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Response to first protease inhibitor- and efavirenz-containing antiretroviral combination therapy. The Swiss HIV Cohort Study.

OBJECTIVE: To compare the response to protease inhibitor (PI) and efavirenz-containing combination therapy among treatment-naive HIV-infected persons. DESIGN: Prospective observational cohort study. METHODS: Response to treatment was analysed according to the intent-to-treat principle among antiretroviral-naive patients who started either efavirenz (n = 89) or PI (n = 183) plus two nucleoside reverse transcriptase inhibitors between February 1999 and March 2000 using Kaplan-Meier and multivariable Cox proportional hazard regression methods. Primary endpoint was time to undetectable plasma viral load. Secondary endpoints included the number of CD4 cells gained, virological rebound, treatment change, and clinical progression. RESULTS: Patients on PI regimens had lower median CD4 counts (165 versus 216 x 5 106/l; P = 0.15) and were more likely to have AIDS at initiation of treatment (25% versus 15% P = 0.048) than patients starting efavirenz regimens. The probability of reaching plasma HIV-1 RNA < 400 copies/ml was higher with efavirenz- than with PI-containing regimens [adjusted hazard ratio, 1.75; 95% confidence interval (CI), 1.34-2.29]. Median times to undetectable viral load were 58 days (95% CI, 44-70 days) for efavirenz-treated and 88 days (95% CI, 79-98 days) for PI-treated patients. The median number of CD4 cells gained in the first 6 months (90 x 10(6) cells/l with efavirenz, 10(7) x 10(6) cells/l with PI; P = 0.63), time to and reasons for treatment change, time to viral rebound, drug intolerance and clinical progression rates were similar in the two treatment groups. CONCLUSIONS: Treatment with efavirenz-, compared with PI-based regimens, appeared to result in a superior virological response but no difference in immunological or clinical efficacy. The relevance of these observations remains to be determined in studies with longer follow-up.

Adult↗

Comparison of two antiretroviral triple combinations including the protease inhibitor indinavir in children infected with human immunodeficiency virus.

OBJECTIVE: The effects of two antiretroviral triple combinations including the protease inhibitor indinavir on the surrogate markers, viral load and CD4 cells were evaluated. METHODS: Fifteen patients with high viral load or disease progression under their prior antiretroviral therapy were switched to zidovudine/lamivudine/indinavir (Group A, n = 10) or stavudine/lamivudine/indinavir (Group B, n = 5). Serial determinations of viral load and CD4 cells were performed. RESULTS: The median reduction of the viral load was 0.6 log after 3 months and 0.8 log after 6 months in Group A and 2.5 and 2.4 log after 3 and 6 months in Group B, respectively. After 3 and 6 months 3 of 10 patients in Group A and 3 of 5 patients in Group B had viral load reductions below the detection limit of the assay. Patients with an additional switch of nucleoside analogues at start of indinavir therapy (regardless of the specific reverse transcriptase inhibitor used) had significantly better reductions of the viral load than patients without such a switch (median 2.3 log vs. 0.2 log after 6 months, P < 0.05). In Group A the median of the relative increase of CD4 cells was 37% after 3 months and 57% after 6 months (P = 0.002); in Group B the medians of the relative increase of CD4 cells were 145 and 163% (not significant), respectively. Two patients from Group A and 1 from Group B developed renal calculi, which resolved after adequate hydration. One patient was withdrawn because of intractable vomiting attributed to indinavir. CONCLUSION: In a small cohort of HIV-infected pediatric patients with extensive prior antiretroviral treatment, triple therapy including indinavir had a sustained effect on the decrease of the viral load and the increase of CD4 cells similar to results obtained in antiretrovirally experienced adults. This effect was significantly better in patients with an additional switch of a nucleoside analogue at start of triple therapy with indinavir than in patients without such a change.

Adolescent↗

Advances in understanding drug-induced neuropathies.

