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PubMed2005

Pharmacokinetics and pharmacodynamics of low dose mycophenolate mofetil in HIV-infected patients treated with abacavir, efavirenz and nelfinavir.

BACKGROUND: The use of mycophenolate mofetil in combination with highly active antiretroviral therapy (HAART) has been proposed in order to inhibit HIV replication. Due to the low doses involved, pharmacokinetic-pharmacodynamic monitoring is recommended. OBJECTIVE: The aim of this study was to characterise the pharmacokinetic and pharmacodynamic monitoring of low doses of mycophenolate mofetil (0.25 g twice daily) in HIV-infected patients treated with HAART and after programmed discontinuation of HAART, in order to assess whether low doses of this immunosuppressive agent provide a biological effect. METHODS: Mycophenolic acid (MPA) plasma levels (assessed by high-performance liquid chromatography) and the capacity of patients' sera to inhibit CEM cell line proliferation (assessed by (3)H-thymidine uptake) were measured post-dose at 0, 20, 40 minutes and 1, 2, 4, 6, 8, 10 and 12 hours in nine HIV-infected patients treated with a combination of abacavir, nelfinavir and efavirenz (HAART) and mycophenolate mofetil 0.25 g twice daily at days 7, 28, 120 and 150 (30 days without HAART) after the treatment initiation. A control group of eight patients was treated with HAART alone. RESULTS: In the 35 post-dose curves analysed, no differences were found in MPA levels between days 7, 28, 120 and 150: area under the plasma concentration-time curve - mean value 15.3 mg . h/L, range 10.4-24.4 mg . h/L; minimum plasma concentration - mean value 0.60 mg/L, range 0.20-4.67 mg/L; maximum plasma concentration mean value 2.60 mg/L, range 0.94-7.98 mg/L. Pretreatment patients' sera did not inhibit CEM proliferation. Post-treatment patients' sera inhibited CEM proliferation to <40% in 25 of 35 curves at 0 hours (six of nine patients), in 34 of 35 curves at 1 hour, in 32 of 35 curves at 2 hours, in 22 of 35 curves at 4 hours, and in 8 of 35 curves at 12 hours. The MPA level versus CEM proliferation inhibition had a concentration that produces 50% of the maximum drug effect (EC(50)) of 0.33 mg/L. Viral load at day 150 was >200 copies/mL in all control patients and in three of nine patients receiving mycophenolate mofetil. These three patients were the only ones repeatedly unable to inhibit pre-dose CEM proliferation to <40%. CONCLUSIONS: Mycophenolate mofetil pharmacokinetic profiles in HIV patients under HAART are not significantly different from those found in transplant patients. Sera from the majority of patients receiving low doses of mycophenolate mofetil inhibited lymphocyte proliferation during most of the inter-dose interval, despite low MPA plasma levels. For some patients, higher doses may be necessary: the capacity of sera to inhibit CEM proliferation may help to identify these patients.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Therapeutic drug monitoring of saquinavir in patients during protease inhibitor therapy with saquinavir alone or in combination with ritonavir or nelfinavir.

