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PubMed2005

Clinical pharmacokinetics of nelfinavir and its metabolite M8 in human immunodeficiency virus (HIV)-positive and HIV-hepatitis C virus-coinfected subjects.

In order to evaluate the potential risk of nelfinavir (NFV) accumulation in human immunodeficiency virus (HIV)-hepatitis C virus (HCV)-coinfected patients with liver disease, we investigated the concentrations of NFV and M8, the active metabolite of NFV, in plasma HIV-positive (HIV+) patients coinfected with HCV. A total of 119 HIV+ subjects were included in our study: 67 HIV+ patients, 32 HIV+ and HCV-positive (HCV+) patients without cirrhosis, and 20 HIV+ and HCV+ patients with cirrhosis. Most of the enrolled patients (chronically treated) were taking NFV at the standard dosage of 1,250 mg twice a day. To assay plasma NFV and M8 concentrations, patients underwent serial plasma samplings during the dosing interval at steady state. Plasma NFV and M8 concentrations were measured simultaneously by a high-performance liquid chromatography method with UV detection. The HIV+ and HCV+ patients with and without cirrhosis had significantly lower NFV oral clearances than the HIV+ and HCV-negative individuals (28 and 58% lower, respectively; P < 0.05), which translated into higher areas under the concentration-time curves for cirrhotic and noncirrhotic patients. The NFV absorption rate was significantly lower in cirrhotic patients, resulting in a longer time to the maximum concentration in serum. The mean ratios of the M8 concentration/NFV concentration were significantly lower (P < 0.05) in HIV+ and HCV+ subjects with cirrhosis (0.06 +/- 0.074) than in the subjects in the other two groups. The mean ratios for M8 and NFV were not statistically different between HIV+ and HCV-negative patients (0.16 +/- 0.13) and HIV+ and HCV+ patients without cirrhosis (0.24 +/- 0.17), but the interpatient variability was high. Our results indicate that the pharmacokinetics of NFV and M8 are altered in HIV+ and HCV+ patients, especially those with liver cirrhosis. Therefore, there may be a role for therapeutic drug monitoring in individualizing the NFV dosage in HIV-HCV-coinfected patients.

Adolescent↗
PubMed2002

Modulation of human immunodeficiency virus (HIV)-specific immune response by using efavirenz, nelfinavir, and stavudine in a rescue therapy regimen for HIV-infected, drug-experienced patients.

Analysis of the virologic and immunomodulatory effects of an association of efavirenz (EFV), nelfinavir (NFV), and stavudine (d4T) was performed in 18 human immunodeficiency virus (HIV)-infected and highly active antiretroviral therapy (HAART)-experienced patients who failed multiple therapeutic protocols. Patients (<500 CD4(+) cells/ micro l; >10,000 HIV copies/ml) were nonnucleoside reverse transcriptase inhibitor (NNRTI)-naive and were treated for 10 months with EFV (600 mg/day) in association with NFV (750 mg three times daily) and d4T (30 or 40 mg twice daily). Measurement of HIV peptide- and mitogen-stimulated production of interleukin-2 (IL-2), gamma interferon (IFN-gamma), IL-4, and IL-10 as well as quantitation of mRNA for the same cytokines in unstimulated peripheral blood mononuclear cells were performed at baseline and 2 weeks (t1), 2 months (t2), and 10 months (t3) into therapy. The results showed that HIV-specific (but not mitogen-stimulated) IL-2 and IFN-gamma production was augmented and IL-10 production was reduced in patients who received EFV, NFV, and d4T. Therapy was also associated with a reduction in HIV RNA in plasma and an increase in CD4(+) cell count. These changes occurred in the first year of therapy (t2 and t3) and were confirmed by quantitation of cytokine-specific mRNA. Therapy with EFV, NFV, and d4T increases HIV-specific type 1 cytokine production as well as CD4 counts and reduces plasma viremia. This therapeutic regimen may be considered for use in cases of advanced HIV infection.

Adult↗
PubMed2002

Nelfinavir-resistant, amprenavir-hypersusceptible strains of human immunodeficiency virus type 1 carrying an N88S mutation in protease have reduced infectivity, reduced replication capacity, and reduced fitness and process the Gag polyprotein precursor aberrantly.

