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P Chavanet

Publications and source records attributed to P Chavanet.

At least 19 recordsLinked to original sources
PubMed2007

Incidence of and risk factors for severe liver toxicity in HIV-infected patients on anti-tuberculosis treatment.

OBJECTIVE: To assess the incidence and risk factors for severe liver toxicity in human immunodeficiency virus (HIV) infected patients on anti-tuberculosis treatment and the impact of patients' characteristics and concomitant medications instituted during the first week of antituberculosis treatment. METHODS: HIV-infected patients referred to six French hospitals between 1 January 1992 and 31 December 2004, with confirmed or 'presumptive' tuberculosis (TB). Liver toxicity was studied during the first 2 months of TB treatment. RESULTS: During the 12 years of the study period, 144 patients were enrolled. Severe liver toxicity developed in 15 (10.7%). The median time to development of liver toxicity was 14 days. In the univariate analysis, high baseline bilirubin levels (P = 0.004), CD4 cell counts between 50 and 100 cells/mm3 (P = 0.022) and the use of fluconazole (P = 0.0005) were associated with liver toxicity. In the multivariate analysis, independent risk factors were abnormal baseline alanine aminotransferase (ALT) (P = 0.028) and bilirubin levels (P = 0.033) and the use of fluconazole (P = 0.008). CONCLUSION: Severe liver toxicity is frequent, and occurs early in the course of anti-tuberculosis treatment. ALT and bilirubin levels should be closely monitored during the first month of treatment, especially in patients with high baseline ALT or bilirubin levels. We suggest caution when prescribing fluconazole and anti-tuberculosis drugs concomitantly, although this needs to be confirmed and further investigated.

AIDS-Related Opportunistic Infections↗
PubMed2006

[Mutation window for the "pneumococcus-fluoroquinolone" couple. Contribution of experimental models].

Low-level resistance to fluoroquinolones (in vitro susceptible but with topoisomerase mutation, parC) is currently rare among pneumococci in France. However, this resistance is more frequently observed in previously exposed patients and therapeutic failure has been reported. These issues were investigated by using a humanized model of experimental pneumonia induced by pneumococci exhibiting this low-level resistance profile. The results are as follows: 1) when the pneumonia is due to a wild type pneumococcus, humanized ciprofloxacin treatment is not effective because of resistant mutants with parC mutation; moreover, levoflaxin treatment is less bactericidal than gatiflo- or moxifloxacin (-4 vs -6 log CFU/g); 2) when an efflux strain is used, levo-treatment is not efficient but there are no mutants, a gatiflo-treatment is combined when mutants appear and moxiflo-treatment is effective; 3) when the pneumonia is induced with susceptible parC strains, treatment with either levo, or gati, or moxifloxacin is completely ineffective because resistant mutants appear (acquisition of another gyrA mutation). Measure of the mutation prevention concentration (MPC) allows anticipating these results since the mutation window can be determined. These results stress the necessity to identify patients with such pneumococcal strains in order to avoid therapeutic failure and the emergence of fluoroquinolone resistant mutants.

Animals↗
PubMed2006

[Pyogenic psoas abscess: six cases and review of the literature].

PURPOSE: Psoas abscess is a rare disease in developed countries. Its diagnosis is difficult and any delay could lead to a worsen prognosis. The aim of this study is to determine the best diagnostic and therapeutic practices. METHODS: A retrospective study of psoas abscess that occurred during six months was performed. RESULTS: Six cases of secondary psoas abscess are reported. They were associated with spondylodiscitis in three cases, arthritis and gynaecologic infection in the three remaining cases. Anatomic diagnosis was performed by tomodensitometry. Microbiologic diagnosis was obtained by blood culture or direct puncture of the abscess. Antibiotics were associated with percutaneous drainage in two cases, with simple puncture in one case, and with surgery in one case. A local improvement w observed in all cases. The oldest patients presented the worst complications which were not directly caused by the abscess. CONCLUSION: Physicians must be aware of psoas abscess because of their increasing incidence. Despite the fact that digestive pathologies are the main cause of secondary psoas abscess, bone infections, particularly spine infections, should be taken into consideration. Tomodensitometry guided puncture or percutaneous drainage are of diagnostic and therapeutic interest. Infectious samples must be taken before starting antibiotics, which have to be efficient against Gram negative bacillus, anaerobes and Staphylococcus aureus. Surgery must be quickly performed when the primary infection localisation need it, in case of voluminous abscess or when antibiotics and drainage are inefficient.

