Detection of stavudine concentrations in plasma of HIV-infected patients taking zidovudine.
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Biomedical subjects
Publications and source records attributed to Giovanni Di Perri.
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Abnormal liver function tests are frequently observed in HIV-infected individuals receiving nevirapine (NVP). Here we investigate the relationship between total and unbound plasma concentrations of NVP and the liver enzymes alanine aminotransferase (ALT) and gamma-glutamyl transferase (gammaGT). HIV-infected individuals [n = 85, 22 female, 34 hepatitis C or B virus (HCV or HBV(+))] receiving NVP (200 mg bd; median duration 66 weeks, range 3-189) and two nucleoside reverse transcriptase inhibitors (NRTIs) were enrolled into this study. Blood samples were taken at C(trough) (12 hr postdose) for measurement of NVP and liver function tests (ALT and gammaGT). Plasma protein bound and unbound drug was separated using ultrafiltration and NVP concentrations quantified using HPLC-MS/MS. A linear relationship was observed between total and unbound NVP C(trough) (r(2) = 0.77, p < 0.0001). Patients with elevated ALT (>37 IU/liter; n = 31) had higher NVP unbound C(trough) than those with ALT within the normal range (median 2268 vs. 1694 ng/ml, p = 0.04) but there was no difference in total C(trough). Logistic regression revealed no association between higher NVP C(trough) and ALT elevations. Significantly higher NVP total and unbound C(trough) were observed in patients with increased gammaGT (>40 IU/liter; n = 63; total 6747 vs. 4530 ng/ml, p = 0.001; unbound 2113 vs. 1557 ng/ml, p = 0.03). Significantly higher unbound NVP C(trough) was observed in HCV/HBV(+) (median 2275 vs. 1726 ng/ml, p = 0.02) and on bivariate analysis, higher NVP C(trough) was associated with HCV/HBV coinfection (chi(2) = 4.228; p = 0.04). Overall we found no strong association between NVP concentrations and hepatotoxicity. Although in this study NVP was well tolerated in HCV/HBV coinfected patients, higher plasma concentrations were observed.
Most protease inhibitors available for the treatment of human immunodeficiency virus (HIV) infection are highly bound to plasma proteins, mainly alpha-1 acid glycoprotein. Therapeutic drug monitoring (TDM) of total protease inhibitor (PI) concentrations has been increasing in the past few years; however, the pharmacological activity of the PIs is dependent on unbound drug entering cells harboring HIV. There is little information available on unbound drug concentrations of these drugs in vivo. The aim of the study was to measure unbound plasma concentrations of lopinavir (LPV) and to relate them to the total plasma concentrations to establish the unbound percentage in vivo during a full dosage interval. A pharmacokinetic study was performed in HIV-infected subjects (n = 23; median CD4 cell count = 290 x 10(6) cells x L(-1); viral load < 50 copies x mL(-1)) treated with a LPV/ritonavir (RTV)-containing regimen. Ultrafiltration was used to separate unbound LPV in all plasma samples (n = 115). Equilibrium dialysis was also used to compare with ultrafiltration measurements in 10/23 patients at baseline and 2 hours after drug intake. Total and unbound LPV concentrations were measured by a fully validated method using high-performance liquid chromatography-mass spectometry (HPLC-MS/MS). Based on a comparison of AUC(unbound)AUC(total), the mean (+/- SD) unbound percentage of LPV from all the samples studied (n = 115) was 0.92% (+/- 0.22) when measured with ultrafiltration and 1.32% (+/- 0.44) when equilibrium dialysis was used (n = 20), showing a higher drug recovery (P = 0.048). The unbound percentage of LPV was found to be significantly higher after 2 h than at baseline (P < 0.05 with both methods), suggesting a concentration-dependent binding of LPV that has not been observed in vitro. However, the clinical significance of such phenomena is still unclear.
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Since their advent the nucleoside and nucleotide reverse transcriptase inhibitors have consolidated their position as the 'backbone' of many antiretroviral therapy regimens. The ability of this class of drugs to combine successfully with members of their own as well as other antiretroviral classes has enabled the effective suppression of HIV replication to occur. Many of these therapeutic combinations rely on synergistic interactions to achieve this. There are, however, also many unfavourable pharmacokinetic and pharmacodynamic interactions between the members of nucleoside/nucleotide reverse transcriptase inhibitors, as well as with other antiretroviral classes and non-HIV drugs. This article aims to identify clinically relevant, beneficial and detrimental interactions of this class of antiretroviral agent.