Therapeutic drug monitoring is essential in HIV-patients undergoing highly active antiretroviral therapy (HAART). Saquinavir (SQV) is used alone or in combination with ritonavir (RTV) or nelfinavir (NLF), respectively, in the context of the HAART drug regimen. The achievable SQV concentration range in clinical practice remains to be elucidated. A non-randomized prospecitve clinical trial 19 patients (group I) receiving SQV (1x600 mg/d Invirase or Fortovase), 29 patients (group II) receiving SQV (2x600 mg/d Fortovase) plus RTV (2x400 mg/d Norvir), and 21 patients (group III) receiving SQV (2x600 mg/d Fortovase) plus NLF (2x750 mg/d Viracept) was conducted to determine SQV plasma concentrations. SQV levels were determined as trough levels during routine outpatient visits. Analysis was performed by HPLC with UV detection. The lowest SQV plasma levels were found in group I (95% CI 89-177 ng/ml). Significantly higher SQV levels were found in group III (combination with NLF) ranging from 242 to 398 ng/ml (95% CI) and in group II (combination with RTV) ranging from 1354 to 1747 ng/ml (95% CI). The IC 50% of 54 ng/ml was not reached in at least one sample during the study (mean duration of study 16+/-10 months) in 14/19 patients of group I, 9/29 patients in group II and 13/21 patients in group III, respectively. A positive correlation between patient compliance, defined by SQV levels in the 95% CI of the used combination, and the HIV RNA plasma level was found. The presented data confirm that therapy with SQV alone may not be effective, since trough levels are near the lower limit of antiretroviral efficacy. Although the combination of SQV with NLF results in higher SQV plasma concentrations in a bid regimen, in more than 60% of the patients SQV concentrations below IC 50 level were detected during the twelve-months study period. The combination of SQV with RTV yields the highest SQV-trough levels. SQV concentrations below the IC 50 were seen in only 31% of patients with the SQV/RTV combination. In conclusion, therapeutic drug monitoring allows an efficient surveillance of patients compliance. In addition, therapeutic drug monitoring represents a valuable tool for management of HAART in patients receiving a complex comedication or suffering from advanced liver disease.

Adult↗
PubMed2000

Phenotypic HIV-1 resistance correlates with treatment outcome of nelfinavir salvage therapy.

In order to analyse whether drug sensitivity testing would be beneficial for clinical decision-making in heavily pretreated patients, we retrospectively studied viral genotype and phenotypic drug resistance in 12 HIV-1-infected patients, each of them with a history of failing at least one therapeutic regimen including one or two protease inhibitors (PIs). The salvage therapy included nelfinavir as new PI in all cases. Four patients showed a sustained and five patients a transient viral load decrease. Three patients failed to show a significant decline of plasma HIV-1 RNA. In the baseline samples of these cases, resistance against all components of their combination therapy could be detected, whereas at least one antiretroviral drug was still active in the cases with transient treatment response. All patients with sustained therapy response harboured viruses that were either fully sensitive or resistant to only one of the drugs administered. In our study, phenotypic drug resistance was predictive for the success of antiretroviral salvage regimens.

Amino Acid Sequence↗
PubMed2001

Simultaneous determination of the new HIV protease inhibitor lopinavir (ABT 378) and of indinavir(1), amprenavir, saquinavir, ritonavir (ABT 538)(2) and nelfinavir(3) in human plasma by gradient HPLC.

Protease inhibitors are known by their inhibition of a viral protease that leads to production of immature and non-infectious virus particles. The novel protease inhibitor KALETRA is a co-formulation of lopinavir and ritonavir. Ritonavir reduces the metabolization of lopinavir by the cytochrome P450 3A4 isoenzyme which leads to markedly increased plasma levels of lopinavir(4). A new rapid and sensitive HPLC method for the simultaneous determination of lopinavir, indinavir, amprenavir, saquinavir, ritonavir and nelfinavir in human plasma has been developed. An aliquot of 500 microl plasma, spiked with internal standard, was extracted with 500 microl 0.1 M ammonium hydroxide solution and 5 ml tert. -butyl ether. After drying under a nitrogen stream, the residue was redissolved in an eluent consisting of 50 mM phosphate buffer, pH 5.40 and acetonitrile (50:50, v/v). Chromatographic separation was accomplished on a C-18 column using a non-linear gradient elution and ultraviolet detection at 215 nm.

Carbamates↗
PubMed2002

Effect of antiretroviral triple combinations including the protease inhibitor nelfinavir in heavily pretreated children with HIV-1 infection.