Adult↗
PubMed2006

In-vivo impact of the MexXY efflux system on aminoglycoside efficacy in an experimental model of Pseudomonas aeruginosa pneumonia treated with tobramycin.

Aminoglycosides are of major importance in treating Pseudomonas aeruginosa pneumonia (PAP). However, their efficacy may be compromised by low-level resistance caused by the inducible MexXY multidrug efflux pump. In the present study, the impact of the MexXY efflux pump was investigated in vivo in an experimental model of PAP in rabbits treated with intravenous tobramycin. Three strains were used to induce PAP in rabbits: PAO1 (wild-type strain; MIC 1 mg/L), mutant 11B (mexX::Tn501; no expression of MexXY; MIC 0.5 mg/L) and mutant MutGR1 (MexZ null; constitutive expression of MexXY; MIC 2 mg/L). Five hours after inoculation, treatment with tobramycin (10 mg/kg) was implemented (peak serum concentration 30 mg/L). The animals were killed humanely 48 h after inoculation, and the residual pulmonary bacterial concentration was determined. Selection of bacteria expressing MexXY was determined by plating lung homogenates on agar plates containing antibiotic. Mean bacterial counts (log(10) CFU/g) for treated vs. untreated rabbits were 6.26 and 8.13 (p < 0.0001), 6.00 and 8.38 (p < 0.001), and 7.25 and 8.79 (p 0.04) for PAO1, 11B and MutGR1, respectively, with an overall mortality rate of 0% vs. 8.9% (p < 0.01). MexXY-overexpressing bacteria were recovered from three (21%) treated rabbits. The C(max)/MIC ratio was the parameter that was best associated with tobramycin efficacy. The bacteria overexpressing MexXY, recovered from lung, occurred with a C(max)/MIC window of 19-26. It was concluded that the experimental PAP model highlights poor tobramycin bacteriological efficacy in vivo, contrasting with survival gain, and that the contribution of the MexXY system to this low level of tobramycin efficacy is modest. Finally, this model appears to be suitable for the investigation of new anti-pseudomonal therapeutic strategies.

Animals↗
PubMed2005

[Low-level resistance to fluoroquinolones conferred by efflux overproduction in Pseudomonas aeruginosa: clinical significance and routine detection].

The aim of this study was (i) to assess the impact of stable overproduction of efflux systems MexAB-OprM and MexXY-OprM on the bacteriostatic activities of fluoroquinolones in clinical Pseudomonas aeruginosa strains and (ii) to find a convenient test for screening isolates with a low level resistance to fluoroquinolones. The minimal inhibitory concentrations (MICs) of ciprofloxacin and levofloxacin were determined for clinical isolates of P. aeruginosa overexpressing MexAB-OprM or MexXY-OprM. Efflux pumps derepression was associated with a modest two- to fourfold increase in resistance to the tested fluoroquinolones. Clinical significance of low level resistance conferred by the efflux mechanism was evaluated with a Monte Carlo simulation with various fluoroquinolone regimens. With this model, low levels of resistance to ciprofloxacin (MIC > or =0.25 mg/L) or levofloxacin (MIC > or =1 mg/L) such as those due to overproduced MexAB-OprM or MexXY-OprM were predicted to result in poor clinical outcomes. Altogether these data strongly suggest that when derepressed MexAB-OprM or MexXY-OprM provides P. aeruginosa with a resistance that may be sufficient to impair the efficacy of single therapy with highly potent fluoroquinolones such as ciprofloxacin and levofloxacin. Routine detection of clinical strains that displayed low-level resistance to fluoroquinolones with a Mueller Hinton agar containing 0.20 mg/L of ciprofloxacin will help clinician in his therapeutical choice.

Anti-Infective Agents↗
PubMed2004

[Predictive factors of virological response to primary antiretroviral treatment].