The evolution of human immunodeficiency virus type 1 (HIV-1) strains with reduced susceptibility to protease inhibitors (PIs) is a major cause of PI treatment failure. A subset of subjects failing a therapy regimen containing the PI nelfinavir developed mutations at position 88 in the protease region. The N88S mutation occurring in some of these subjects induces amprenavir hypersusceptibility and a reduction of fitness and replication capacity. Here we demonstrate that substitutions L63P and V77I in protease, in combination, partially compensate for the loss of fitness, loss of replication capacity, loss of specific infectivity, and aberrant Gag processing induced by the N88S mutation. In addition, these mutations partially ablate amprenavir hypersusceptibility. Addition of mutation M46L to a strain harboring mutations L63P, V77I, and N88S resulted in a reduction of fitness and infectivity without changing Gag-processing efficiency, while amprenavir hypersusceptibility was further diminished. The ratio of reverse transcriptase activity to p24 protein was reduced in this strain compared to that in the other variants, suggesting that the M46L effect on fitness occurred through a mechanism different from a Gag-processing defect. We utilized these mutant strains to undertake a systematic comparison of indirect, single, cycle-based measures of fitness with direct, replication-based fitness assays and demonstrated that both yield consistent results. However, we observed that the magnitude of the fitness loss for one of the mutants varied depending on the assay used.

Carbamates↗
PubMed2003

Isolation and molecular characterization of a nelfinavir (NFV)-resistant human immunodeficiency virus type 1 that exhibits NFV-dependent enhancement of replication.

During the use of a phenotypic anti-human immunodeficiency virus type 1 (HIV-1) drug resistance assay in a large set of clinical virus isolates, we found a unique variant (CL-4) that exhibited a high level of nelfinavir (NFV) resistance and rather enhanced replication under subinhibitory concentrations of NFV (0.001 to 0.1 micro M). Comparison of gag-pol sequences of the CL-4 variant and its predecessor virus isolates showed a stepwise accumulation of a total of 19 amino acid substitutions in protease (PR) and Gag p17 during 32-month NFV-containing antiretroviral therapy, while other Gag regions including the cleavage sites of the p55 precursor remained highly conserved. To understand the relationship between the genetic and phenotypic changes in CL-4, we constructed chimeric viruses using pNL4-3, replacing the PR, p24PR, or p17PR gene segment of CL-4 or its predecessor. A series of tissue culture infections with the chimeras in the absence or presence of increasing concentrations of NFV demonstrated that only the p17PR segment of CL-4 could confer the NFV-dependent replication enhancement phenotype on NL4-3. Our data suggest a novel adaptation mechanism of HIV-1 to NFV, in which coevolution of Gag and PR genes generates a variant that replicates more efficiently in the cellular environment in the presence of NFV than without the drug.

Blotting, Western↗
PubMed2003

Parameters driving the selection of nelfinavir-resistant human immunodeficiency virus type 1 variants.

We investigated the parameters driving nelfinavir resistance, along the D30N and L90M evolutionary pathways. The advantage of the D30N mutant was mostly due to its resistance level, while the L90M mutation allowed preservation of infectivity coupled with minimal resistance. Emergence of secondary mutations further increased the selective advantage of viruses harboring D30N.

Drug Resistance, Viral↗
PubMed2002

Hepatic and intestinal contributions to pharmacokinetic interaction of indinavir with amprenavir, nelfinavir and saquinavir in rats.

