Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Efavirenz is a nonnucleoside reverse transcriptase inhibitor that can be given with other antiretroviral agents for the treatment of human immunodeficiency virus infection. A 47-year-old man with acquired immunodeficiency syndrome developed severe depression and suicidal ideation necessitating psychiatric hospitalization and antidepressant therapy. The symptoms occurred in temporal relation to the introduction of efavirenz into his highly active antiretroviral therapy regimen. Similar serious psychiatric adverse effects have been associated with this agent. Clinicians should monitor for central nervous system adverse effects in all patients taking efavirenz.
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PMID:Central nervous system adverse effects with efavirenz: case report and review. 1212 26

We evaluated the therapeutic outcomes of all antiretroviral-naive HIV-1-infected patients with fewer than 100 CD4 cells/microl, who received efavirenz-based highly active antiretroviral therapy (HAART). Sixty-one percent suffered AIDS-defining diseases, and after a median follow-up of 45 weeks there were three deaths and five AIDS-related conditions (two relapses, three new). Efavirenz-based HAART was found to be effective in profoundly immunosuppressed HIV-1-infected patients.
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PMID:High effectiveness of efavirenz-based highly active antiretroviral therapy in HIV-1-infected patients with fewer than 100 CD4 cells/microl and opportunistic diseases: the EfaVIP Study (Efavirenz in Very Immunosuppressed Patients). 1213 Nov 95

Complex drug interactions involving antiretroviral agents and drugs for the management of opportunistic infections demand the monitoring of plasma drug concentrations to prevent treatment failure. The high occurrence of tuberculosis in HIV-infected subjects makes the management of HIV treatment complex. Rifampicin, a potent inducer of the cytochrome P 450 metabolic pathway, is a very active antituberculosis drug that accelerates the metabolism of protease inhibitors. Regimens containing efavirenz, a non-nucleoside reverse transcription inhibitor, could be an alternative, but efavirenz plasma concentrations may be altered after the coadministration of rifampicin. Efavirenz is also a cytochrome P 450 inducer and may alter rifampicin plasma levels. Due to the increasing need to monitor plasma concentrations in HIV patients with tuberculosis, a high-performance liquid chromatographic (HPLC) method has been developed to measure rifampicin and efavirenz at the same time in a small amount of sample. This HPLC method is highly sensitive and precise, suitable for pharmacokinetic studies or routine clinical monitoring of rifampicin and efavirenz simultaneously in HIV patients with tuberculosis.
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PMID:Simultaneous determination of rifampicin and efavirenz in plasma. 1235 41

Efavirenz and nevirapine are non-nucleoside reverse transcriptase inhibitors for the treatment of HIV-1-infected individuals. A simple and rapid high-performance liquid chromatographic method for the simultaneous quantification of efavirenz and nevirapine in human plasma suitable for therapeutic drug monitoring is described. Sample pre-treatment consisted of protein precipitation with acetonitrile and subsequently dilution with distilled water. The drugs were separated from endogenous compounds by isocratic reversed-phase high-performance liquid chromatography with ultraviolet detection at 275 nm. The method was validated over the therapeutically relevant concentration range of 0.05-15.0 mg l(-1) and 0.25-15.0 mg l(-1) for efavirenz and nevirapine, respectively, using a volume of 100 microl of plasma. The calibration curves were linear over this concentration range. Carbamazepine was used as internal standard. The assay proved to be accurate (accuracies varied between -12.7 and 8.5%) and precise (intra- and inter-assay precisions were less then 5.9%). The tested batches of control human plasma and frequently co-administered drugs did not interfere with the described methodology. Efavirenz and nevirapine were stable under various relevant storage conditions. This validated assay is suited for use in pharmacokinetic studies with efavirenz and nevirapine and can readily be implemented in the setting of a hospital laboratory for the monitoring of efavirenz and nevirapine concentrations.
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PMID:Simple and rapid method for the simultaneous determination of the non-nucleoside reverse transcriptase inhibitors efavirenz and nevirapine in human plasma using liquid chromatography. 1286 43

