Evaluation of Renal Function, Efficacy, and Safety When Switching From Tenofovir/Emtricitabine Plus a Protease Inhibitor/Ritonavir, to a Combination of Raltegravir (MK-0518) Plus Nevirapine Plus Lamivudine in HIV-1 Participants With Suppressed Viremia and Impaired Renal Function (MK-0518-284)

Percentage of Participants With Suppressed Viremia (<50 Copies/mL HIV-1 Ribonucleic Acid [RNA]) at Week 48

Plasma was to be collected at Week 48 in order to quantify HIV-1 RNA. and identify the percentage of participants with \<50 copies/mL HIV-1 RNA.

Time frame: Week 48

Percentage of Participants With Suppressed Viremia (<50 Copies/mL HIV-1 RNA) at Week 96

Plasma was to be collected at Week 96 in order to quantify HIV-1 RNA. and identify the percentage of participants with \<50 copies/mL HIV-1 RNA.

Time frame: Week 96

Percentage of Participants With Decline in Renal Function at Week 48

Decline in renal function was to be assessed by evaluating MDRD-6, creatinine clearance and serum phosphate.

Time frame: Week 48

Percentage of Participants With Virologic Failure (HIV-1 RNA > 50 Copies/mL)

Plasma was to be collected up to Week 96 in order to quantify HIV-1 RNA, and identify the percentage of participants with \>50 copies/mL HIV-1 RNA.

Time frame: Up to Week 96

Change From Baseline of HIV-RNA Absolute Values

Plasma was to be collected at baseline and Week 96 in order to determine the change from baseline in HIV-1 RNA.

Time frame: Baseline and Week 96

Percentage of Participants With Mutations Associated With Resistance to NRTIs, NNRTIs, INI, at Virological Failure.

Participants were to be identified with mutations associated with Nucleoside/ Nucleotide Reverse Transcriptase Inhibitors (NRTIs), Non-nucleoside Reverse Transcriptase Inhibitors (NNRTIs), and Integrase Inhibitor (INI). Virological failure is defined as 2 consecutive plasma HIV-1 RNA \>200 copies/mL at least two weeks apart while on previous or current ARV therapy.

Time frame: Up to Week 96

Change From Baseline in Absolute CD4+ T-lymphocyte Count

Cluster of Differentiation 4 + (CD4+) T-lymphocyte cell counts were to be determined at baseline and Week 96, in order to determine the change from baseline.

Time frame: Baseline and Week 96

Percentage of Participants With Altered Liver Enzymes and Lipid Profile

Values of liver enzymes and lipids were to be determined from laboratory tests, in order to identify the percentage of participants classified with altered values.

Time frame: Up to Week 96

Percentage of Participants With Altered Values of Tubular Kidney Injury Markers.

Values of tubular kidney injury markers. were to be determined, in order to identify the percentage of participants classified with altered values.

Time frame: Up to Week 96

Percentage of Participants Having Changes From Baseline in Metabolic Bone Markers

Changes from baseline in metabolic bone markers, serum Bone Specific Alkaline Phosphatase (s-BSAP) and C-telopeptides of type 1 Collagen (s-CTx), were to be determined, in order to classify the percentage of participants with changes.

Time frame: Baseline and up to Week 96

Area Under the Concentration Time Curve From Time 0 the Last Measurement Time t (AUC0-t) for Raltegravir and Nevirapine

Blood samples were to be collected in Week 12 in order to use the trapezoidal method to determine the AUC0-t of Raltegravir and Nevirapine

Time frame: Week 12: Fasted state (0 h) and 1, 2, 3, 6 and 12 h post-dose

Trough Concentration (Ctrough) for Raltegravir and Nevirapine

Blood samples were to be collected in Weeks 12 and 48 in order to use the trapezoidal method to determine the Ctrough, the lowest concentration reached by the drug before the next dose is administered, of Raltegravir and Nevirapine.

Time frame: Weeks 12 and 48: at the end of dosing interval at 12 h

Percentage of Participants With Genotypic Resistance at Virologic Failure.

Genotypic resistance measures the presence of particular HIV-1 mutations that give rise to drug resistance. Virological failure is defined as 2 consecutive plasma HIV-1 RNA \>200 copies/mL at least two weeks apart while on previous or current ARV therapy.

Time frame: Up to Week 96

Percentage of Participants With Adherence to Study Therapy

An Adherence Questionnaire was to be given in order to determine the percentage of participants who adhered to study therapy.

Time frame: Up to Week 96

Change From Baseline in Bone Disease Risk Assessment

Bone disease risk assessment was to be based on a Fracture Risk Assessment Tool (FRAX®) score in participants \> 40 years old, and the change from baseline determined.

Time frame: Baseline and week 96

Change From Baseline in the VACS Index

The Veterans Aging Cohort Risk Index (VACS Index) combines various clinical biomarkers into a cumulative index weighted according to the risk of all-cause mortality.

Time frame: Baseline and week 96

Percentage of Participants Experiencing a Decline of Renal Function

Decline in renal function was to be assessed by evaluating MDRD-6, creatinine clearance and serum phosphate.

Time frame: Up to Week 96

Change From Baseline in eGFR at Week 96

Glomerular Filtration Rate (eGFR) was estimated from the Modification of Diet in Renal Disease (MDRD)-6 equation. The MDRD-6 equation = 198 × \[serum creatinine(mg/dL)\]\^-0.858 × \[age\]-0.167 × \[0.822 if patient is female\] × \[1.178 if patient is black\] × \[serum urea nitrogen concentration (mg/dL)\]\^-0.293 × \[urine urea nitrogen excretion (g/d)\]\^0.249.

Time frame: Baseline and Week 96