Many commonly used medications have neurotoxic adverse effects; the most common of these is peripheral neuropathy. Neuropathy can be a dose-limiting adverse effect for many medications used in life-threatening conditions, such as malignancy and HIV-related disease. Epidemiological evidence supports previous case reports of HMG-CoA reductase inhibitors (or 'statins') causing an axonal sensorimotor neuropathy or a purely small-fibre neuropathy in some patients. The neuropathy improves when the medication is withdrawn. Despite the association between HMG-CoA reductase inhibitors and neuropathy, the risk is low compared with the significant vascular protective benefits. Oxaliplatin, a new platinum chemotherapy agent designed to have fewer adverse effects than other such agents, has been shown to cause a transient initial dysaesthesia in addition to an axonal polyneuropathy. Thalidomide, an old therapy currently being utilised for new therapeutic indications (e.g. treatment of haematological malignancies), is associated with a painful, axonal sensorimotor neuropathy that does not improve on withdrawal of the drug. Nucleoside reverse transcriptase inhibitors are important components of highly active antiretroviral therapy, but are associated with a sensory neuropathy that is likely to be due to a direct effect of these drugs on mitochondrial DNA replication. New research demonstrates that lactate levels may help discriminate between neuropathy caused by nucleoside analogues and HIV-induced neuropathy. Understanding the mechanism of drug-induced neuropathy has led to advances in preventing this disabling condition.

Antineoplastic Agents↗

Acquired immunodeficiency syndrome-related Kaposi's sarcoma regression after highly active antiretroviral therapy: biologic correlates of clinical outcome.

BACKGROUND: Kaposi's sarcoma (KS) is the most common cancer seen in subjects with acquired immunodeficiency syndrome (AIDS). KS etiology and pathogenesis are still ill defined, and no definite improvement in survival has been obtained with current chemotherapeutic regimens. This open prospective study was aimed at evaluating the clinical response of AIDS-related KS to highly active antiretroviral therapy (HAART), a combination of protease and reverse transcriptase inhibitors, as well as the relationship between clinical response, human immunodeficiency virus type 1 (HIV-1) burden, and antibody titer against human herpesvirus 8 (HHV8) proteins. PATIENTS AND METHODS: Fourteen KS patients were studied; 12 were in the poor-risk group. At given intervals, the patients underwent clinical examination, and their CD4(+) cell counts, plasma HIV-1 RNA levels, and antibody titers to lytic-phase ORF65 and latent-phase HHV8 proteins were determined. RESULTS: When last seen, the overall clinical response rate was 86% (median follow-up, 22 months); 10 complete and two partial responses were achieved, and two patients showed disease progression. All patients with complete or partial response showed a consistent decrease in HIV-1 RNA levels, with a corresponding increase in CD4(+) cell counts; HIV-1 RNA levels in the two progressors remained persistently high, despite a change in HAART. HHV8 ORF65 antibody titers were generally higher in patients with extensive skin or mucosal/visceral involvement versus patients with limited disease; no differences in latent-phase HHV8 antibody titers were observed in relation to tumor burden. CONCLUSION: The findings indicate that antiretroviral therapy with protease inhibitors is effective for AIDS-related KS; the clinical response was correlated with a decrease in plasma HIV-1 RNA levels and an increase in CD4(+) lymphocytes, whereas antibody levels to the lytic-phase HHV8 protein were influenced by the extent of tumor involvement.

Acquired Immunodeficiency Syndrome↗

Tests on new NNRTI show strong potency.

Early clinical studies of TMC125, a new non-nucleoside reverse transcriptase inhibitor, indicate the drug is extremely potent, with an average reduction in HIV viral load of 99% after one week of treatment.

Anti-HIV Agents↗

Spectrum of antiviral activity of o-(acetoxyphenyl)hept-2-ynyl sulphide (APHS).

Since some antiviral drugs have a broad spectrum of action, the aim of this study was to assess whether o-(acetoxyphenyl)hept-2-ynyl sulphide (APHS), a recently described inhibitor of human immunodeficiency virus type 1 (HIV-1) replication, has an effect on the replication of other retroviruses, (-) and (+) RNA viruses and DNA viruses. APHS did not affect the replication of feline immunodeficiency virus, HIV-2 and a HIV-1 strain resistant to non-nucleoside reverse transcriptase inhibitors (NNRTI). APHS could also not inhibit the replication of the RNA viruses, respiratory syncytium virus or mouse hepatitis virus. In contrast, APHS did inhibit the replication of wild-type herpes simplex virus type 1 (HSV-1) as well as acyclovir-resistant HSV-1 and HSV-2 mutant. These results suggest that APHS is a NNRTI of HIV-1 replication, but not HIV-2 replication, and that APHS is an inhibitor of both HSV-1 and HSV-2 replication.

Acyclovir↗

Different immunologic profiles characterize HIV infection in highly active antiretroviral therapy-treated and antiretroviral-naïve patients with undetectable viraemia. The Master Group.