There is marked variability in the extent to which the three classes of antiretroviral (ARV) drugs bind to plasma proteins (<5 to >99%). Protease inhibitors (PIs), with the exception of indinavir, are more than 90% protein bound, mainly to alpha1-acid glycoprotein (AAG). Efavirenz, a nonnucleoside reverse transcriptase inhibitor (NNRTI), is more than 99% bound, mainly to albumin. Nucleoside reverse transcriptase inhibitors (NRTIs) are not highly protein bound. The pharmacological activity of ARV drugs is dependent on unbound drug entering cells that harbor the human immunodeficiency virus (HIV). There has been concern that changes in protein binding could impact on antiviral activity and management. However, for PIs and NNRTIs, and for many drugs given orally, altered plasma binding would not be expected to influence the average exposure to unbound (active) drug after chronic oral dosing. Nevertheless, there will be a change in the relationship between total and unbound concentrations that will be important if, as part of therapeutic drug monitoring, the total rather than the unbound drug is measured. Measuring drug concentrations that are needed to inhibit different HIV strains (wild type and drug resistant) in vitro could also cause confusion because most methods employ bovine serum in the assay medium, and unbound concentrations are not directly measured. Estimating unbound drug concentrations in human plasma and in incubation media can be highly method dependent and thus may affect the calculated IC50 (the concentration of drug that results in 50% inhibition of viral replication). Because inhibitory quotients (IQs = C(trough)/IC50) are becoming part of pharmacokinetic/pharmacodynamic (PK/PD) analyses of clinical trial data, the strengths and weaknesses of the methods used for the determination of unbound drug concentration in plasma and in vitro systems--ultracentrifugation, ultrafiltration, and equilibrium dialysis--need to be understood. Consensus on standard procedures must be reached. In June 2002, a panel of experts assembled by the Forum for Collaborative HIV Research met in Washington, DC, to review the basic principles of protein binding of ARV drugs, and to discuss the impact that changes in plasma protein binding may have on the PKs and activity of ARV drugs as well as on therapeutic drug monitoring. The purpose of the meeting was to discuss the following topics: (1) basic principles of protein binding and how changes in binding can impact on drug PKs and drug exposure in vivo, (2) variability in plasma protein binding among patients taking ARV drugs, (3) the impact of HIV infection and concomitant diseases on the extent of plasma protein binding, (4) the likelihood of clinically relevant drug interactions at the level of plasma protein binding, (5) the evidence that measuring unbound concentrations of ARV drugs in the plasma of patients gives more meaningful information than total drug concentration and, therefore, should be considered in routine therapeutic drug monitoring of ARV agents, (6) optimal method(s) for measuring the unbound concentration of drugs in vitro (for IC50 determination) and in vivo, and (7) future studies that need to be considered to fully understand the importance of plasma protein binding in therapeutic drug monitoring. This report summarizes the topics discussed at this meeting. It guides the reader through the discussions that allowed the panel to formulate a series of statements regarding the significance of plasma protein binding of ARV drugs when studied in vitro and in vivo. The roundtable participants also identified research priorities that are important for understanding the sources of inter- and intraindividual variability in protein binding in patients. These include obtaining data on unbound as well as on total concentrations in PK studies; looking at variants of AAG and whether they differ in binding affinity; and emphasizing the importance of developing a standard procedure for drug susceptibility assays used to determine IC50 values.
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PMID:Protein binding in antiretroviral therapies. 1458 13

Ambulatory electroencephalogram monitoring was performed for 18 HIV-infected subjects treated with efavirenz with and without insomnia and for 13 healthy control subjects. All patients receiving efavirenz had longer sleep latencies and shorter duration of deep sleep, although poor sleepers also showed reduced sleep efficiency and shorter duration of rapid eye movement sleep. Efavirenz plasma levels were higher in patients with insomnia and/or reduced sleep efficiency.
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PMID:Analyzing sleep abnormalities in HIV-infected patients treated with Efavirenz. 1472 17

