Low but sufficient anidulafungin exposure in critically ill patients.

The efficacy of anidulafungin is driven by the area under the concentration-time curve (AUC)/MIC ratio. Patients in intensive care may be at risk for underexposure. In critically ill patients with an invasive Candida infection, the anidulafungin exposure and a possible correlation with disease severity or plasma protein levels were explored. Concentration-time curves were therefore obtained at steady state. Anidulafungin concentrations were measured with a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. The MIC values of the Candida species were determined with the Etest. The target AUC/MIC ratio was based on European Committee on Antimicrobial Susceptibility Testing (EUCAST) data. Twenty patients were included. The patients received a maintenance dose of 100 mg once daily after a loading dose of 200 mg on the first day. The mean (±standard deviation) AUC, maximum concentration of drug in plasma (Cmax), and minimum concentration of drug in plasma (Cmin) were 69.8 ± 24.1 mg · h/liter, 4.7 ± 1.4 mg/liter, and 2.2 ± 0.8 mg/liter, respectively. The MIC values of all cultured Candida species were below the EUCAST MIC breakpoints. The exposure to anidulafungin in relation to the MIC that was determined appeared sufficient in all patients. The anidulafungin exposure was low in our critically ill patients. However, combined with the low MICs of the isolated Candida strains, the lower exposure observed in comparison to the exposure in the general patient population resulted in favorable AUC/MIC ratios, based on EUCAST data. No correlation was observed between anidulafungin exposure and disease severity or plasma protein concentrations. In patients with less-susceptible Candida albicans or glabrata strains, we recommend considering determining the anidulafungin exposure to ensure adequate exposure. (This trial has been registered at ClinicalTrials.gov under registration no. NCT01047267.).

Effect of preventive supplementation with zinc and other micronutrients on non-malarial morbidity in Tanzanian pre-school children: a randomized trial.

BACKGROUND: The efficacy of preventive zinc supplementation against diarrhea and respiratory illness may depend on simultaneous supplementation with other micronutrients. We aimed to assess the effect of supplementation with zinc and multiple micronutrients on diarrhea and other causes of non-malarial morbidity. METHODS AND FINDINGS: Rural Tanzanian children (n = 612) aged 6-60 months and with height-for-age z-score < -1.5 SD were randomized to daily supplementation with zinc (10 mg) alone, multi-nutrients without zinc, multi-nutrients with zinc, or placebo. Children were followed for an average of 45 weeks. During follow-up, we recorded morbidity episodes. We found no evidence that concurrent supplementation with multi-nutrients influenced the magnitude of the effect of zinc on rates of diarrhea, respiratory illness, fever without localizing signs, or other illness (guardian-reported illness with symptoms involving skin, ears, eyes and abscesses, but excluding trauma or burns). Zinc supplementation reduced the hazard rate of diarrhea by 24% (4%-40%). By contrast, multi-nutrients seemed to increase this rate (HR; 95% CI: 1.19; 0.94-1.50), particularly in children with asymptomatic Giardia infection at baseline (2.03; 1.24-3.32). Zinc also protected against episodes of fever without localizing signs (0.75; 0.57-0.96), but we found no evidence that it reduced the overall number of clinic visits. CONCLUSIONS: We found no evidence that the efficacy of zinc supplements in reducing diarrhea rates is enhanced by concurrent supplementation with other micronutrients. By reducing rates of fever without localizing signs, supplementation with zinc may reduce inappropriate drug use with anti-malarial medications and antibiotics. TRIAL REGISTRATION: ClinicalTrials.gov NCT00623857.

Effect of supplementation with zinc and other micronutrients on malaria in Tanzanian children: a randomised trial.

