Population pharmacokinetics of ciprofloxacin in newborns with early onset neonatal sepsis and suspected meningitis.

BACKGROUND: Neonatal Sepsis accounts for significant proportion of neonatal mortality globally. Ciprofloxacin can be used as an effective antimicrobial against common causative agents of neonatal sepsis. However, there is only limited information about its pharmacokinetic distribution in plasma and Cerebrospinal fluid (CSF) of neonates. METHODS: Plasma and CSF samples were taken using a sparse sampling technique from neonates who received at least one dose of intravenous ciprofloxacin. Ciprofloxacin levels were analysed using high-performance liquid chromatography (HPLC). Population pharmacokinetic analysis was conducted using a non-linear mixed-effects modelling using Pumas® (Pharmaceutical Modelling and Simulation) package (Version 2.0). RESULTS: 53 neonates were enroled in the study of whom; 9 (17%) had meningitis. The median concentration of ciprofloxacin in CSF was 1.4 (0.94-2.06) ug/ml and plasma was 2.94 (1.8-5.0) ug/ml. A one-compartment model with first-order elimination fitted the data. Body weight was found to be a significant covariate on volume of distribution (Vd). Simulations based on the final model suggest that dose of 10 mg/kg, intravenous b.d may not be able to achieve the desirable indices. CONCLUSIONS: One compartment model with weight as a covariate explained the available data. Further studies with modified sampling strategy, larger sample size and variable dose levels are needed.

Bio-evaluation of poly(lactic-co-glycolic) acid nanoparticles loaded with radiolabelled rifampicin.

AIMS: The poly(lactic-co-glycolic) acid (PLGA) nanoparticles of tubercular drugs have been demonstrated to have a sustained release profile over 7 days. There is no information on the location or mode of release of these nanoparticles in living systems. Therefore, we have planned the study to explore the pharmacokinetics and biodistribution of PLGA rifampicin nanoparticles in healthy human volunteers. We aim to study the distribution pattern of PLGA-loaded nano-formulation of radiolabelled rifampicin in humans. METHODS: Rifampicin was labelled with 99m Tc by indirect method and nanoparticles were prepared by a single emulsion evaporation method. To investigate the pharmacokinetics and biodistribution of nanoparticles, a single dose of 450 mg of rifampicin was administered orally to healthy human volunteers divided into two different groups. RESULTS: Following a single oral dosage of the rifampicin nanoformulation, the pharmacokinetic (PK) parameters were significantly different between the nanoparticle and conventional groups: area under the concentration-time curve (AUC = 113.8 vs. 58.6; P < .001), mean residence time (MRT = 16.2 vs. 5.8; P < .01) and elimination rate constant (Ke = 0.04 vs. 0.10; P < .05). Also, Single-photon emission computed tomography/computed tomography (SPECT/CT) images revealed biodistribution of nanoparticles in the distal portions of the intestine, which is consistent with our dosimetry analysis. CONCLUSIONS: Significant difference in PK parameters and biodistribution of nanoparticles in spleen and lymph nodes with maximum deposition were observed in the large intestine. The nanoparticle distribution pattern may be advantageous for the treatment of intestinal or lymph node tuberculosis (TB) and has the potential to result in a lower dose of rifampicin nanoformulation for the treatment of pulmonary TB.

Antibiotic Prophylaxis for Orthopaedic Implant Removal: What Does the Evidence Say?

Orthopaedic implant removal is considered a sterile procedure, but the current literature suggests it is associated with around a 20% Surgical Site Infection (SSI) rate. The use of antibiotic prophylaxis is still ambiguous and contentious. Taking into consideration this issue we conducted a meta-analysis for the use of antibiotic prophylaxis in orthopaedic implant removal surgery. OBJECTIVES: To determine whether or not antibiotic prophylaxis benefits orthopaedic implant removal surgeries. METHODS: Electronic and printed sources were searched up to February 2021 for randomised controlled trials (RCTs) using antibiotic prophylaxis and a control group. Data from eligible studies were pooled for the following outcomes: overall, superficial, and deep surgical site infection (SSI). Pooled odds ratios with a 95% confidence interval (CI) were calculated using Mantel Haenszel fixed-effect model preferentially. RESULTS: Two studies, including 766 patients were included in this meta-analysis. Heterogeneity was not statistically significant between the studies. There was no significant difference in the incidence of overall SSI in cefazolin and normal saline (NS) groups (Pooled OR 0.79; 95% CI 0.53- 1.17). In subgroup analysis, antibiotic prophylaxis showed statistically significant improvement for deep SSI (Pooled OR 0.20; 95% CI 0.06-0.70). CONCLUSION: Overall incidence of SSI is not reduced after the administration of antibiotic prophylaxis one hour before removal of orthopaedic implants.