BACKGROUND: In this retrospective study the effect of antiretroviral triple therapy including the protease-inhibitor nelfinavir (NFV) on CD4-cells and viral load (VL) in heavily pretreated HIV-infected children was evaluated. PATIENTS AND METHODS: 20 children (<18 years) were included. Median duration of antiretroviral pretreatment was 27 months (range, 7 65), median initial VL was 4.7 log subset 10 (3.2 6.1) and median relative CD4-cells was 17.5% (3 33). Patients were put on combinations with NFV because of treatment failure (increasing VL), intolerance to prior therapy with PIs or adherence problems with prior indinavir. Viral load (RT-PCR, detection limit 50 copies/ml) and CD4-cells were measured every 4-8 weeks. RESULTS: Median viral load decreased 1.2 log(10) (-1.3 2.5), 0.9 log(10) (-0.8 - 2.5) and 0.4 log(10) (-0.5 - 3.0) after 12, 24 and 36 weeks. The VL of 2 patients was below the detection limit (50 copies/ml) after 24 weeks. The relative CD4-cell count increased from a median of 17.5% to 22%, 23% and 25% after 12, 24 and 36 weeks, respectively. Side effects of NFV were usually mild. WHO grade 1 or 2 diarrhea occurred in 70% and moderate elevations of triglycerides in 40% of the patients. At 48 weeks 18/20 patients had to be switched to other combinations due to virological failure. CONCLUSIONS: In children with intensive prior antiretroviral therapy combination therapy including NFV lead to a modest short-term reduction of the VL and increase in CD4-cells. However, the long-term antiretroviral effect was poor.

Adolescent↗
PubMed2002

The efficacy of combined zidovudine and lamivudine compared with that of combined zidovudine, lamivudine and nelfinavir in asymptomatic and early symptomatic HIV-infected children.

In this 6-month prospective study, we compared the efficacy of two treatment regimens: double-drug therapy with zidovudine (ZDV) and lamivudine (3TC) and triple-drug therapy with ZDV plus 3TC plus nelfinavir (NFV), in the treatment of asymptomatic and early symptomatic HIV-infected children. Twenty-five children were enrolled in this study and were divided into 2 groups: group A, consisting of 13 children who were given ZDV+3TC; group B, consisting of 12 children who were given ZDV+3TC+NFV. Serial determinations of weight, CD4-cell count, HIV RNA or plasma viral load (VL) and complete blood counts (CBC), liver function tests (LFT), blood urea nitrogen (BUN) tests, creatinine and serum amylase tests were performed at study entry and at 1, 3 and 6 months. The side-effects of drugs were recorded. Over the 6-month period, the median weight increase in group B (24%) was higher than in group A (2%). The median CD4-cell count increase from baseline in group B (94.5%) was better than in group A (9.4%). The reduction of VL below baseline in group B (1.2 log10; 20.8%) was also better than in group A (0.72 log10; 13.8%). However, these differences were not statistically significant (p>0.05). Both combination regimens could not completely suppress HIV RNA below detectable limits (<400 copies/ml). Both groups tolerated the regimens well; no side-effects or toxicities occurred. The efficacy levels of triple-drug therapy (ZDV+3TC+NFV) and double-drug therapy (ZDV+3TC) were not different. There were no side-effects and no deaths during the 6-month study period.

CD4 Lymphocyte Count↗
PubMedDate not supplied

A multicentre study to determine the efficacy and tolerability of a combination of nelfinavir (VIRACEPT), zalcitabine (HIVID) and zidovudine in the treatment of HIV infected Nigerian patients.