Gynecomastia has been reported to occur in HIV-infected patients receiving HAART. A retrospective case-control study was conducted to determine risk factors associated with this condition. Two control patients were randomly chosen for each of 23 case patients identified. An efavirenz-containing regimen was strongly associated with the development of gynecomastia (odds ratio, 20; P < .001). Case patients were not more likely to have lipodystrophy, low testosterone levels, chronic infection with hepatitis B or C virus, or liver dysfunction compared with control patients. None of these factors altered the efavirenz-associated risk when analyzed by multiple logistic regression. Efavirenz appears to be strongly associated with gynecomastia in HIV-infected patients receiving HAART.
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PMID:A case-control study of gynecomastia in HIV-1-infected patients receiving HAART. 1495 2

This paper reports the synthesis and the antiviral activities of a series of 6-arylvinyl substituted analogues of SJ-3366, a highly potent agent against HIV. The objective was to investigate whether substitution of the 6-arylketone with a 6-arylvinyl group could lead to an improved antiviral activity against HIV-1. The most active compounds 1-ethoxymethyl, 1-(2-propynyloxymethyl), and 1-(2-methyl-3-phenylallyloxymethyl) substituted 6-[1-(3,5-dimethylphenyl)vinyl]-5-ethyl-1H-pyrimidine-2,4-dione (5b, 16, and 18) showed activities against HIV-1 wild type in the range of Efavirenz, and moderate activities against Y181C and Y181C+K103N mutant strains were also observed.
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PMID:Synthesis of 6-arylvinyl analogues of the HIV drugs SJ-3366 and Emivirine. 1498 Jun 26

A pharmacokinetics study was performed in HIV-infected patients who used indinavir/ritonavir (800/100 mg twice a day) plus efavirenz in the European and South American Study of Indinavir, Efavirenz and Ritonavir. Indinavir plasma concentrations were similar to values previously obtained in healthy volunteers who used the same combination. Efavirenz concentrations were higher than reported before. The pharmacokinetic data suggest that indinavir/ritonavir plus efavirenz (without dose modifications) should be effective in treatment-naive patients, and this was supported by the treatment response of the participants.
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PMID:Pharmacokinetics of indinavir/ritonavir (800/100 mg twice a day) combined with efavirenz in HIV-infected patients. 1509 Aug 12

Efavirenz is a drug subject to extensive metabolism, mainly by the cytochrome P-450 isoenzyme CYP2B6, known to exhibit extensive interindividual variability. The aim of the present study was 2-fold: to investigate the relationship between plasma concentration and clinical effects of efavirenz and to investigate the extent of the inter- and intraindividual variability of the plasma concentration measurements. From an open clinic, 68 HIV-positive patients on efavirenz-containing treatment were recruited. From each patient 1 to 5 samples were collected; 43 had more than 1 sample taken. Most samples were taken 10-24 hours after the latest dose. Efavirenz was analyzed by high-performance liquid chromatography with UV detection. The data were analyzed by the variance component model analysis of variance. Efavirenz concentrations were reproducible, and intraindividual variability constituted only 16% of the total variance. Thus, 84% of the variance was attributed to interindividual variability. The incidence of primary treatment failure was related to low plasma concentrations with a geometric mean concentration of 6.1 micromol/L compared with 8.7 micromol/L in those responding to therapy (P < 0.05). If a cutoff of 7 micromol/L is used, 10 of 13 failing to respond were below this level compared with 15 of 45 in those responding. It is concluded that efavirenz plasma concentration measurement gives reproducible results predictive of primary treatment failure. A lower bound for the therapeutic level of 7 micromol/L is proposed, and data from other authors suggests that an upper level of 13 micromol/L may be applied.
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PMID:Efavirenz plasma concentrations in HIV-infected patients: inter- and intraindividual variability and clinical effects. 1516 26


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