BACKGROUND: It is uncertain to what extent oral supplementation with zinc can reduce episodes of malaria in endemic areas. Protection may depend on other nutrients. We measured the effect of supplementation with zinc and other nutrients on malaria rates. METHODS AND FINDINGS: In a 2×2 factorial trial, 612 rural Tanzanian children aged 6-60 months in an area with intense malaria transmission and with height-for-age z-score≤-1.5 SD were randomized to receive daily oral supplementation with either zinc alone (10 mg), multi-nutrients without zinc, multi-nutrients with zinc, or placebo. Intervention group was indicated by colour code, but neither participants, researchers, nor field staff knew who received what intervention. Those with Plasmodium infection at baseline were treated with artemether-lumefantrine. The primary outcome, an episode of malaria, was assessed among children reported sick at a primary care clinic, and pre-defined as current Plasmodium infection with an inflammatory response, shown by axillary temperature ≥37.5°C or whole blood C-reactive protein concentration ≥ 8 mg/L. Nutritional indicators were assessed at baseline and at 251 days (median; 95% reference range: 191-296 days). In the primary intention-to-treat analysis, we adjusted for pre-specified baseline factors, using Cox regression models that accounted for multiple episodes per child. 592 children completed the study. The primary analysis included 1,572 malaria episodes during 526 child-years of observation (median follow-up: 331 days). Malaria incidence in groups receiving zinc, multi-nutrients without zinc, multi-nutrients with zinc and placebo was 2.89/child-year, 2.95/child-year, 3.26/child-year, and 2.87/child-year, respectively. There was no evidence that multi-nutrients influenced the effect of zinc (or vice versa). Neither zinc nor multi-nutrients influenced malaria rates (marginal analysis; adjusted HR, 95% CI: 1.04, 0.93-1.18 and 1.10, 0.97-1.24 respectively). The prevalence of zinc deficiency (plasma zinc concentration <9.9 µmol/L) was high at baseline (67% overall; 60% in those without inflammation) and strongly reduced by zinc supplementation. CONCLUSIONS: We found no evidence from this trial that zinc supplementation protected against malaria. TRIAL REGISTRATION: ClinicalTrials.gov NCT00623857

Limited-sampling strategies for therapeutic drug monitoring of moxifloxacin in patients with tuberculosis.

BACKGROUND: Moxifloxacin (MFX) is a potent drug for multidrug resistant tuberculosis(TB) treatment and is also useful if first-line agents are not tolerated. Therapeutic drug monitoring may help to prevent treatment failure. Obtaining a full concentration-time curve of MFX for therapeutic drug monitoring is not feasible in most settings. Developing a limited-sampling strategy based on population pharmacokinetics (PK) may help to overcome this problem. METHODS: Steady-state plasma concentrations after the administration of 400 mg of MFX once daily were determined in 21 patients with TB, using a validated liquid chromatography-tandem mass spectrometry method. A one-compartment population model was generated and crossvalidated. Monte Carlo data simulation (n=1000) was used to calculate limited-sampling strategies. The correlation between predicted MFX AUC0-24h (area under the concentration-time curve 0 to 24 hours) and observed AUC0-24h was investigated by Bland-Altman analysis. Finally, the predictive performance of the final model was tested prospectively using MFX profiles from patients with TB receiving 400, 600, or 800 mg once daily. RESULTS: Median minimum inhibitory concentration of Mycobacterium tuberculosis isolates was 0.25 mg/L (interquartile range: 0.25-0.5 mg/L). The geometric mean AUC0-24h was 24.5 mg·h/L (range: 8.5-72.2 mg·h/L), which resulted in a geometric mean AUC0-24h/minimum inhibitory concentration ratio of 72 (range: 21-321). PK analysis, based on PK profiles of 400 mg of MFX once daily, resulted in a crossvalidated population PK model with the following parameters: apparent clearance (Cl) 18.5±8.6 L/h per 1.85 m, Vd 3.0±0.7 L/kg corrected lean body mass, Ka 1.15±1.16 h, and F was fixed at 1. After the Monte Carlo simulation, the best predicting strategy for MFX AUC0-24h for practical use was based on MFX concentrations 4 and 14 hours postdosing (r=0.90, prediction bias=-1.5%, and root mean square error=15%). CONCLUSIONS: MFX AUC0-24h in patients with TB can be predicted with acceptable accuracy for clinical management, using limited sampling. AUC0-24h prediction based on 2 samples, 4 and 14 hours postdose, can be used to individualize treatment.