Summary Forty (40) HIV positive patients with CD4 cell counts between 100 - 500 cellh/mm3 were recruited from 8 different centres in Nigeria including a research centre and specialist and teaching hospitaLs They were enrolled into an open, non-comparative study of a triple combination regimen containing the Protease Inhibitor (PI), Nelfinavir and two Reverse Transcriptase Inhibitors (RTIs), Zakitabine (Hivid) and Zidovudine for a period of 24 weeks. Thirty-one (31) patients completed the study. Nine (9) patients withdrew from the study. Two of these because of Adverse Events (AE), 2 others because they developed tuberculosis and had to withdraw because of rifampicin therapy. The remaining five (5), withdrew voluntarily. Efficacy of the PI containing triple regimen was evaluated using viral load and absolute CD4 changes, weight gain and clinical response during the course of the triaL Twenty-two (22) patients had plasma viral loads measured at the beginning and at the end of the trial (24 weeks). Seventeen (17) out of the 22 patients (77%), experienced a significant reduction in their plasma viral loads (p<0.05 There was 1 log reduction in plasma viral load in 6 patients (25%), 2 log in 4 patients (17%). In 2 patients (8%), plasma viral load was reduced below the level of detection. The viral load increased over the treatment period in five patients (21%). Similarly 22 out of the 26 patients (85%) experienced increase in the level of their CD4 lymphocyte counts at the end of the study. The average CD4 counts of all 26 patients rose from 272.94 +/- 137.71/dl to 414 +/- 243.71/ul over 24 weeks (p<0.05). There was monthly rise of 27 CD4 cells/microl. Four (4) patients (15%) had a fall in their CD4 lymphocyte counts. Twenty (20) out of the 26 patients (77%), who completed the study were observed to have weight gains ranging from 1.5 to 31 kilograms over the 24 week study period. In 4 patients, there was no weight gain during the study period. Two patients (5%) were withdrawn due to adverse events from the viracept combination. One of these was because of life threatening diarrhoea while the other patient had severe peripheral neuropathy and severe weakness in the lower limbs. Eight (8) other patients had diarrhoea but not severe enough to stop them from continuing with the triaL Other adverse events seen include anaemia (1 patient), pancytopenia (1 patient), and transient elevation of serum urea and creatinine (1 patient). None of these adverse events was severe enough to warrant withdrawal from therapy. The study has therefore demonstrated the significant efficacy and tolerability of (Nelfinavir/Zalcitabine/ Zidovudine combination in suppressing viral replication, increasing the CD4 cell counts and improving the quality of life in Nigeria patients with HIV.

Anti-HIV Agents↗
PubMed2002

Evolution of antiretroviral phenotypic and genotypic drug resistance in antiretroviral-naive HIV-1-infected children treated with abacavir/lamivudine, zidovudine/lamivudine or abacavir/zidovudine, with or without nelfinavir (the PENTA 5 trial).

PURPOSE AND METHODS: To describe the evolution of resistance to zidovudine (ZDV), lamivudine (3TC), abacavir (ABC) and nelfinavir (NFV), 113 previously untreated children in the PENTA 5 trial had resistance assayed at baseline, rebound and/or 24, 48, 72 weeks (VIRCO: phenotyping and genotyping with 'Virtual Phenotype' interpretation). RESULTS: At baseline, few reverse transcriptase mutations and no primary protease inhibitor mutations were observed. Time to detectable HIV-1 RNA with reduced phenotypic susceptibility to any drug was shortest in the ZDV+3TC arm (overall logrank P=0.02). Through a median follow-up of 55 weeks, at their last assessment 11 (28%), 16 (40%) and 13 (32%) children with detectable HIV-1 RNA and a resistance test available had mutations conferring resistance to none, one, or two or more trial drugs, respectively, according to the virtual phenotype. Reduced phenotypic susceptibility to ABC only occurred in the 3TC+ABC arm and required K65R and/or L74V in addition to M184V. NFV-resistant virus was selected slowly through D30N or L90M pathways, and selection of ZDV-resistant virus was rare. CONCLUSIONS: Selection of 3TC-resistant virus was most frequent, followed by NFV and/or ABC; selection of ZDV-resistant virus was rare. Importantly, although in vitro, ABC selects for M184V as the first mutation, ABC did not select for M184V when combined with ZDV without 3TC. The most sustained HIV-1 RNA response was in the 3TC+ABC arm, but mutations conferring reduced susceptibility to 3TC and/or ABC evolved more frequently if virological failure occurred with 3TC+ABC than with ZDV+ABC.