To elucidate the aspects of pharmacokinetic interactions among HIV protease inhibitors (PIs), we investigated the effects of indinavir (IDV) on the hepatic and intestinal first-pass metabolism of other HIV PIs, amprenavir (APV), saquinavir (SQV) and nelfinavir (NFV), in rats. After oral co-administration with IDV, the area under the concentration versus time curves (AUC) of APV, SQV and NFV increased significantly by 1.6-, 9.5- and 2.3-fold, respectively, compared with mono-administration. After intravenous administration, the AUC of APV, SQV and NFV also increased in the presence of IDV by 1.4-, 1.2- and 1.5-fold, respectively. Mean concentrations of APV, SQV and NFV in the liver extracellular fluid, measured using a liver microdialysis method, were very low compared with their Michaelis constants regardless of co-administration of IDV, suggesting that APV, SQV and NFV metabolism follows linear kinetics in the liver. This finding also indicates that metabolism of PIs depended on the metabolic clearance rate in the liver microsomes. The oral bioavailability of SQV in the presence of IDV increased markedly by 8.5-fold, and that of APV and NFV also increased by 1.2- and 1.5-fold, respectively. On the basis of the well-stirred model, the hepatic availabilities of APV, SQV and NFV in the presence of IDV increased by 1.1-, 1.4- and 1.5-fold, and the intestinal availabilities increased by 1.1-, 6.2- and 1.1-fold, respectively. These results suggest that both hepatic and intestinal metabolism were essentially involved in the interactions between IDV and other HIV PIs, and the degree of those contributions varied with each combination of HIV PIs.

Animals↗
PubMedDate not supplied

Probiotics, soluble fiber, and L-Glutamine (GLN) reduce nelfinavir (NFV)- or lopinavir/ritonavir (LPV/r)-related diarrhea.

PURPOSE: Highly active antiretroviral therapy (HAART) can be associated with diarrhea and other gastrointestinal (GI) side effects. Reducing these side effects may improve treatment durability and quality of life (QOL). This study assessed the impact of nutritional co-therapies known to reduce diarrhea in HIV-positive men treated with nelfinavir (NFV)- or lopinavir/ritonavir (LPV/r)-containing regimens. METHODS: Thirty-five HIV-positive men treated with NFV (n = 27) or LPV/r (n = 8) with diarrhea (> or = two liquid stools/day [d]) participated in a 12-week prospective study. Twenty-eight subjects were randomly assigned supplements (S), seven received standard of care (C). Group S received probiotics (1.2g/d) and soluble fiber (11g/d). If diarrhea persisted at week 4, 30g/d L-Glutamine (GLN) was added. Diarrhea incidence, as well as supplement and antidiarrheal use, was assessed monthly. RESULTS: Weight, CD4 count, and HIV RNA were unchanged in both groups. Diarrhea completely resolved in 10 of 28 (36 percent) S subjects. The mean (+/-SD) number of stools/d declined [3.40+/-1.25 to 2.54+/-1.34 (p < 0.01)]. Diarrhea (loose, watery stools/d) lessened in S from 2.84+/-1.42 to 0.74+/-1.03 (p < 0.0001). Fifteen S subjects did not obtain full relief with probiotics and fiber, but stools/d decreased from 4.08+/-1.35 to 3.06+/-1.68 (p < 0.05) after starting GLN. In C, stools/d, 4.14+/-4.86 to 3.44+/-1.68(p = 0.678) and incidence of diarrhea/d, 3.00+/-4.82 to 1.36+/-1.29 (p= 0.361) was unchanged. In S, loperamide use decreased from 1.69+/-2.34 to 0.31+/-0.69 mg/d (p < 0.01); 18 versus eight subjects used loperamide at 0 and 12 weeks, respectively. CONCLUSION: Probiotics, soluble fiber, and GLN significantly reduced diarrhea for subjects receiving NFV or LPV/r. Nutritional co-therapies show clinical benefit in HIV-positive men with diarrhea.

Acquired Immunodeficiency Syndrome↗
PubMed2005

HIV gp41-induced apoptosis is mediated by caspase-3-dependent mitochondrial depolarization, which is inhibited by HIV protease inhibitor nelfinavir.

