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.

The results of a study to determine the physical compatibility of plazomicin sulfate solution during simulated Y-site administration with 92 i.v. drugs are reported.

An experimental micellar formulation of 1:1.5 amphotericin B-sodium deoxycholate (AMB:DCH 1:1.5) was obtained and characterized to determine its aggregation state and particle size. The biodistribution, nephrotoxicity, and efficacy against pulmonary aspergillosis in a murine model were studied and compared to the liposomal commercial formulation of amphotericin B after intravenous administration. The administration of 5 mg/kg AMB:DCH 1:1.5 presented 2.8-fold-higher lung concentrations (18.125 ± 3.985 μg/g after 6 daily doses) and lower kidney exposure (0.391 ± 0.167 μg/g) than liposomal commercial amphotericin B (6.567 ± 1.536 and 5.374 ± 1.157 μg/g in lungs and kidneys, respectively). The different biodistribution of AMB:DCH micelle systems compared to liposomal commercial amphotericin B was attributed to their different morphologies and particle sizes. The efficacy study has shown that both drugs administered at 5 mg/kg produced similar survival percentages and reductions of fungal burden. A slightly lower nephrotoxicity, associated with amphotericin B, was observed with AMB:DCH 1:1.5 than the one induced by the liposomal commercial formulation. However, AMB:DCH 1:1.5 reached higher AMB concentrations in lungs, which could represent a therapeutic advantage over liposomal commercial amphotericin B-based treatment of pulmonary aspergillosis. These results are encouraging to explore the usefulness of AMB:DCH 1:1.5 against this disease.

There is a limited understanding of the population pharmacokinetics (PK) and pharmacodynamics (PD) of amphotericin B deoxycholate (DAmB) for cryptococcal meningitis. A PK study was conducted in n = 42 patients receiving DAmB (1 mg/kg of body weight every 24 h [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 treatment of cryptococcal meningitis patients with DAmB monotherapy, and a meta-analysis was performed. The PK parameter means (standard deviations) were as follows: clearance, 0.03 (0.01) × weight + 0.67 (0.01) liters/h; volume, 0.82 (0.80) × weight + 1.76 (1.29) liters; first-order rate constant from central compartment to peripheral compartment, 5.36 (6.67) h-1; first-order rate constant from peripheral compartment to central compartment, 9.92 (12.27) h-1 The meta-analysis suggested that the DAmB dosage explained most of the heterogeneity in cerebrospinal fluid (CSF) sterility outcomes but not in mortality outcomes. Simulations of values corresponding to the area under concentration-time curve from h 144 to h 168 (AUC144-168) resulted in median (interquartile range) values of 5.83 mg · h/liter (4.66 to 8.55), 10.16 mg · h/liter (8.07 to 14.55), and 14.51 mg · h/liter (11.48 to 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 with clearance and volume. Interpatient PK variability is modest and unlikely to be responsible for variability in clinical outcomes. There is discordance between the impact that drug exposure has on CSF sterility and its impact on mortality outcomes, which may be due to cerebral pathology not reflected in CSF fungal burden, in addition to clinical variables.

This article summarizes the diagnosis and treatment of coccidioidal meningitis (CM) and its complications. An overview of current and prospective pharmacologic treatment options and monitoring parameters is provided. A consensus has not been reached regarding universally accepted therapeutic serum levels for azoles because of insufficient evidence. We describe the preferred therapeutic drug level ranges that our institution uses to monitor azole therapy.

Amphotericin B deoxycholate belongs to the polyene class of antifungals. It is also known by the name conventional amphotericin B and has been used for the treatment of invasive fungal infections for more than 50 years. It was first isolated as a natural product of a soil actinomycete.