Acquired Immunodeficiency Syndrome↗
PubMed2003

Long-term efficacy and safety of twice-daily saquinavir soft gelatin capsules (SGC), with or without nelfinavir, and three times daily saquinavir-SGC, in triple combination therapy for HIV infection: 100-week follow-up.

OBJECTIVES: To evaluate the long-term efficacy and safety of saquinavir soft gelatin capsules (SQV-SGC) (Fortovase) in twice-daily, with or without nelfinavir (NFV), and three-times-daily regimens. This was an extension of a 48-week study, with follow-up to 100 weeks. DESIGN: Patients were randomized to one of three treatment arms: arm A, SQV-SGC 1200 mg three times daily plus two nucleoside reverse transcriptase inhibitors (NRTIs); arm B, SQV-SGC 1,600 mg twice daily plus two NRTIs; or arm C, SQV-SGC 1200 mg twice daily plus NFV 1250 mg twice daily plus one NRTI. At week 48, patients could either withdraw or continue in the study to the common study closure date. Antiretroviral activity was assessed by changes in HIV-1 RNA values and CD4 cell counts from 48 weeks until 100 weeks. RESULTS: In the modified intention-to-treat population, the proportion of patients with HIV-1 RNA values <400 copies/ml was statistically different between arms A and C (49 vs 28%, P=0.017), and arms B and C (48 vs 28%, P=0.027). Continued suppression of HIV-1 replication (HIV-1 RNA <400 copies/ml) was observed through 100 weeks in 83% (30/36), 73% (29/40) and 62% (16/26) of patients in treatment arms A, B and C, respectively, in the on-treatment (OT) population. At 100 weeks, sustained increases were achieved in mean CD4 cell counts of +361, +273 and +309 cells/mm3, respectively (OT population). No additional adverse events or increase in the proportion of patients reporting adverse events were observed from 48 weeks to 100 weeks. CONCLUSIONS: This study demonstrates the long-term efficacy and safety of SQV-SGC twice daily, with or without NFV, and three times daily, in triple combination therapy for HIV-1-infected patients. However, the evidence suggests that long-term treatment with SQV-SGC plus NFV may be less acceptable to patients.

Anti-HIV Agents↗
PubMed2000

Nelfinavir potency concerns.

Results from several recent studies may help clarify how to best use anti-HIV drugs as part of first line therapy. These results seem to suggest that nelfinavir (Viracept), the most widely used protease inhibitor, may not be as potent as other drugs in its class or some of the non-nucleoside RT inhibitors (NNRTIs). This article provides an overview of the studies.

Clinical Trials as Topic↗
PubMed2004

Immune restoration in HIV-positive, antiretroviral-naive patients after 1 year of zidovudine/lamivudine plus nelfinavir or nevirapine.