Apoptotic loss of CD4+ T cells has been proposed as a mechanism of T cell depletion in human immunodeficiency virus (HIV) infections resulting in immunodeficiency. The Env glycoprotein has been implicated in apoptosis of uninfected bystander cells via gp120 binding to CD4/CXC chemokine receptor 4 as well as the fusion/hemifusion process mediated by gp41. Using an in vitro model of coculture of Env-expressing cells as effectors and CD4+ T cells as targets, we find that apoptosis mediated by Env glycoprotein in bystander cells in fact correlates with gp41-induced hemifusion. Further, the apoptotic pathway initiated by this interaction involves caspase-3-dependent mitochondrial depolarization and reactive oxygen species production. HIV gp41-induced mitochondrial depolarization is inhibited by protease inhibitor nelfinavir but not by other HIV protease inhibitors or inhibitors of calpain and cathepsin. This "kiss of death" (hemifusion) signaling pathway is independent of p38 mitogen-activated protein kinase and p53, making it distinct from the apoptosis seen in syncytia. We also show that virion-induced apoptosis is gp41-dependent. Our findings provide new insights into the mechanism via which HIV gp41 mediates apoptosis in bystander cells.

Animals↗
PubMed2003

A comparison of the effects of nevirapine and nelfinavir on metabolism and body habitus in antiretroviral-naive human immunodeficiency virus-infected patients: a randomized controlled study.

New HIV therapies have significantly increased survival, but are associated with multiple metabolic changes, most of them related to the protease inhibitors (PIs). The objective of this study was to elucidate and compare morphological and metabolic alterations in HIV-infected antiretroviral-naive patients receiving two nucleosides plus the PI nelfinavir (NFV) or the nonnucleoside reverse transcriptase inhibitor nevirapine (NVP). Forty-three patients (NFV, n = 20; NVP, n = 23) receiving 6-12 months of treatment were analyzed. Morphological changes were evaluated by bioelectrical impedance analysis, standard anthropometrics, and clinical examination. Serum total cholesterol (TC), low-density and high- density (HDL-c) lipoprotein cholesterol, triglycerides, glucose, and insulin were determined, among other metabolic parameters. No baseline differences were observed between groups. TC increased in both arms (NVP, 11%; NFV, 17%). HDL-c also increased in both groups, although more markedly in those receiving NVP (44% vs. 20%); on-treatment levels were also elevated (1.57 vs. 1.28 mmol/liter). As a consequence of these changes, the TC/HDL-c ratio dropped by 22% in the NVP arm and remained stable in the NFV group. With the use of NFV, the TC/HDL-c ratio and attendant cardiovascular risk did not change. In contrast, NVP offered benefits regarding lipid status, as manifested by enhanced HDL-c concentrations and decreased TC/HDL-c ratios. Inclusion of NVP should be considered when deciding upon antiretroviral regimens for patients at high coronary risk.

Adult↗
PubMed2003

Effect of indinavir on the intestinal exsorption of amprenavir, saquinavir and nelfinavir after intravenous administration in rats.

To elucidate drug interaction between human immunodeficiency virus (HIV) protease inhibitors (PIs), the effect of indinavir (IDV) on the intestinal exsorption of other HIV PIs, amprenavir (APV), saquinavir (SQV) and nelfinavir (NFV) was investigated in rats using an in situ single perfusion method. IDV in the intestinal perfusate inhibited the exsorption of rhodamine 123 (Rho123), a known P-glycoprotein (P-gp) substrate, from blood into intestinal lumen in a concentration-dependent manner, and the inhibitory potency of 10 micro M IDV in the perfusate was close to that of 10 micro M cyclosporin A (CsA) in the perfusate. Ten micro M of IDV in the intestinal perfusate also decreased significantly the exsorption clearance of Rho123 after intravenous administration. The IDV concentration in this system was not likely to cause hepatic interaction between HIV PIs, because the plasma IDV concentration was far below its inhibition constants for other HIV PIs in the liver microsomes. Thus, 10 micro M of IDV was chosen to investigate the effect of this inhibition on the exsorption of APV, SQV and NFV. IDV in the intestinal perfusate markedly increased the exsorbed amounts of SQV and NFV but not APV after intravenous administrations. Their exsorption clearances, however, showed only a slight increasing tendency or remained unchanged. These findings suggest that in addition to P-gp inhibition, other factors such as CYP3A inhibition might be important in the drug interaction of IDV with APV, SQV and NFV after intravenous administration in rat small intestine. The results obtained in this study will provide useful information to discuss the interactions among PIs when a double protease therapy is used for in HIV-infected patients.

