Renal impairment in HIV-1 infected patients receiving antiretroviral regimens including tenofovir in a resource-limited setting.

A retrospective cohort study was conducted among HIV-1 infected patients taking tenofovir as part of an anti-HIV drug regimen in a resource-limited setting in Thailand. One hundred thirty patients with a mean_SD age of 39.7+/-7.4 years, of whom 55% were male, were included in the study. Fifty-eight (45%), 48 (37%), and 24 (18%) patients concurrently received nevirapine-based, efavirenz-based, and protease inhibitor (PI)-based regimens, respectively. The median (IQR) value for serum creatinine was 0.8 (0.6-0.9) mg/dl, for eGFR was 103 (96-120) ml/min/1.73 m2 and for CD4 was 302 (194-511) cells/mm3 at the time of tenofovir initiation. At 3-6 months, the median (IQR) eGFR was 100 (88-117) ml/min/1.73 m2 (p=0.002, compared to baseline). The proportions of patients with an estimated glomerular filtration rate (eGFR)<30 ml/min/1.73 m2 at baseline and 3-6 months were 0% and 2%, respectively (p<0.001). At 6-months follow-up, 2 patients (1.4%) were diagnosed with acute renal failure at 3 weeks and 9 weeks after tenofovir use, respectively. Both patients received a boosted PI in the regimen. Overall, the incidence of acute renal failure was 0.26 per 100 person-months. Renal function progressed to irreversible renal failure in one patient. In summary, tenofovir-associated renal impairment is not uncommon in a real-life practice. This report highlights the potentially irreversible adverse effect of this agent, particularly in patients with vulnerable kidneys and concomitant use of tenofovir and boosted PI.

Treatment outcomes of patients co-infected with HIV and tuberculosis who received a nevirapine-based antiretroviral regimen: a four-year prospective study.

BACKGROUND: The concurrent use of nevirapine-based antiretroviral therapy (ART) and rifampin-containing anti-tuberculosis regimens for the treatment of HIV and tuberculosis (TB) is common in resource-limited countries. Long-term outcomes of this concurrent treatment are unknown. METHODS: Seventy HIV-infected patients receiving rifampin for active TB (TB group) and 70 HIV-mono-infected patients (control group) were enrolled to receive nevirapine 400mg/day-based ART. All were followed through 4 years of ART. Plasma HIV-1 RNA and CD4 cell counts were monitored every 12 weeks until 96 weeks, and every 24 weeks thereafter. RESULTS: Of the 140 patients, the median (interquartile range (IQR)) CD4 count was 31 (14-79) cells/mm(3) and median (IQR) plasma HIV-1 RNA was 5.6 (5.2-5.9) log copies/ml at baseline . Thirty-nine (55.7%) patients in the TB group were diagnosed with extrapulmonary/disseminated TB. The median duration of concurrent administration of nevirapine and rifampin was 5.4 (4.6-6.1) months. By intention-to-treat analysis, the percentage of patients who achieved HIV-1 RNA <50 copies/ml was 52.9% in the TB group and 50% in control group (p=0.866; odds ratio 1.121, 95% confidence interval 0.578-2.176); median (IQR) CD4 counts were 352 (271-580) cells/mm(3) and 425 (308-615) cells/mm(3) in the corresponding groups (p=0.238). The proportion of ART discontinuation due to any reason at 1, 2, 3, and 4 years was 21%, 34%, 37%, and 46% in the TB group and 21%, 36%, 43%, and 49% in the control group, respectively (p=0.651). The 4-year mortality rate was 6.4% in both groups. CONCLUSIONS: Nevirapine-based ART is an option for HIV-infected patients who receive rifampin in resource-limited countries or those who cannot tolerate efavirenz.

Renal impairment after switching from stavudine/lamivudine to tenofovir/lamivudine in NNRTI-based antiretroviral regimens.

BACKGROUND: During stavudine phase-out plan in developing countries, tenofovir is used to substitute stavudine. However, knowledge regarding whether there is any difference of the frequency of renal injury between tenofovir/lamivudine/efavirenz and tenofovir/lamivudine/nevirapine is lacking. METHODS: This prospective study was conducted among HIV-infected patients who were switched NRTI from stavudine/lamivudine to tenofovir/lamivudine in efavirenz-based (EFV group) and nevirapine-based regimen (NVP group) after two years of an ongoing randomized trial. All patients were assessed for serum phosphorus, uric acid, creatinine, estimated glomerular filtration rate (eGFR), and urinalysis at time of switching, 12 and 24 weeks. RESULTS: Of 62 patients, 28 were in EFV group and 34 were in NVP group. Baseline characteristics and eGFR were not different between two groups. At 12 weeks, comparing mean ± SD measures between EFV group and NVP group were: phosphorus of 3.16 ± 0.53 vs. 2.81 ± 0.42 mg/dL (P = 0.005), %patients with proteinuria were 15% vs. 38% (P = 0.050). At 24 weeks, mean ± SD phosphorus and median (IQR) eGFR between the corresponding groups were 3.26 ± 0.78 vs. 2.84 ± 0.47 mg/dL (P = 0.011) and 110 (99-121) vs. 98 (83-112) mL/min (P = 0.008). In NVP group, comparing week 12 to time of switching, there was a decrement of phosphorus (P = 0.007) and eGFR (P = 0.034). By multivariate analysis, 'receiving nevirapine', 'old age' and 'low baseline serum phosphorus' were associated with hypophosphatemia at 24 weeks (P < 0.05). Receiving nevirapine and low baseline eGFR were associated with lower eGFR at 24 weeks (P < 0.05). CONCLUSION: The frequency of tenofovir-associated renal impairment was higher in patients receiving tenofovir/lamivudine/nevirapine compared to tenofovir/lamivudine/efavirenz. Further studies regarding patho-physiology are warranted.