OBJECTIVES: To evaluate the immunological response in HIV-1-infected, antiretroviral-naive patients receiving highly active antiretroviral therapy regimen of two nucleosides plus a protease inhibitor or a non-nucleoside reverse transcriptase inhibitor. DESIGN AND METHODS: Of 142 patients included in a randomized, open, multicentre trial comparing zidovudine/lamivudine plus nelfinavir (NFV) or nevirapine (NVP), 36 patients (16 NFV, 20 NVP) were enrolled in an immunological substudy. Mean baseline CD4 T-cell counts was 360/mm3 (range: 11-679) and mean baseline plasma viral load >50000 copies/ml (range: 2240-1468210). Viral load (VL), T-cell subsets and T-cell functions were analysed at baseline and after 1 year of treatment. RESULTS: After 12 months of follow-up, plasma viral load was reduced similarly in both groups, with 78% (NFV) and 83% (NVP) of patients achieving a VL <200 copies/ml. A significant increase in CD4 T cells was observed in both groups (mean: +182 cells, P=0.001). Both regimens were similarly effective in reducing activated T cells (CD38 and DR). A significant increase of both CD4 and CD8 CD28 T cells occurred in both arms of treatment. Patients of both regimens showed a significant decrease of activated memory (CD45RA-CD45RO+) CD8 T cells and a clear increase of naive (CD45RA+CD45RO-) CD8 T cells. Peripheral blood mononuclear cell proliferative responses to polyclonal stimuli (CD3 and CD3 +CD28) as well as to ubiquitous cytomegalovirus antigen increased significantly in both groups after 12 months of follow-up. Nevertheless, neither at baseline nor after 1 year of treatment, these patients showed any significant T-cell responsiveness to HIV-1 recombinant proteins gp160 or p24. CONCLUSIONS: Our data indicate that immune restoration achieved after 1 year of therapy with either NFV or NVP was similar. This reinforces the role of NVP-containing regimens as a valid option for initiating antiretroviral therapy. Nevertheless, additional therapeutic approaches should be envisaged to restore HIV-1-specific T-cell responses.

Adult↗
PubMed2004

Influence of single-nucleotide polymorphisms in the multidrug resistance-1 gene on the cellular export of nelfinavir and its clinical implication for highly active antiretroviral therapy.

Protease inhibitors (PIs) such as nelfinavir (NFV) suppress HIV replication. PIs are substrates of P-glycoprotein (P-gp), the product of the multidrug-resistance-1 (MDR1) gene. Three single-nucleotide polymorphisms (SNPs) are present in exons of the MDR1 gene: MDR1 1236, MDR1 2677 and MDR1 3435. We speculated that these genetic polymorphisms affected PI concentration in the cell. To verify this hypothesis, we first genotyped these SNPs in 79 Japanese patients by the SNaPshot method and found incomplete linkage disequilibrium between the SNPs. Because the SNP at MDR1 3435 has been reported to be associated with P-gp expression, we evaluated the effect of that SNP on the export of NFV from HIV-positive patients' lymphoblastoid cell lines by measuring time-dependent decrease in the amount of intracellular NFV by high-performance liquid chromatography. We found the intracellular concentration of NFV in lymphoblastoid cell lines (LCLs) with the homozygous T/T genotype at MDR1 3435 were higher than that with C/C genotype with statistical significance. This suggests that the activity of P-gp in patients' LCL cells with the MDR1 3435 T/T genotype was lower. In a retrospective study we evaluated the effect of the SNPs on CD4 cell count recovery in response to antiretroviral treatment with PIs, and obtained statistically significant evidence that suggested marginal association of the SNP at MDR1 1236 but not at MDR1 2677 or MDR1 3435. As in vitro results were not consistent with the clinical evaluation, clinical importance of MDR1 genotyping for antiretroviral therapy remains to be investigated in a larger, case-controlled study.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed2005

The HIV protease inhibitors saquinavir, ritonavir, and nelfinavir induce apoptosis and decrease barrier function in human intestinal epithelial cells.

BACKGROUND AND AIMS: Diarrhoea is a frequent adverse effect of HIV protease inhibitors (PIs) which may be due to intestinal barrier disruption. We investigated whether tight junction dysregulation, apoptosis or necrosis are responsible for this epithelial damage. METHODS: Saquinavir, nelfinavir, and ritonavir were added to the mucosal or serosal side of HT-29/B6 colon cell monolayers. Transepithelial resistance was monitored for 72 h to assess epithelial barrier function. Apoptosis and necrosis were investigated by light and electron microscopy and quantified by nucleosome ELISA and LDH measurement, respectively. Tight junction components were analysed by Western blots of occludin and zonula occludens. Apoptosis induction in normal human intestinal epithelium was examined by measurement of poly(ADP-ribose) polymerase (PARP) cleavage in Western blots of mucosal tissue explants cultured with PIs for 24 h. RESULTS: HIV PIs decreased transepithelial resistance by more than 44% in HT-29/B6 monolayers. Histology revealed massive apoptotic body formation but no evidence for necrosis after PI treatment. Correspondingly, LDH release was lower than 0.2%/h of total LDH, independent of PI treatment, and nucleosomes were increased up to 22-fold after drug treatment versus control. Occludin and zonula occludens-1 expression in the membrane were not diminished. PARP cleavage increased in normal human intestinal tissue treated with PIs. CONCLUSIONS: PI-induced barrier disruption in intestinal epithelial cells is not due to necrosis or tight junction alterations, but to induction of massive apoptosis which may lead to leak-flux diarrhoea in vivo. Our findings suggest that induction of apoptosis by PIs could have potential for antitumour therapy.