Animals↗
PubMedDate not supplied

Nelfinavir plus nevirapine plus two NRTIS as salvage therapy for HIV-infected patients receiving long-term antiretroviral treatment.

PURPOSE: To evaluate a rescue therapy involving nevirapine plus nelfinavir plus two nucleoside reverse transcriptase inhibitors (NRTIs) in patients with prior extensive antiretroviral therapy (AT) including protease inhibitors (PIs) but not nonnucleoside reverse transcriptase inhibitors (NNRTIs). METHOD: Patients with failing regimens were prospectively enrolled. According to genotypic profile at baseline, two groups were identified: a highly resistant (HR) group, which included strains resistant to PI and NRTI, and a moderate nonresistant group (MR), which showed resistance only to PI or NRTI or no resistance. RESULTS: Twenty-two individuals were included. Average time of AT prior to enrollment was 3.7 years (range 1.4-7.6), median viral load 4.92 log(10) (interquartile range [IQR] 1.63 log(10)), and median CD4 cell count 64 cells/microL (IQR 94). After 16 weeks of treatment, seven patients (31%) achieved virological response, five of them (22.7%) with <500 c/mL (bDNA). Fourteen patients were studied for resistance. The HR group showed a poorer response than the MR group (0 vs. 7 responses; p =.034). CONCLUSION: We found a virological response in 31% of our patients, and mainly in those of the MR group some presented previous intolerance. These two factors probably reflect the number of drugs included in the rescue therapy to which the patient is sensitive. Treatment history as well as genotypic resistance assays are useful in identifying patients with the best chance of responding.

Adult↗
PubMedDate not supplied

Comparison of two once-daily regimens with a regimen consisting of nelfinavir, didanosine, and stavudine in antiretroviral therapy-naïve adults: 48-week results from the Antiretroviral Regimen Evaluation Study (ARES).

BACKGROUND: To improve the dosing frequency and pill burden of antiretroviral therapy, we compared two once-daily dosed regimens to a twice-daily dosed regimen. METHOD: HIV-1-infected, antiretroviral drug-naïve adults were randomized to either twice-daily nelfinavir and stavudine and once-daily didanosine (regimen A) or simplified once-daily dosed antiretroviral regimens consisting of nevirapine, didanosine, and lamivudine (regimen B) or saquinavir, ritonavir, didanosine, and lamivudine (regimen C). RESULTS: At 48 weeks of therapy, the proportion of patients with a blood plasma HIV-1 RNA concentration (pVL) <50 copies/mL by intention-to treat analysis was 42.3%, 50.0%, and 56.5% for regimens A (n = 26), B (n = 22), and C (n = 23), respectively. The time to a pVL <50 copies/mL for the first time was significantly shorter in regimen C, and there was significantly more progression to CDC events in regimen B. These differences are possibly due to differences in baseline characteristics. Adverse events were lowest for regimen C; more signs associated with mitochondrial toxicity occurred in regimen A. Increase in CD4 count was comparable between arms. CONCLUSION: No statistically significant difference in efficacy was found between the two investigated once-daily dosed treatment regimens (B and C) and the reference (A). Regimen C possibly had a better virological response and less toxicity than regimens A and B.

Adult↗
PubMedDate not supplied

Health-related quality of life in HIV-infected naive patients treated with nelfinavir or nevirapine associated with ZDV/3TC (the COMBINE-QoL substudy).

PURPOSE: The aim of the study was to assess differences in health-related quality of life (HRQoL) in HIV-infected naive patients treated with two HAART regimens at 12 months. METHOD: The MOS-HIV questionnaire was used to measure HRQoL in a subgroup of 127 patients included in the COMBINE study, which was an open-label, randomized, multicenter study comparing zidovudine (ZDV) and lamivudine (3TC) plus nelfinavir (NFV) or nevirapine (NVP) regimens in HIV-infected naive patients. 63 patients were included in the ZDV/3TC/NFV arm and 64 in the ZDV/3TC/NVP arm. RESULTS: No statistically significant differences were observed at baseline in demographic and clinical variables and HRQoL scores between treatment groups, except that the proportion of homosexual men was higher in the ZDV/3TC/NVP arm. There were no statistically significant differences in HRQoL scores between arms at 12 months and over time; only ZDV/3TC/NVP patients showed statistically significant improvement in Physical Health Summary score (p <.01) and a trend toward a better profile in Mental Health Summary score (p =.07). Overall, patients who were treated with ZDV/3TC/NVP showed greater changes in physical dimensions and patients who were treated with ZDV/3TC/NFV showed greater changes in mental health. CONCLUSION: Differences in HRQoL between study groups at 1 year follow-up were not detected. Nevertheless, a trend toward improvement was observed in summary health scores in ZDV/3TC/NVP-treated patients.

