In vitro activity of taurolidine against clinical Candida auris isolates: relevance to catheter-related bloodstream infections.

Candida auris is an evolving and concerning global threat. Of particular concern are bloodstream infections related to central venous catheters. We evaluated the activity of taurolidine, a broad-spectrum antimicrobial in catheter lock solutions, against 106 C. auris isolates. Taurolidine was highly active with a MIC50/MIC90 of 512/512 mg/L, over 20-fold lower than lock solution concentrations of ≥13,500 mg/L. Our data demonstrate a theoretical basis for taurolidine-based lock solutions for prevention of C. auris catheter-associated infections.

Postmarketing experience with Neutrolin® (taurolidine, heparin, calcium citrate) catheter lock solution in hemodialysis patients.

Catheter-related bloodstream infections (CRBSI) are major complications for patients with life-threatening conditions requiring chronic vascular catheterization. The wide range of etiologic microbes and the ongoing development of resistance to antimicrobials with specific mechanisms of action make this an appropriate target for applying a nonspecific antimicrobial therapeutic. Taurolidine hydrolyzes into two antimicrobial moieties, formaldehyde and methylene glycol, which react with microbial surfaces. Neutrolin® (taurolidine, heparin, calcium citrate) was recently introduced in Germany as an antimicrobial catheter lock solution. This postmarketing experience collected data on 201 patients at 20 centers from January 2014 through September 2016. Likely CRBSI was observed in 13 episodes in 47,118 days (0.2759 per 1000 days [0.1468, 0.4718]). Thrombosed catheter was observed in seven catheters in 47,118 days (0.1486 per 1000 days [0.0595, 0.3061]). No adverse drug reactions that led to the discontinuation of Neutrolin® use were reported. Two patients experienced occasional transient dysgeusia. Neutrolin®, when used in conjunction with guideline-based catheter care, showed reduction in the rate of both CRBSI and catheter thrombosis relative to recent historical controls.

DPI-289, a novel mixed delta opioid agonist / mu opioid antagonist (DAMA), has L-DOPA-sparing potential in Parkinson's disease.

L-DOPA-induced dyskinesia (LID) remains a significant problem in the management of Parkinson's disease (PD). In rodent and macaque models of PD, delta opioid receptor agonists have anti-parkinsonian actions while mu opioid antagonists can reduce the expression of LID. DPI-289 is a novel molecule with a unique combination of opioid receptor DAMA actions: delta agonist (Ki: 0.73 nM); mu antagonist (Ki: 12 nM). We demonstrated that DPI-289 has oral bioavailability and established its pharmacokinetic profile in both rat and primate. We hypothesised that these combined DAMA actions would provide an enhancement of L-DOPA effect without an associated increase in dyskinesia. In parkinsonian 6-OHDA lesioned rats and MPTP-lesioned macaques, DPI-289 provided anti-parkinsonian actions as monotherapy and an enhancement of L-DOPA benefit. Thus, acute administration of DPI-289 (3 mg/kg, p.o.) to 6-OHDA-lesioned rats produced a significant reduction in forelimb asymmetry (by 48%) that was maintained throughout the fifteen-day repeat-treatment period. Importantly, and in contrast to L-DOPA administration (6 mg/kg, i.p.), these benefits were not compromised by the development of abnormal involuntary movements. In the macaque, as monotherapy, DPI-289 (10 and 20 mg/kg) had significant, though incomplete, anti-parkinsonian actions lasting approximately 4 h. These benefits were not associated with dyskinesia. In fact, over the 6 h period of observation, DPI-289 (20 mg/kg) decreased parkinsonism by 19% and increased activity by 67% compared to vehicle treatment. By contrast, while high-dose L-DOPA (LDh) alone alleviated parkinsonism (for 3 h) this benefit was accompanied by significant dyskinesia that was disabling in nature. LDh provided a 50% reduction in parkinsonism over 6 h and 151% increase in activity. The combination of DPI-289 (20 mg/kg) and a low-dose of L-DOPA (LDl) provided anti-parkinsonian benefits greater than LDl alone without eliciting any significant dyskinesia. Treatment with LDl alone provided only transient statistically significant anti-parkinsonian benefit. However, the combination of LDl and DPI-289 reduced parkinsonism for 6 h (duration of monitoring), with parkinsonism being reduced by 35% and activity increased by 90% but with no increase in dyskinesia over that observed with LDl alone. Thus, DPI-289 has potential to improve the benefits of dopaminergic therapy in Parkinson's disease.

Potential for a pluripotent adult stem cell treatment for acute radiation sickness.