Adult↗
PubMed2005

In vivo effects of highly active antiretroviral therapies containing the protease inhibitor nelfinavir on mitochondrially driven apoptosis.

BACKGROUND: In vitro studies have reported controversial effects of protease inhibitors (PIs) on mitochondrially driven apoptosis. Additionally, since PIs in the clinical setting are almost always given in combination with nucleoside analogues, which may have negative effects on mitochondrial DNA (mtDNA), the impact of PI-containing highly active antiretroviral therapy (HAART) on apoptosis and mtDNA content is unclear. PATIENTS AND METHODS: A cross-sectional study was performed including 20 HIV-negative (HIV-) patients, 16 HIV-positive, antiretroviral-naive (HIV+) patients and 17 HIV-positive patients receiving the PI nelfinavir (NFV) plus zidovudine and lamivudine (AZT+3TC) or didanosine and stavudine (ddl+d4T)--collectively known as HIV+PI--as first-line antiretroviral treatment for at least 12 months. Peripheral blood mononuclear cells (PBMCs) were isolated. BCL2 expression (anti-apoptotic) and the levels of the cleaved, active form of caspase-9 (pro-apoptotic) were determined by western blot. An index of mitochondrially driven apoptotic activation was estimated calculating the ratio caspase-9:BCL2. Mitochorldrial DNA content was measured by real-time PCR. RESULTS: BCL2 expression was lower in HIV+ than in HIV-patients (P < 0.01), whereas levels of caspase-9 were higher (P = 0.001). The caspase-9:BCL2 ratio was significantly increased in HIV+ compared with HIV-individuals (P < 0.001). Mitochondrial DNA content was also decreased in HIV+ compared with HIV-patients (P < 0.001). The HIV+PI group exhibited a trend to normalization for BCL2 expression and caspase-9 compared with the HIV+ group, whereas the caspase-9:BCL2 ratio significantly improved (decreased, P < 0.05 compared with HIV+ group). The mtDNA content in the HIV+PI group was similar to that of the HIV+ group, although the results of mtDNA content differed depending on whether NFV was combined with AZT+3TC (preserved) or with ddl+d4T (depleted). Conversely, no differences were found in apoptotic markers between the two subgroups of HIV+PI. CONCLUSIONS: NFV-based PI-containing HAART regimens may exert some beneficial effects counteracting the increased mitochondrially driven apoptosis present in HIV-infected people.

Adult↗
PubMed2004

Determination of atazanavir and other antiretroviral drugs (indinavir, amprenavir, nelfinavir and its active metabolite M8, saquinavir, ritonavir, lopinavir, nevirapine and efavirenz) plasma levels by high performance liquid chromatography with UV detection.