OBJECTIVES: During 1999, first-line antiretroviral combinations for the treatment of HIV infections have diversified. The aim of our study was two-fold: define the factors associated with initial success and define the factors associated with virological rebound in patients in whom a primary antiretroviral therapy (ARV) had been initiated between 1999 and 2000. METHOD: We conducted a retrospective multicenter study regrouping 6 HIV clinics in the North-East of France. Data were Issued from the patients medical files. Primary success was defined as plasma HIV RNA viral load (VL<200 copies/ml within 6 Months of therapy and two consecutive VL<200 copies/ml. Virological rebound was defined as two consecutive VL>1000 copies/ml after primary success. Predictors of success were determined using multivariate logistic regression and SAS 8.2 software. RESULTS: Analysis concerned 123 patients, with 19% stage C when ARV was initiated. Their median CD4 and PVL values at baseline were 233/mm3 and 73,000 copies/ml respectively. The median duration of follow-up was of 20.7 Months [(mean (STD): 20.6 (6.7)]. Initial treatments were distributed as follows: 2 NRTI + 1NNRTI, n=66 (54%); 2 NRTI+1PI, n=44 (36%); 3 NRTI, n=13 (10%). Primary success was obtained in 100 (81,3%) patients. Among these, 6 (6%) developed secondary virologic failure. The absence of change in initial ARV treatment within first 4 Months, and good compliance to treatment were statistically associated with primary success in univariate (p values respectively: 0.004 and 0.04) and in multivariate analysis (p respectively: 0.009 and 0.03). The proportion of failure was higher in the patients with lower baseline CD4 levels lesser than 200/mm3 (p=0.09). CONCLUSION: In this cohort of patients, tolerance and compliance to the first regimen were associated to primary success. These results emphasize the role of compliance in primary success and reinforces need to work on compliance in such patients.

Adult↗
PubMed2003

[Is there an increased risk for cardiovascular disease in HIV-infected patients on antiretroviral therapy?].

There is a growing concern about an increased risk for cardiovascular disease in HIV infected patients receiving antiretroviral therapy (ART). This risk could be related to metabolic abnormalities associated with long-term use of antiretroviral drugs. In fact, well recognized cardiovascular risk factors such as hypertension, dyslipidaemia, diabetes mellitus and central fat deposition are increasingly seen in HIV patients on ART. These factors can also be associated with non reversible risk factors, such as male sex, age greater than 40 years and family history of premature coronary artery disease. In addition, cigarette smoking and sedentary lifestyle may predispose these patients to significant cardiovascular disease. A direct atherogenic effect of HIV infection itself or antiretroviral drugs is unlikely. Epidemiological studies have suggested an increased risk for coronary artery disease in HIV infected persons; nevertheless, only long term follow-up could confirm this statement. Despite these uncertainties, it seems reasonable to identify and manage cardiovascular risk factors in HIV infected patients.

Adult↗
PubMed2002

Exercise stress testing for detection of silent myocardial ischemia in human immunodeficiency virus-infected patients receiving antiretroviral therapy.

The prevalence of silent myocardial ischemia (SMI) and the factors associated with SMI were evaluated in patients infected with human immunodeficiency virus (HIV) who had been receiving highly active antiretroviral therapy (HAART) for > or =12 months and did not have known coronary artery disease or cardiac symptoms. Patients prospectively underwent exercise stress testing. The prevalence of SMI was 11% (11 of 99 patients). Patients who had SMI were significantly older than were patients who did not (mean+/-SD, 51+/-8 years vs. 42+/-9 years; P=0.001) and were more likely to have trunk obesity (54% of patients vs. 17%; P=.004). A significant correlation was found between a positive exercise test result and obesity (correlation,.006), waist-to-hip ratio (.007), and glucose and cholesterol levels (.04; P=.03). In multivariate analysis, age, central fat accumulation, and cholesterol level were independent variables associated with the detection of SMI. Exercise testing might be recommended for patients with HIV who have central fat accumulation and hypercholesterolemia.

Adult↗
PubMed2001

Association between insulin resistance and hepatitis C virus chronic infection in HIV-hepatitis C virus-coinfected patients undergoing antiretroviral therapy.

Insulin resistance (IR) in the context of highly active antiretroviral therapy (HAART) is becoming more common in HIV-infected patients. Patients with chronic hepatitis C virus (HCV) infection have an increased risk of IR and type 2 diabetes mellitus. A cross-sectional study was performed to investigate whether chronic HCV infection constitutes a risk factor for IR in HIV-HCV-coinfected patients undergoing HAART. Inclusion criteria were positive HCV viremia and a sustained increase of alanine aminotransferase of at least twice the normal value. A total of 29 HIV-HCV patients, 76 HIV patients, and 121 HCV controls were tested for IR and body mass index (BMI). IR was measured using the homeostasis model assessment. In HIV-HCV and HIV patients, fat redistribution and lipid profile were assessed. There was no significant difference in age, CD4 cell count, HIV viral load, or duration of HAART between the HIV-HCV and HIV groups. HIV-HCV patients and HCV controls had a significant increase in IR when compared with HIV patients (0.25 +/- 0.28 and 0.21 +/- 0.34 versus 0.04 +/- 0.37; p =.01 and p =.003, respectively). Lipoatrophy was observed more frequently in HIV-HCV patients in comparison with HIV patients (41% versus 14%; p =.003). In HIV-HCV patients, total cholesterol and triglyceride levels were significantly lower than in HIV patients. In multivariate analysis, IR, BMI, triglyceride levels, and peripheral fat wasting were the independent variables associated with HCV infection. Our findings suggest that chronic HCV infection is a significant factor associated with the development of metabolic abnormalities and with modifications in body composition in HIV patients receiving antiretroviral treatment.