Adult↗
PubMedDate not supplied

A randomized clinical trial comparing nelfinavir and ritonavir in patients with advanced HIV disease (CPCRA 042/CTN 102).

PURPOSE: To compare the long-term clinical efficacy and toxicity of initial strategies of nelfinavir (NFV) or ritonavir (RTV) in patients with CD4+ cells below 200/mm3. METHOD: This was an open-label randomized multicenter trial (CPCRA, CTN). Patients were naïve to protease inhibitor use except for hard gel saquinavir. Patients who were intolerant to their assigned therapy were allowed to switch arms (later RTV-intolerant patients could switch to indinavir). The primary objective was to compare the regimens for AIDS-defining conditions and death (AIDS/death) using intent-to-treat analysis. Hazard ratios (HR) for NFV and RTV were estimated using Cox's proportional hazards models. Kaplan-Meier life table summaries were also used to compare the two groups. RESULTS: There were 775 patients who were randomized beginning in January 1997 and followed through December 2001. At entry, mean CD4+ cell count was 58 cells/mm3 and HIV RNA level averaged 4.9 log copies/mL. After a median follow-up of 52 months, rates of AIDS/death were 12.7 and 11.0 per 100 person years for the NFV and RTV groups, respectively (HR=1.16; 95% CI, 0.92-1.46; p=.21). Discontinuations occurred earlier in the RTV group (p=.0001). CONCLUSION: There are moderate differences in efficacy and large differences in tolerability between a strategy of initial NFV or RTV in patients with advanced disease. Finding the right balance between potency and tolerability remains a challenge.

Adult↗
PubMedDate not supplied

Cost-effectiveness of lopinavir/ritonavir versus nelfinavir as the first-line highly active antiretroviral therapy regimen for HIV infection.

PURPOSE: Selecting the optimal treatment regimen for antiviral-naive patients may be difficult, given the concern about the antiviral activity, the development of drug resistance, and the increase in drug costs. This study evaluates the costs and effectiveness of using lopinavir/ritonavir (LPV/r) vs. nelfinavir (NFV), both coadministered with stavudine and lamivudine, as the first HAART regimen in treating HIV patients, based on the results from the published clinical trial M98-863. METHOD: A Markov model was developed using a combination of viral load (VL) and CD4 count as surrogate markers to define health states. VL and CD4 count data from the 48-week analysis of the clinical trial were used as measures of effect. The impact of resistance difference between NFV and LPV/r was also examined. RESULTS: Over the first 5 years, the model estimated that LPV/r could save $3,461 USD per patient in total HIV care costs compared with NFV. If the resistance advantage of LPV/r was taken into account, the cost savings by LPV/r increased to $5,546 USD. For longer term projection, without considering the resistance difference, the incremental cost-effectiveness ratio (CER) for LPV/r vs. NFV was $6,653 USD per quality-adjusted life-year (QALY). This CER compares favorably to therapies for HIV disease and for common drug treatments for other conditions and is well within accepted thresholds for health policy makers. CONCLUSION: When treatment options are being considered, this study suggests that use of LPV/r in the first antiretroviral regimen, as compared to NFV, is cost-effective based on improved efficacy and resistance.

Adult↗
PubMed2006

A review of nelfinavir for the treatment of HIV infection.