A global method is proposed for therapeutic drug monitoring of atazanavir, a novel protease inhibitor and of all other protease inhibitors (PI) and non nucleoside reverse transcriptase inhibitors (NNRTI) which are currently used to treat HIV patients. All drugs are extracted after a liquid-liquid extraction and separated on a C18 column with a binary gradient elution except lopinavir which is separated without this gradient. The absorbance is measured at 259 nm except for lopinavir (205 nm) and nevirapine (320 nm). This method is specific, accurate, precise (the intra-day and inter-day imprecision and inaccuracy are lower than 15%) and the limits of quantitation (0.40 mg/L for nevirapine, 0.10 mg/L for indinavir, 0.10 mg/l for M8, 0.05 mg/L for amprenavir, 0.10 mg/L for nelfinavir, 0.10 mg/L for saquinavir, 0.10 mg/L for ritonavir, 0.10 mg/L for efavirenz, 0.10 mg/L for atazanavir and 0.20 mg/L for lopinavir) are consistent with trough plasma concentrations allowing to use this method for therapeutic drug monitoring of PI and NNRTI.

Atazanavir Sulfate↗
PubMed2005

Intracellular measurements of anti-HIV drugs indinavir, amprenavir, saquinavir, ritonavir, nelfinavir, lopinavir, atazanavir, efavirenz and nevirapine in peripheral blood mononuclear cells by liquid chromatography coupled to tandem mass spectrometry.

A sensitive and accurate liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for the intracellular determination of nine antiretroviral drugs in human peripheral blood mononuclear cells (PBMCs) is proposed. PBMCs are isolated by density gradient centrifugation using Vacutainer CPT tubes and cell count is performed with a Coulter instrument. Single-step extraction of drugs from PBMCs pellets is performed with MeOH 50% (with clozapine added as internal standard, I.S.) and the supernatant is injected onto a 2.1 mm x 30 mm SymmetryShield 3.5 microm-RP18 column equipped with a 2.1 x 10 mm guard column. Chromatographic separations are performed using a gradient program with a mixture of 2 mM ammonium acetate containing 0.1% formic acid and acetonitrile with 0.1% formic acid. Analytes quantification is performed by electro-spray ionisation-triple quadrupole mass spectrometry using the selected reaction monitoring (SRM) detection mode. The positive mode is used for the HIV protease inhibitors (PIs) indinavir, amprenavir, saquinavir, ritonavir, nelfinavir, lopinavir, atazanavir and the non-nucleoside reverse transcriptase inhibitors (NNRTIs) nevirapine, and the negative mode is applied for efavirenz. The calibration curves are prepared using blank PBMCs spiked with antiretroviral drugs at concentrations ranging from 0.5 to 100 ng/ml of cell extracts and fitted to a quadratic regression model weighted by 1/(concentration)(2). The lower limit of quantification is less than 0.5 ng/ml. The mean extraction recovery for all PIs/NNRTIs is always above 88%. The method is precise, with mean inter-day CV% within 0.6-10.2%, and accurate (range of inter-day deviation from nominal values -7.2 to +8.3%). This analytical method can be conveniently used in clinical research for the assessment of intracellular levels of all PIs/NNRTIs commercially available at present using a simple one-step cell extraction of PBMCs followed by liquid chromatography coupled with tandem triple quadripole mass detection.

Calibration↗
PubMed2005

Simultaneous determination of HIV protease inhibitors amprenavir, atazanavir, indinavir, lopinavir, nelfinavir, ritonavir and saquinavir in human plasma by high-performance liquid chromatography-tandem mass spectrometry.

We report a precise and accurate method for simultaneous quantification of protease inhibitors (PIs) amprenavir, atazanavir, indinavir, lopinavir, nelfinavir, ritonavir and saquinavir in plasma. An internal standard was added to samples prior to protein precipitation with acetonitrile followed by addition of ammonium formate buffer. Analysis was by HPLC-MS/MS. Calibration curves were validated over concentration ranges encompassing both subtherapeutic and potentially 'toxic' drug concentrations. Inter- and intra-assay variation were below 11% and PI recovery was above 87%. The bioanalytical method described is successfully applied to measure PI concentrations obtained from clinical pharmacokinetic studies and routine therapeutic drug monitoring (TDM).

Calibration↗