Adult↗
PubMed2001

Value of patient self-report and plasma human immunodeficiency virus protease inhibitor level as markers of adherence to antiretroviral therapy: relationship to virologic response.

Three methods of adherence to antiretroviral therapy were evaluated for 149 patients infected with human immunodeficiency virus (HIV): plasma level of protease inhibitors (PIs), patient self-report, and routine biological parameters associated with the use of some antiretroviral drugs. Adherence to therapy was estimated from a score calculated from answers to a self-administered questionnaire and on the basis of measurement of relevant plasma and blood levels. Of the 149 patients, 112 had a virologic response, and 122 had adequate trough PI levels. Plasma PI levels and virologic outcome were significantly correlated (P<.0001). The adherence score was significantly correlated with virologic response (P<.001). Macrocytosis was significantly associated with virologic response in the patients treated with zidovudine or stavudine (P=.006). PI level was the higher significant predictor of virologic response (P=.0003). Self-reported adherence (P=.01) and macrocytosis (P=.05) were also independently associated with antiretroviral efficacy.

Adult↗
PubMed2001

Need for alternative trial designs and evaluation strategies for therapeutic studies of invasive mycoses.

Studies of invasive fungal infections have been and remain difficult to implement. Randomized clinical trials of fungal infections are especially slow and expensive to perform because it is difficult to identify eligible patients in a timely fashion, to prove the presence of the fungal infection in an unequivocal fashion, and to evaluate outcome in a convincing fashion. Because of these challenges, licensing decisions for antifungal agents have to date depended heavily on historical control comparisons and secondary advantages of the new agent. Although the availability of newer and potentially more effective agents makes these approaches less desirable, the fundamental difficulties of trials of invasive fungal infections have not changed. Therefore, there is a need for alternative trial designs and evaluation strategies for therapeutic studies of invasive mycoses, and this article summarizes the possible strategies in this area.

Antifungal Agents↗
PubMed2001

Coronary heart disease associated with the use of human immunodeficiency virus (HIV)-1 protease inhibitors: report of four cases and review.

Four cases of human immunodeficiency virus (HIV)-infected patients who developed coronary heart disease (CHD) while under treatment with a protease inhibitor (PI) are described, and the epidemiologic and clinical features of 18 cases reported in the literature are analyzed. Cardiac manifestations mostly included myocardial infarctions. Smoking and hyperlipidemia were the most common risk factors for CHD, reported in 72 and 81% of the patients, respectively. Hypercholesterolemia was observed in 75% of the cases at the time of the cardiovascular event. Ninety percent of the patients with pretreatment normal lipid values experienced a rise in the plasma lipid levels during PI therapy. Although a definite relationship between the development of CHD and HIV PIs can not be made, this analysis suggests that PI-induced hyperlipidemia may play a role in accelerating coronary atherosclerosis in patients with concomitant risk factors. Evaluation and control of risk factors for CHD should be performed in each patient for whom treatment with a PI is indicated.

Adolescent↗
PubMed2001

Decrease in Candida albicans strains with reduced susceptibility to fluconazole following changes in prescribing policies.

This study was undertaken to identify prescribing policies likely to favour or limit fluconazole resistance within a clinical department. Fluconazole exposure within the infectious diseases and clinical haematology units was investigated, and data were compared with in vitro susceptibility of Candida albicans isolates obtained in these units. Fluconazole utilization was determined by the number of fluconazole treatment-days per 100 hospitalization days (penetration index). In the infectious diseases unit, separate evaluations for low-dose fluconazole (50 mg) prescribed as intermittent or prolonged treatment, and for higher-dosing schedules (fluconazole 200 mg) were made. Susceptibility of C. albicans isolates was surveyed in a broth microdilution assay by measuring the inhibitory concentration 50% (IC50). The penetration index (PI) for fluconazole 50mg declined from 1992 to 1977 in infectious diseases (P= 0.0048). In the meantime, total usage of fluconazole increased, due to increased prescribing of fluconazole 200 mg (P = 0.0724). The IC50 of C. albicans isolates tested in infectious diseases decreased between 1994 and 1996 from 7.33 mg/ml to 1.64 mg/ml (P = 0.0075). In clinical haematology, declines in C. albicans IC50 and fluconazole PI were not significant (P = 0.35 and P = 0.07, respectively). These data suggest that prolonged or repeated exposure to low-dose fluconazole, rather than total cumulative use, was associated with fluconazole resistance in the infectious diseases unit. Moreover, restoration of a normal ecology was observed when low-dose prolonged or intermittent prescriptions were reduced.