BACKGROUND: Suppression of human immunodeficiency virus (HIV) replication can be obtained in chronically infected individuals by highly active antiretroviral therapy (HAART) and can also be observed in antiretroviral-naïve patients. The immunological correlates of these two situations were examined. DESIGN AND METHODS: Cross-sectional study involving 32 HIV-infected patients with undetectable HIV plasma viraemia (< 500 copies/ml) and either antiretroviral-naive (n = 14) or undergoing HAART therapy with two nucleoside reverse transcriptase inhibitors (NRTI) plus one (n = 13) or two (n = 5) protease inhibitors (PI). CD4 counts, disease duration, and CDC clinical stage were comparable between the two groups of individuals. Immune parameters (antigen- and mitogen-stimulated proliferation and cytokine production; cytokine mRNA; beta chemokine production; HIV coreceptors mRNA) were analysed in all patients. RESULTS: Results showed immune profiles to be profoundly different in antiretroviral-naive in comparison with HAART-treated patients. Thus: (1) T-cell proliferation to HIV-specific and HIV-unrelated antigens is potent in antiretroviral-naive but suppressed in HAART-treated individuals; (2) interleukin-(IL)2, IL-12 and interferon gamma (IFNgamma) production is robust in naive patients; and (3) a high CCR5/low CXCR4 pattern of HIV coreceptors-specific mRNA is observed in naive but not in HAART-treated patients. In contrast with these observations, no clear differences were detected when beta chemokine production by either peripheral blood mononuclear cells or purified CD8+ T-cells was analysed. Results from HAART-treated patients undergoing therapy with one PI and two NRTI or two PI and two NRTI were in very close agreement. CONCLUSIONS: These data suggest that control over HIV replication can be independently achieved by pharmacological or immunologic means. HAART is associated with weaker HIV-specific and -non-specific immune responses.

CD8-Positive T-Lymphocytes↗

Drug treatment for HIV-1-associated dementia.

The manifestation of HIV-1-associated minor motor deficits or HIV-1-associated dementia indicates viral activity within the CNS. Highly active antiretroviral therapy (HAART) has a prophylactic effect, which does not protect all patients, because different pathomechanisms are involved. A CNS-specific therapeutic efficacy can be demonstrated for nucleoside and non-nucleoside reverse transcriptase inhibitors (NRTIs; NNRTIs). To be effective in the CNS, HAART should contain either zidovudine or stavudine and NNRTI should be added if there is dinical or preclinical evidence of CNS involvement. Protease inhibitors may be sufficient to lower high systemic viral burden and thus protect the CNS from HIV-1 invasion.

AIDS Dementia Complex↗

First synthesis and evaluation of the inhibitory effects of aza analogues of TSAO on HIV-1 replication.

Aza TSAO-T derivatives bearing a dihydroisothiazole dioxide ring instead of an oxathiole dioxide ring at the C-3' position on the sugar moiety were prepared. We have synthesized four families of compounds depending on substitution at both N-3 and N-2' '. Biological evaluation showed that these compounds are HIV-1(III(B))-specific and potent reverse transcriptase inhibitors with EC(50) values between 0.13 and 3.5 microM in cell culture.

Aza Compounds↗

Early virological failure in treatment-naive HIV-infected adults receiving didanosine and tenofovir plus efavirenz or nevirapine.

A 50% rate of early virological failure associated with the selection of resistance mutations was seen in a group of 14 antiretroviral-naive adults who initiated highly active antiretroviral therapy with tenofovir and didanosine plus efavirenz or nevirapine. At month 6, the mutations detected were K65R, L74V, L100I, K103N/R/T, Y181C and G190E/Q/S. These results argue against the use of tenofovir plus didanosine in HIV-infected antiretroviral-naive adults even when the third drug is a non-nucleoside reverse transcriptase inhibitor.

Adenine↗

Contraindicated antiretroviral drug combinations.

The proper implementation of combination antiretroviral treatment regimens is fundamental to successful therapeutic outcomes for patients with HIV/AIDS. Unfortunately, some patients are still being prescribed contraindicated antiretroviral regimens that include: 1. stavudine plus zidovudine; 2. Invirase plus two nucleoside analog reverse transcriptase inhibitors (NRTIS); 3. zalcitabine plus didanosine; 4. zalcitabine plus stavudine; and, 5. zalcitabine plus lamivudine. Inappropriate regimens such as these either have limited effectiveness or potential severe toxicity.

Anti-Retroviral Agents↗

Virologic and immunologic response to a boosted double-protease inhibitor-based therapy in highly pretreated HIV-1-infected patients.