Nelfinavir (NFV) is a protease inhibitor that has been widely used for several years for the treatment of HIV infection. This has led to extensive experience with NFV-containing regimens, in which the drug has shown prolonged viral suppression, good tolerability and a unique resistance profile. In recent years, several antiretroviral drugs with some advantages over NFV have been developed. Nevertheless, NFV has favourable characteristics that make it a suitable antiretroviral compound for many HIV-infected patients. It can be used in patients who do not tolerate ritonavir even at low doses, and it is well tolerated in pregnant women, has a low-grade interaction with methadone and may be well tolerated in hepatitis C virus-co-infected patients. In addition, its new simplified posology may contribute to improved adherence.

Female↗
PubMed2003

Nelfinavir pharmacokinetics in stable human immunodeficiency virus-positive children: Pediatric AIDS Clinical Trials Group Protocol 377.

OBJECTIVE: Pharmacokinetic data obtained from children who have human immunodeficiency virus (HIV) infection are essential for the safe and effective use of antiretroviral agents in pediatric populations. The objective of this study was to assess the impact of body weight on the pharmacokinetic disposition of nelfinavir (NFV) in the absence and presence of nevirapine (NVP) and compare the pharmacokinetic profiles of twice-daily (BID) and three-times-daily (TID) NFV regimens. METHODS: This was an intensive pharmacokinetic substudy nested in a phase II, multicenter, randomized, open-label trial. Forty-five HIV-infected children receiving NFV 30 mg/kg TID and 6 HIV-infected children receiving NFV 55 mg/kg BID were enrolled in this study and assigned to 1 of 4 stavudine-containing regimens, 3 containing NFV and 2 containing NVP. Area under the plasma concentration-time curves from 0 to 8 hours (AUC(0-8 hours)) and from 0 to 12 hours (AUC(0-12 hours)) for the TID and BID regimens, respectively, were determined. For comparative purposes, the AUC(0-24 hours) was also calculated for each regimen. RESULTS: NFV exposure in the absence of NVP was decreased in children who were <25 kg compared with those who were >25 kg (a 2.6-fold difference in median AUC(0-8 hours)). NFV pharmacokinetics in the presence of NVP did not differ between the <25 kg and >25 kg groups. The AUC(0-24 hours) for children who were <30 kg and on NFV BID was comparable to the AUC(0-24 hours) for children who were >25 kg and on NFV TID but was 2.7-fold greater than AUC(0-24 hours) for children who were <25 kg and on NFV TID. CONCLUSIONS: NFV in the absence of NVP resulted in less than half the drug exposure in children who were <25 kg compared with children who were >25 kg. NFV dosed at 55 mg/kg BID in children who are <30 kg provides comparable exposure to that measured in children who are >25 kg and receiving NFV 30 mg/kg TID.

Acquired Immunodeficiency Syndrome↗
PubMed2006

Long-term experience with combination antiretroviral therapy that contains nelfinavir for up to 7 years in a pediatric cohort.

OBJECTIVE: We sought to provide long-term data on the clinical, immunologic, and virologic response to highly active antiretroviral therapy in infants and children who are naive to protease inhibitors. METHODS: HIV-1-infected children who were naive to protease inhibitors were treated with a combination of nelfinavir and 2 nucleoside reverse transcriptase inhibitors (stavudine and lamivudine) in an observational, prospective, single-center study. Virologic failure-free survival was assessed by Kaplan-Meier analyses. The increase in CD4+ T cells during follow-up was estimated with a generalized linear model incorporating repeated measurements. RESULTS: Thirty-nine HIV-1-infected children were included and followed for a median period of 227 weeks (interquartile range: 108-275 weeks). The virologic failure-free survival rate was 74%, 66%, 58%, and 54% after 48, 96, 144, and 240 weeks, respectively. Children who experienced virologic failure in 48 weeks (or 96 weeks) were younger at baseline compared with the responders (0.8 vs 5.3 years). Eighteen children remained on the regimen for >5 years. All children, including the nonresponders, showed a sustained immunologic response. Grades 3 to 4 toxicity was observed in 2 patients only. Eleven developed clinically evident lipodystrophy. CONCLUSION: Combination therapy can be used safely in infants and children over a long period. Young age is strongly associated with virologic failure. Although the virologic response declined, immunologic parameters and clinical improvement were sustained up to 7 years, at the expense of lipodystrophy.

Antiretroviral Therapy, Highly Active↗