Analysis of Variance↗
PubMed2001

HMR 3647 human-like treatment of experimental pneumonia due to penicillin-resistant and erythromycin-resistant Streptococcus pneumoniae.

An experimental Streptococcus pneumoniae pneumonia model in rabbits was used to assess the efficacy of amoxycillin, erythromycin and a new ketolide, telithromycin (HMR 3647). The MICs of amoxycillin, erythromycin and HMR 3647 for the three clinical S. pneumoniae strains used were, respectively, (mg/L): 0.01, 16 and 0.02 (strain 195); 2, 0.25 and 0.02 (strain 16089); 8, >64 and 0.02 (strain 11724). Antibiotic therapy reproduced human serum pharmacokinetics (amoxycillin 1 g iv tds or erythromycin 500 mg qds or HMR 3647 800 mg bd). Forty-eight hours of therapy with HMR 3647 and amoxycillin resulted in significant bacterial clearance in the lungs and spleen of rabbits infected by S. pneumoniae strain 195 and strain 16089 (at least 3 log(10) cfu/g decrease, P < 0.001). Erythromycin was active against only the erythromycinsusceptible strain (3 log(10) cfu/g decrease at 48 h, P < 0.001). None of the antibiotics showed significant efficacy with strain 11724. All agents produced significant bacterial clearance when time above MBC was >33%, and microbiological failure when it was <25%, whereas MIC was not correlated with microbiological outcome with HMR 3647. Our findings suggest that pharmacodynamic data integrating MBC may be predictive of microbiological success or failure with greater accuracy than with MIC. HMR 3647 produced significant bacterial clearance in both penicillin- and erythromycin-resistant pneumonia, but was less effective against the highly erythromycin-resistant S. pneumoniae strain.

Amoxicillin↗
PubMed2001

Fractional maximal effect method for in vitro synergy between amoxicillin and ceftriaxone and between vancomycin and ceftriaxone against Enterococcus faecalis and penicillin-resistant Streptococcus pneumoniae.

In the present study we assessed the use of a new in vitro testing method and graphical representation of the results to investigate the potential effectiveness of combinations of amoxicillin (AMZ) plus ceftriaxone (CRO) and of CRO plus vancomycin (VAN) against strains of Streptococcus pneumoniae highly resistant to penicillin and cephalosporins (PRP strains). We used the fractional maximal effect (FME) method of time-kill curves to calculate adequate concentrations of the drugs to be tested rather than relying on arbitrary choices. The concentrations obtained, each of which corresponded to a fraction of the maximal effect, were tested alone and in combination with the bacterial strains in a broth medium. Synergy was defined as a ratio of observed effect/theoretical effect, called FME, of greater than 1, additivity was defined as an FME equal to 1, and antagonism was defined as an observed effect lower than the best effect of one of the antibiotics used alone. The area between antagonism and additivity is the indifference zone. The well-known synergy between amoxicillin and gentamicin against a reference strain of Enterococcus faecalis was confirmed, with a best FME equal to 1.07. Two strains of PRP, strains PRP-1 and PRP-2, were studied. The MICs for PRP-1 and PRP-2 were as follows: penicillin, 4 and 16 microg/ml, respectively; AMZ, 2 and 8 microg/ml, respectively, CRO, 1 and 4 microg/ml, respectively; and VAN, 0.5 and 0.25 microg/ml, respectively. For PRP-1 the best FME for the combination AMZ-CRO was 1.22 with drug concentrations of 1.68 mg/liter for AMZ and 0.17 mg/liter for CRO; the best FME for the combination VAN-CRO was 1.75 with VAN at 0.57 mg/liter and CRO at 0.17 mg/liter. For PRP-2 the best FME obtained for the combination AMZ-CRO was 1.05 with drug concentrations of 11.28 mg/liter for AMZ and 0.64 mg/liter for CRO; the best FME obtained for the combination VAN-CRO was 1.35 with VAN at 0.25 mg/liter and CRO at 1.49 mg/liter. These results demonstrated the synergy of both combinations, AMZ-CRO and VAN-CRO, against PRP strains at drug concentrations achievable in humans. Consequently, either of the combinations can be proposed for use for the treatment of PRP infections.

Amoxicillin↗