BACKGROUND: The objective of the current study was to evaluate the impact of highly active antiretroviral therapy (HAART) on clinical characteristics of presentation and the natural history of Kaposi sarcoma (KS) in patients already receiving HAART at the time of KS diagnosis. METHODS: The authors conducted a retrospective cohort study comparing epidemiologic, clinical, and outcome data for 160 patients who were naive to HAART at the time of KS diagnosis (KS-naive) with the corresponding data for 51 patients already receiving HAART at the time of KS diagnosis (KS-HAART). The analysis included all patients with a diagnosis of KS since January 1996 within two Italian cohorts of patients with human immunodeficiency virus. RESULTS: Immunologic and virologic status at the time of KS diagnosis were significantly more favorable in the KS-HAART group than in the KS-naive group. The frequency of cutaneous involvement was similar in both groups, but cutaneous disease was more indolent among KS-HAART patients, with 1 anatomic site of involvement in 9 patients (21%) and less than 10 lesions in 26 patients (60%), compared with 16 patients (12%; P = 0.06) and 47 patients (34%; P = 0.01), respectively, in the KS-naive group. A smaller proportion of KS-HAART patients presented with visceral disease (24% vs. 39%; P = 0.06); in particular, gastrointestinal tract involvement was significantly less frequent among KS-HAART patients (14%) compared with KS-naive patients (28%; P = 0.05). Median survival was not reached in either group, and the 3-year survival rates of KS-HAART patients (64%) and KS-naive patients (78%) were not significantly different. CONCLUSIONS: The data from the current study indicate that KS exhibits a less aggressive presentation in patients already receiving HAART compared with patients who are naive to HAART at KS diagnosis. Natural history and outcome do not appear to be influenced by the initiation of HAART before development of KS.
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PURPOSE: To assess potential new prognostic factors and to validate the AIDS Clinical Trials Group (ACTG) for AIDS-related Kaposi's sarcoma (AIDS-KS) staging system in the highly active antiretroviral therapy (HAART) era. PATIENTS AND METHODS: We collected epidemiologic, clinical, staging, and survival data from 211 patients with AIDS-KS enrolled in two prospective Italian human immunodeficiency virus (HIV) cohort studies. We included in the analysis all patients with the diagnosis of KS made from January 1996, the time at which HAART became available in Italy. RESULTS: In the univariate analysis, survival was not influenced by sex, age, level of HIV viremia at KS diagnosis, HAART at KS diagnosis (HAART-naïve v HAART-experienced), or type of HAART combination. Regarding ACTG classification, the 3-year survival rate was 85% for T0 patients and 69% for T1 patients (P =.007), 83% for S0 patients and 63% for S1 patients (P =.003), and 83% for I0 patients and 71% for I1 patients (P =.06). In the multivariate analysis, only the combination of poor tumor stage (T1) and poor systemic disease (S1) risk identified patients with unfavorable prognosis. The 3-year survival rate of patients with T1S1 was 53%, which was significantly lower compared with the 3-year survival rates of patients with T0S0, T1S0, and T0S1, which were 88%, 80%, and 81%, respectively (P =.0001). CONCLUSION: In the era of HAART, a refinement of the original ACTG staging system is needed. CD4 level does not seem to provide prognostic information. Two different risk categories are identified: a good risk (T0S0, T1S0, T0S1) and a poor risk (T1S1).
The 14-3-3 protein, a cerebrospinal fluid (CSF) marker of neuronal damage that was recently adopted for the diagnosis of Creutzfeldt-Jakob disease, is also found in the CSF of patients with a variety of neurological disorders. We prospectively studied 12 consecutive patients with purulent bacterial meningitis and found that 14-3-3 protein was detected in all patients at admission to the hospital. All patients who recovered cleared 14-3-3 protein from the CSF before discharge from the hospital (this was the first CSF marker to clear), whereas those who died never cleared the protein.
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Lopinavir/ritonavir was administered to 35 HIV-infected patients after therapeutic failure with other protease inhibitors. The pharmacokinetics (trough concentrations) and baseline viral genotype were determined, together with the immunovirological outcome. The 22 responders had significantly higher mean lopinavir concentrations and lower baseline numbers of mutations. On multivariate analysis, a lopinavir concentration of 5.7 microg/ml or greater was an independent predictor of viral suppression over a 9-month follow-up period.
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