PURPOSE: To assess the virologic and immunologic response to a boosted double-protease inhibitor (PI) regimen of highly pretreated patients infected with HIV-1 and to examine the role of PI resistance and concentration of serum saquinavir. METHOD: In an open-label prospective study, lopinavir/ritonavir, saquinavir-sgc, lamivudine, and other nucleoside analogues were offered to highly pretreated patients who had advanced HIV-1 infection and who had failed at least 2 previous highly active antiretroviral therapy regimens including at least 1 nonnucleoside reverse transcriptase inhibitor. The relationship between baseline drug resistance and steady-state saquinavir serum levels and early (week 4) and sustained (week 48) virologic response was documented. RESULTS: 35 advanced HIV-1 patients were enrolled. The boosted double-PI regimen was well tolerated. Twenty-two (63%) of the 35 patients had a > 0.8 log(10) decrease in HIV viral load at week 4. After 48 weeks of follow-up, the 22 patients who remained on the study therapy had an average decrease in viral load of 1 log(10) and had a median increase in CD4 cells of 60 cell/microL. Multiple logistic regression analysis indicated that genotypic resistance to both PIs and the week-3 trough concentrations of saquinavir were associated with virologic outcome at week 4. The presence of > or = 6 lopinavir mutations [odds ratio (OR) 0.03; 95% CI 0.01 to 0.79] and the 48V mutation (OR 0.01; 95%CI <0.01 to 0.88) was independently associated with lower odds of achieving an early response, whereas a higher saquinavir concentration at week 3 (OR 8.36; 95% CI 1.28 to 54.70) was associated with greater odds of an early response. CONCLUSION: These findings suggest that baseline PI resistance and saquinavir concentration were associated with virologic response and should be considered when planning salvage therapy.

Adult↗

Metabolic benefits 24 months after replacing a protease inhibitor with abacavir, efavirenz or nevirapine.

OBJECTIVE: To evaluate the 24-month metabolic and morphological benefits obtained from replacing the protease inhibitor (PI) in a regimen with nevirapine, efavirenz or abacavir. DESIGN AND METHODS: NEFA was a randomized study designed to compare the efficacy of nevirapine, efavirenz or abacavir as substitutes for PI. A subset of 90 patients [abacavir (n = 29), efavirenz (n = 32), nevirapine (n = 29)] formed the metabolic study. Fasting total cholesterol (TC), high density lipoprotein cholesterol (HDL-c) and triglycerides levels were determined. Glucose homeostasis parameters were also collected. Lipodystrophy was evaluated by clinical examination and morphological measurements. RESULTS: Treatment simplification led to overall lipid profile improvements. At 24 months, the two non-nucleoside reverse transcriptase inhibitors produced similar lipid benefits: HDL-c levels increased [efavirenz, 15% (P = 0.001); nevirapine, 21% (P < 0.001)] and TC to HDL-c ratios decreased [efavirenz, 14% (P < 0.001); nevirapine, 19% (P < 0.01)], an effect not observed in the abacavir arm. Non-HDL-c levels decreased by 10% in both the abacavir (P = 0.001) and efavirenz (P < 0.05) arms. Significant decreases in the levels of triglycerides occurred for the first year in all treatments; however, at 24 months most of the initial loss had been regained. Patients with baseline moderate or severe lipodystrophy obtained less-pronounced lipid benefits. Several insulin resistance markers showed a trend towards improvement. Conversely, no improvements in morphological abnormalities were observed. CONCLUSIONS: Replacing PI with efavirenz, nevirapine or abacavir improved the lipid profile, with more marked results in non-lipodystrophic patients. In contrast, this strategy does not seem to be effective for reversing body fat abnormalities.

Adult↗

Thiourea-based non-nucleoside inhibitors of HIV reverse transcriptase as bifunctional organocatalysts in the asymmetric Strecker synthesis.

The potential of novel and known pyridyl thiourea derivatives (non-nucleoside inhibitors (NNI) of HIV reverse transcriptase) as bifunctional organic catalysts in the asymmetric Strecker synthesis was investigated. It was shown that incorporation of the imidazolyl moiety in place of a pyridyl group results in a new thiourea derivative that displays a much higher catalytic activity.

Catalysis↗

[Fatty liver and increased serum lactate in a woman with HIV].

