectively. Low-level viral rebound was found in 6 (15%) patients at week 48. Medians CD4 at week 12, 24, 36 and 48 were 249, 283, 307, and 351 cells/mm(3) and significantly changed from baseline (all, P < 0.05). At 6 and 12 weeks, median (min-max) LPV Cmin was 6.52 (1.62-11.64) mg/L and 5.79 (0.75-16.31) mg/L, respectively. There were increments of mean total cholesterol and triglyceride at 48 weeks from baseline (P < 0.05).
  
  
  CONCLUSIONS
  LPV/r monotherapy with recycled lamivudine can maintain virological suppression in a substantial proportion of patients failing NNRTI-based regimen and provides adequate plasma concentrations of LPV although the incidence of low-level viremia is relatively high.
authors.affiliation: Bamrasnaradura Infectious Diseases Institute, Ministry of Public Health, Nonthaburi, 11000, Thailand. drweerawat@hotmail.com
authors.forename: Weerawat
authors.initials: W
authors.lastname: Manosuthi
authors.forename: Sasisopin
authors.initials: S
authors.lastname: Kiertiburanakul
authors.forename: Wannarat
authors.initials: W
authors.lastname: Amornnimit
authors.forename: Wisit
authors.initials: W
authors.lastname: Prasithsirikul
authors.forename: Supeda
authors.initials: S
authors.lastname: Thongyen
authors.forename: Samruay
authors.initials: S
authors.lastname: Nilkamhang
authors.forename: Kiat
authors.initials: K
authors.lastname: Ruxrungtham
authors.forename: Somnuek
authors.initials: S
authors.lastname: Sungkanuparph