Accidental radiation exposure and the threat of deliberate radiation exposure have been in the news and are a public health concern. Experience with acute radiation sickness has been gathered from atomic blast survivors of Hiroshima and Nagasaki and from civilian nuclear accidents as well as experience gained during the development of radiation therapy for cancer. This paper reviews the medical treatment reports relevant to acute radiation sickness among the survivors of atomic weapons at Hiroshima and Nagasaki, among the victims of Chernobyl, and the two cases described so far from the Fukushima Dai-Ichi disaster. The data supporting the use of hematopoietic stem cell transplantation and the new efforts to expand stem cell populations ex vivo for infusion to treat bone marrow failure are reviewed. Hematopoietic stem cells derived from bone marrow or blood have a broad ability to repair and replace radiation induced damaged blood and immune cell production and may promote blood vessel formation and tissue repair. Additionally, a constituent of bone marrow-derived, adult pluripotent stem cells, very small embryonic like stem cells, are highly resistant to ionizing radiation and appear capable of regenerating radiation damaged tissue including skin, gut and lung.

Population pharmacokinetics of oxycodone in children 6 months to 7 years old.

Young children are often undertreated for pain. One barrier to effective pain treatment is understanding the pharmacokinetic behavior of analgesics in this age group. Oxycodone is a commonly prescribed opioid for severe pain, yet little is known about its pharmacokinetics in young children. This article used population pharmacokinetic modeling to synthesize pharmacokinetic data from several studies into a model. A single population model that described the observed pharmacokinetics was developed. The combined data were best described with a 2-compartment linear model with different first-order absorption rates depending on route of administration. Weight was found to significantly influence both clearance (CL) and volume of distribution (Vd). The following model adequately describes the population pharmacokinetic profile of oxycodone where absolute bioavailability (F) is estimated for each administration route: CL/F=55x(body weight/70)0.87; V/F=86x(body weight/70)1.16. The interindividual coefficients of variation in CL and Vd were 20.2 and 19.7%, respectively. This finding confirms that the allometric scaling using the above model explained most of the variability in exposure observed among children. This model confirms using a weight-based dose for oxycodone without adjustment for age between 6 months and 7 years and is valuable for evaluating dosing schedules and dosing routes.

Changes in fecal flora and comparative multiple-dose pharmacokinetics of ceftibuten, cefpodoxime proxetil and amoxycillin/clavulanate.

OBJECTIVE: To investigate changes in fecal flora and multiple-dose pharmacokinetics with the oral antibiotics ceftibuten 400 mg daily and cefpodoxime proxetil (CPX) 200 mg every 12 h, compared to amoxycillin/clavulanate 500/125 mg every 8 h during and following 1 week of medication. METHODS: In an open randomized triple crossover design, 18 (nine female, nine male) healthy volunteers received each drug for 7 days, followed by a 'washout' period of 4 weeks. Serum and urine levels of the substances were determined by bioassay, and for ceftibuten isomers by high-pressure liquid chromatography. Statistical analysis of quantitative aerobic and anaerobic cultures of feces was performed, and beta-lactamase activity was determined. RESULTS: Ceftibuten showed a mean Cmax of 18.9 (SD 3.0) mg/L, a terminal half-life of 2.89 h, and an AUCtot of 100 (21.8) mg.h/L; protein binding was 63.7 (5.1)%, and accumulation was marginal. Cefpodoxime proxetil had a Cmax of 1.92 (0.61) mg/L, a terminal half-life of 1.97 (0.42) h and an AUCtot of 10.8 (3.3) mg.h/L; no accumulation was seen. Amoxycillin and clavulanate had Cmax values of 7.15 (2.16) mg/L and 3.39 (1.31) mg/L, terminal half-life values of 1.03 (0.15) h and 0.93 (0.17) h, AUCtot values of 20.0 (4.2) mg.h/L and 8.87 (3.10) mg.h/L, and there was no accumulation. Statistical analysis for ech microorganism in fecal samples showed significant differences between amoxycillin/clavulanate and the two third-generation cephalosporins, but virtually no differences between ceftibuten and cefpodoxime proxetil. Eleven of 12 volunteers reported loose stools (days 2-7, mean duration 4.4 (SD 2.7) days) with amoxycillin/clavulanate, but nobody during ceftibuten administration and one volunteer during cefpodoxime proxetil administration. CONCLUSIONS: Ceftibuten showed excellent and cefpodoxime favorable pharmacokinetic properties, with significantly less pronounced fecal flora changes and intestinal side effects compared to amoxycillin/clavulanate. The multiple crossover design allows powerful microbiological statistical analysis and pharmacokinetic parameter comparisons.