Patients will be enrolled in this study for 96 weeks and will be randomly assigned into one of two groups. Group 1 will receive LPV/r and 2 NRTIs. Treatment naive patients in Group 1 will have the option of receiving either once-daily dosing or twice-daily dosing of LPV/r. Treatment experienced patients will receive twice-daily dosing of LPV/r. Patients on once-daily dosing of LPV/r who become intolerant to the regimen will be permitted to switch to twice-daily dosing. Group 2 will receive EFV and 2 NRTIs. All patients will be independently and simultaneously randomly assigned to undergo either TDM with subsequent dose adjustment if necessary or no TDM.