HISTORY AND CLINICAL PRESENTATION: A 50-year-old woman with HIV who had undergone a 7-month course of antiretroviral treatment (stavudine, lamivudine, indinavir, ritonavir) was admitted to hospital with abdominal pain, nausea, vomiting and muscle pain. Physical examination revealed subfebrile body temperature and hepatomegaly. INVESTIGATIONS: Biochemical tests revealed moderate elevations of gamma GT, AST and ALT as well as marked hyperlactatemia. Abdominal computed tomography indicated pronounced hepatomegaly. Percutaneous liver biopsy was performed and demonstrated macro- and microvesicular hepatic steatosis on light microscopy. Electron microscopy showed mitochondrial damage. TREATMENT AND COURSE: Despite discontinuation of antiretroviral treatment serum lactate levels further increased initially and clinical symptoms were progressive. In the following weeks, a slow but steady recovery of laboratory values and physical condition was noted. CONCLUSION: Hyperlactataemia associated with abdominal pain can indicate the mitochondrial toxicity due to nucleoside reverse transcriptase inhibitors. After drug discontinuation, improvement of clinical symptoms and laboratory values is often delayed, frequently for several weeks.

Abdominal Pain↗

Discordant Human Immunodeficiency Virus Type 1 drug resistance mutations, including K103N, observed in cerebrospinal fluid and plasma.

Discordant resistance mutations were seen in human immunodeficiency virus type 1 (HIV-1) isolated from specimens of blood and cerebrospinal fluid (CSF) obtained from 3 of 6 patients. To our knowledge, this is the first report of HIV-1 isolated from CSF harboring the K103N mutation, which confers resistance to the nonnucleoside reverse-transcriptase inhibitors, and this finding may indicate that virus in the CSF replicates independently from virus in the blood compartment.

Amino Acid Substitution↗

Intracellular and plasma pharmacokinetics of nelfinavir and M8 in HIV-infected patients: relationship with P-glycoprotein expression.

One of the targets of antiretroviral therapy is within cells infected with HIV. In order to improve therapeutic efficacy, it is therefore important that the intracellular pharmacokinetics of drugs, such as nelfinavir mesylate and its active metabolite M8, are studied in addition to plasma pharmacokinetics. Previously, the intracellular accumulation of protease inhibitors has been reported in vivo, displaying the following hierarchy: nelfinavir > saquinavir > ritonavir > indinavir. Multidrug resistance transporters, such as P-glycoprotein (P-gp), may result in a lower intracellular concentration of drug via an efflux mechanism, thus contributing to sanctuary site formation. The objective of this study was to determine concentrations of nelfinavir and M8 in plasma and peripheral blood mononuclear cells from HIV-infected patients, and to ascertain the relationship between intracellular accumulation and lymphocyte P-gp expression. Venous blood samples from 12 HIV-infected patients (viral load <50 copies/ml) receiving nelfinavir (1250 mg twice daily) and dual nucleoside reverse transcriptase inhibitor therapy were collected over a full dosage interval (0, 2, 4, 8 and 12 h). Plasma and intracellular (cell-associated) drug concentrations were measured by HPLC-MS/MS. Drug exposure in plasma and cells was expressed as the area under the concentration-time curve (AUC(0-12h)), derived from non-compartmental modelling. The ratio of intracellular AUC(0-12h)/total plasma AUC(0-12h) was calculated to determine cellular drug accumulation. P-gp expression on lymphocytes was determined by flow cytometry. The median (range) AUC(0-12h) of nelfinavir in plasma and cellular compartments was 21.8 mg x h x l(-1) (5.64-50.8) and 104.6 mg x h x l(-1) (23.1-265.7), respectively. Corresponding values for M8 in plasma and cells were 6.60 mg x h x l(-1) (2.16-17.3) and 19.6 mg x h x l(-1) (5.14-60.8). A ratio of plasma M8/plasma nelfinavir (AUC(0-12h)) and intracellular M8/intracellular nelfinavir (AUC(0-12h)) gave median values of 0.32 and 0.17, respectively. The cellular accumulations [median; (range)] of nelfinavir and M8 were 5.30 (2.28-16.2) and 2.32 (1.01-10.7), respectively. A significant correlation between plasma and intracellular nelfinavir minimum concentration (Cmin) (r2=0.34; P=0.049), but not between plasma and intracellular M8 Cmin was observed. C(0h) concentrations were higher than C(12h) for both nelfinavir and M8. No relationship was observed between nelfinavir or M8 accumulation and lymphocyte cell surface expression of P-gp. This study illustrates that intracellular concentrations were higher than plasma concentrations for both nelfinavir and M8, suggesting lymphocyte accumulation. The mechanism of differential intracellular accumulation of nelfinavir and M8 remains to be elucidated. It may be that affinities for influx transporters or fundamental drug characteristics play a major role in the greater accumulation of nelfinavir than M8.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

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