17 research outputs found

    Population Pharmacokinetic Model and Meta-analysis of Outcomes of Amphotericin B Deoxycholate Use in Adults with Cryptococcal Meningitis

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    There is a limited understanding of the population pharmacokinetics (PK) and pharmacodynamics (PD) of amphotericin B deoxycholate (DAmB) for cryptococcal meningitis (CM). A PK study was conducted in n=42 patients receiving DAmB 1 mg/kg q24h. A 2-compartment PK model was developed. Patient weight influenced clearance and volume in the final structural model. Monte Carlo simulations estimated drug exposure associated with various DAmB dosages. A search was conducted for trials reporting outcomes of CM patients treated with DAmB monotherapy and a meta-analysis was performed.The PK parameter means (standard deviation) were: clearance, 0.03 (0.01) x weight + 0.95 (0.02) litres/hour; volume, 0.89 (0.90) x weight + 1.54 (1.13) litres; first-order rate constant from central to peripheral compartment, 7.12 (6.50) hours-1; from peripheral to central compartment, 12.13 (12.50) hours-1 The meta-analysis suggested that DAmB dosage explained most of the heterogeneity in cerebrospinal fluid (CSF) sterility, but not in mortality outcomes. Simulations of area under concentration-time curve (AUC144-168) resulted in median (interquartile range) values 5.83 mg.h/litre (4.66-8.55), 10.16 (8.07-14.55) and 14.51 (11.48-20.42), with dosages of 0.4, 0.7 and 1.0 mg/kg q24h respectively.DAmB PK is described adequately by a linear model that incorporates weight on clearance and volume. Inter-patient PK variability is modest and unlikely to be responsible for variability in clinical outcome. There is a discord between the impact that drug exposure has on CSF sterility and on mortality outcomes, which may be due to cerebral pathology not reflected in CSF fungal burden, in addition to clinical variables

    Population Pharmacokinetics and Cerebrospinal Fluid Penetration of Fluconazole in Adults with Cryptococcal Meningitis

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    Robust population pharmacokinetic (PK) data for fluconazole are scarce. The variability of fluconazole penetration into the CNS is not known. A fluconazole PK study was conducted in 43 patients receiving oral fluconazole (usually 800 mg q24h) in combination with amphotericin B deoxycholate (1 mg/kg q24h) for cryptococcal meningitis (CM). A 4-compartment PK model was developed and Monte Carlo simulations performed for a range of fluconazole dosages. A meta-analysis of trials reporting outcomes of CM patients treated with fluconazole monotherapy was performed. Adjusted for bioavailability, the PK parameter means (standard deviation) were: clearance, 0.72 (0.24) litres/hour; volume of the central compartment, 18.07 (6.31) litres; volume of central nervous system (CNS) compartment, 32.07 (17.60) litres; first-order rate constant from central to peripheral compartment, 12.20 (11.17) hours-1; from peripheral to central compartment, 18.10 (8.25) hours-1; from central to CNS compartment 35.43 (13.74) hours-1; from CNS to central compartment 28.63 (10.03) hours-1 Simulations of area under concentration-time curve resulted in median (interquartile range) values 1143.2 mg.h/litre (988.4 - 1378.0) in plasma and 982.9 (781.0 - 1185.9) in CSF after a dosage of 1200mg q24h. The mean simulated ratio of AUCCSF:AUCplasma was 0.89 (SD 0.44). The recommended dosage of fluconazole for CM induction therapy fails to attain the PD target in respect to the wild-type MIC distribution of C. neoformans The meta-analysis suggested modest improvements in both CSF sterility and mortality outcomes with escalating dosage. This study provides the pharmacodynamic rationale for the long-recognised fact that fluconazole monotherapy is an inadequate induction regimen for CM

    CryptoDex: a randomised, double-blind, placebo-controlled phase III trial of adjunctive dexamethasone in HIV-infected adults with cryptococcal meningitis: study protocol for a randomised control trial.

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    BACKGROUND: Cryptococcal meningitis (CM) is a severe AIDS-defining illness with 90-day case mortality as high as 70% in sub-Saharan Africa, despite treatment. It is the leading cause of death in HIV patients in Asia and Africa.No major advance has been made in the treatment of CM since the 1970s. The mainstays of induction therapy are amphotericin B and flucytosine, but these are often poorly available where the disease burden is highest. Adjunctive treatments, such as dexamethasone, have had dramatic effects on mortality in other neurologic infections, but are untested in CM. Given the high death rates in patients receiving current optimal treatment, and the lack of new agents on the horizon, adjuvant treatments, which offer the potential to reduce mortality in CM, should be tested.The principal research question posed by this study is as follows: does adding dexamethasone to standard antifungal therapy for CM reduce mortality? Dexamethasone is a cheap, readily available, and practicable intervention. METHOD: A double-blind placebo-controlled trial with parallel arms in which patients are randomised to receive either dexamethasone or placebo, in addition to local standard of care. The study recruits patients in both Asia and Africa to ensure the relevance of its results to the populations in which the disease burden is highest. The 10-week mortality risk in the control group is expected to be between 30% and 50%, depending on location, and the target hazard ratio of 0.7 corresponds to absolute risk reductions in mortality from 30% to 22%, or from 50% to 38%. Assuming an overall 10-week mortality of at least 30% in our study population, recruitment of 824 patients will be sufficient to observe the expected number of deaths. Allowing for some loss to follow-up, the total sample size for this study is 880 patients. To generate robust evidence across both continents, we aim to recruit roughly similar numbers of patients from each continent. The primary end point is 10-week mortality. Ethical approval has been obtained from Oxford University's Tropical Research Ethics Committee (OxTREC), and as locally mandated at each site. TRIAL REGISTRATION: International Standard Randomised Controlled Trial Number: ISRCTN59144167 26-July-2012

    Asian Chicken Genetic Gains (AsCGG) project update

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    China’s Unsubstantiated Claims on Baselines: Legal Consequences Affecting International Security

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    For all nations, the stability of the global order is a significant concern. Despite the efforts of the international community, Asia’s peace and security are threatened by China’s aggressive behaviours in the South China Sea. Accordingly, China has claimed nearly the whole South China Sea as its territory, including water internationally acknowledged as belonging to other nations. States have the right to determine and declare their baselines for coastal areas, islands, and archipelagos that fall under their national sovereignty with regard to international law of the sea. Because of the inconsistency with the rules of international law in general and the international law of the sea in particular, China’s claims in this case are unsubstantiated. This article aims to determine China's violations to comply with their obligations under international law, especially in the South China Sea disputes. By using analysed and evaluated methods, this study pointed out the regulations that violate international law contained in documents such as the Declaration of China on the baselines of the territorial sea in 1996, the Coast Guard Law of China in 2021, the Maritime Traffic Safety Law of China in 2021, by using the comparative methods of these documents with the provisions of the international law, particularly the United Nations Convention on the Law of the Sea in 1982. The article also highlights the severe effects of China's behavior on Vietnam, particularly the implementation of the two laws previously mentioned that violate Vietnam's territorial integrity in the Paracel and Spratly Islands. As a result,  the paper suggests certain notes for Vietnam and other nations to void China’s aforementioned legal documents. These suggestions, in particular, will contribute to protecting the sovereignty, sovereign rights, and jurisdiction of Vietnam, and the freedom of navigation and overflight of countries for nations across the world
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