Body weight cutoff for daily dosage of efavirenz and 60-week efficacy of efavirenz-based regimen in human immunodeficiency virus and tuberculosis coinfected patients receiving rifampin.

Seventy-one human immunodeficiency virus-infected patients with tuberculosis who were receiving a rifampin (rifampicin)-containing regimen were initiated on treatment with efavirenz at 600 mg/day plus stavudine-lamivudine. Fasting efavirenz concentrations at 12 h after dosing (C12) were monitored. The mean +/- standard deviation efavirenz C12 at weeks 6 and 12 and after rifampin discontinuation were 4.5 +/- 4.3, 3.8 +/- 3.5, and 3.5 +/- 2.7 mg/liter, respectively. High body weight was associated with a low efavirenz C12 at weeks 6 and 12 (P = 0.003, r = -0.255). The efavirenz C12 regression prediction line at 1 mg/liter intercepted a mean body weight of 57.5 kg.

A randomized trial comparing plasma drug concentrations and efficacies between 2 nonnucleoside reverse-transcriptase inhibitor-based regimens in HIV-infected patients receiving rifampicin: the N2R Study.

BACKGROUND: To our knowledge, to date, no prospective, randomized, clinical trial has compared standard doses of efavirenz- and nevirapine-based antiretroviral therapy among patients with concurrent human immunodeficiency virus type 1 (HIV-1) infection and tuberculosis (TB) who are receiving rifampicin. METHODS: Rifampicin recipients with concurrent HIV-1 infection and TB were randomized to receive antiretroviral therapy that included either efavirenz (600 mg per day) or nevirapine (400 mg per day). Efavirenz and nevirapine concentrations at 12 h after dosing (C12) were monitored at weeks 6 and 12. CD4+ cell counts and HIV-1 RNA levels were assessed every 12 weeks. RESULTS: One hundred forty-two patients were randomized into 2 groups equally. The mean body weight of patients was 53 kg, the mean CD4+ cell count was 65 cells/mm3, and the median HIV-1 RNA level was 5.8 log10 copies/mL. At weeks 6 and 12, the mean C12 of efavirenz (+/- standard deviation) were 4.27+/-4.49 and 3.54+/-3.78 mg/L, respectively, and those for nevirapine were 5.59+/-3.48 and 5.6+/-2.65 mg/L, respectively. Interpatient variability in the efavirenz group was 2.3-fold greater than that in the nevirapine group (coefficient of variation, 107% vs. 47%). At week 12, 3.1% of patients in the efavirenz group and 21.3% in the nevirapine group had C12 values that were less than the recommended minimum concentrations (odds ratio, 8.396; 95% confidence interval, 1.808-38.993; P= .002). Intention-to-treat analysis revealed that 73.2% and 71.8% of patients in the efavirenz and nevirapine groups, respectively, achieved HIV-1 RNA levels <50 copies/mL at week 48, with respective mean CD4+ cell counts of 274 and 252 cells/mm3 (P> .05). Multivariate analysis revealed that patients with low C12 values and those with a body weight <55 kg were 3.6 and 2.4 times more likely, respectively, to develop all-cause treatment failure (P< .05). CONCLUSIONS: Antiretroviral therapy regimens containing efavirenz (600 mg per day) were less compromised by concomitant use of rifampicin than were those that contained nevirapine (400 mg per day) in patients with concurrent HIV-1 infection and TB. Low drug exposure and low body weight are important predictive factors for treatment failure.

Durability of stavudine, lamivudine and nevirapine among advanced HIV-1 infected patients with/without prior co-administration of rifampicin: a 144-week prospective study.

BACKGROUND: To date, data on the durability of a regimen of stavudine, lamivudine and nevirapine are very limited, particularly from the resource-limited settings. METHODS: A prospective cohort study was conducted among 140 antiretroviral-naïve patients who were enrolled to initiate d4T, 3TC and NVP between November 2004 and March 2005. The objectives were to determine immunological and virological responses after 144 weeks of antiretroviral therapy. Seventy patients with tuberculosis also received rifampicin during the early period of antiviral treatment (TB group). RESULTS: Of all, median (IQR) baseline CD4 cell count was 31 (14-79) cells/mm3; median (IQR) baseline HIV-1 RNA was 433,500 (169,000-750,000) copies/mL. The average body weight was 55 kilograms. By intention-to-treat analysis at 144 weeks, the overall percentage of patients who achieved plasma HIV-1 RNA <50 copies/mL was 59.3% (83/140). In subgroup analysis, 61.4% (43/70) patients in TB group and 57.1% (40/70) patients in control group achieved plasma HIV-1 RNA <50 copies/mL (RR = 1.194, 95%CI = 0.608-2.346, P = 0.731). Eight (5.8%) patients discontinued d4T due to neuropathy and/or symptomatic lactic acidosis. CONCLUSION: The overall durability and efficacy of antiviral response of d4T, 3TC and NVP are satisfied and they are not different between HIV-1 infected patients with and without co-administration of rifampicin due to tuberculosis. However, stavudine-related adverse effects are concerns. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT00703898.