A study to explore the appropriateness of dosing regimen of vancomycin in critically ill patients in a tertiary care unit of India.

Introduction: Vancomycin is used in proven or suspected MRSA and MRE infections. An AUC/MIC ratio of ≥400 is the current accepted critical PK/PD"efficacy" target of vancomycin activity. The present study was conducted to ascertain the appropriateness of practice of current dosage regimen of vancomycin (1 g BD) based on population pharmacokinetic approach. Methods: A single-center prospective study with the ICU setting of a tertiary care center was conducted. A total of 15 adult patients with sepsis treated with vancomycin were included over 15 months from May 2019 to July 2020. Blood samples were obtained at 5, 10, and 30 minutes and thereafter at 2 and 6 hours following the completion of the vancomycin infusion. The data obtained from HPLC estimation was analyzed using a population pharmacokinetic approach with NLME, Phoenix 8.3.2.166. The pharmacokinetic model was based on covariates such as bodyweight and urinary creatinine clearance to predict drug concentrations. Results: A total of 83 vancomycin blood samples were analyzed. The mean AUC0-last and AUC0-∞ in patients who improved and died were (AUC(0-last)=293 (152.97); AUC(0-∞)=535.14 (353.67) and (AUC(0-last)=137.19 (51.37); AUC(0-∞)=582.12 (1036.09) respectively, the difference between the two outcome groups was not statistically significant (p=0.104). The pharmacokinetic model was best described by a two-compartment linear model. The goodness-of-fit plots showed that the final covariate pharmacokinetic model (having bodyweight and urinary creatinine clearance) adequately described the observed vancomycin concentrations. Conclusions: Based on the finding of the study it was concluded that 1 g BD dosing of vancomycin is inappropriate. Including covariates such as urinary creatinine clearance and weight in the pharmacokinetic model helped predict drug concentrations more accurately. However, further studies are required to demonstrate efficacy regarding applying this strategy.

Assessment of Appropriateness of Antimicrobial Therapy in Resource-Constrained Settings: Development and Piloting of a Novel Tool-AmRAT.

Inappropriate antimicrobial prescribing is considered to be the leading cause of high burden of antimicrobial resistance (AMR) in resource-constrained lower- and middle-income countries. Under its global action plan, the World Health Organization has envisaged tackling the AMR threat through promotion of rational antibiotic use among prescribers. Given the lack of consensus definitions and other associated challenges, we sought to devise and validate an Antimicrobial Rationality Assessment Tool-AmRAT-for standardizing the assessment of appropriateness of antimicrobial prescribing. A consensus algorithm was developed by a multidisciplinary team consisting of intensivists, internal medicine practitioners, clinical pharmacologists, and infectious disease experts. The tool was piloted by 10 raters belonging to three groups of antimicrobial stewardship (AMS) personnel: Master of Pharmacology (M.Sc.) (n = 3, group A), Doctor of Medicine (MD) residents (n = 3, group B), and DM residents in clinical pharmacology (n = 4, group C) using retrospective patient data from 30 audit and feedback forms collected as part of an existing AMS program. Percentage agreement and the kappa (κ) coefficients were used to measure inter-rater agreements amongst themselves and with expert opinion. Sensitivity and specificity estimates were analyzed comparing their assessments against the gold standard. For the overall assessment of rationality, the mean percent agreement with experts was 76.7% for group A, 68.9% for group B, and 77.5% for group C. The kappa values indicated moderate agreement for all raters in group A (κ 0.47-0.57), and fair to moderate in group B (κ 0.22-0.46) as well as group C (κ 0.37-0.60). Sensitivity and specificity for the same were 80% and 68.6%, respectively. Though evaluated by raters with diverse educational background and variable AMS experience in this pilot study, our tool demonstrated high percent agreement and good sensitivity and specificity, assuring confidence in its utility for assessing appropriateness of antimicrobial prescriptions in resource-constrained healthcare environments.