Comparing clinical outcomes of piperacillin-tazobactam administration and dosage strategies in critically ill adult patients: a systematic review and meta-analysis

Exposure levels and target attainment of piperacillin/tazobactam in adult patients admitted to the intensive care unit: a prospective observational study

PURPOSE

The objective of this study was to evaluate the exposure and the pharmacodynamic target attainment of piperacillin/tazobactam (PTZ) in adult critically ill patients.

METHODS

We conducted a prospective observational study in the intensive care unit (ICU) of the Hôpital du Sacré-Cœur de Montréal (a Level I trauma centre in Montreal, QC, Canada) between January 2021 and June 2022. We included patients aged 18 yr or older admitted to the ICU who received PTZ by intravenous administration. Demographic and clinical characteristics were collected, and clinical scores were calculated. On study day 1 of antimicrobial therapy, three blood samples were collected at the following timepoints: one hour after PTZ dose administration and at the middle and at the end of the dosing interval. The sampling schedule was repeated on days 4 and 7 of therapy if possible. Samples were analyzed by ultra-high performance liquid chromatography with diode array detector to determine the total piperacillin concentration. Middle- and end-of-interval concentrations were used for target attainment analyses, and were defined as a concentration above the minimal inhibitory concentration of 16 mg·L-1, corresponding to the breakpoint of Enterobacteriaceae and Pseudomonas aeruginosa.

RESULTS

Forty-three patients were recruited and 202 blood samples were analyzed. The most prevalent dose was 3/0.375 g every six hours (n = 50/73 doses administered, 68%) with a 30-min infusion. We observed marked variability over the three sampling timepoints, and the median [interquartile range] piperacillin concentrations at peak, middle of interval, and end of interval were 109.4 [74.0-152.3], 59.3 [21.1-74.4], and 25.3 [6.8-44.6] mg·L-1, respectively. When assessing target attainment, 37% of patients did not reach the efficacy target of a trough concentration of 16 mg·L-1. The majority of patients who were underexposed were patients with normal to augmented renal clearance.

CONCLUSION

In this prospective observational study of adult ICU patients receiving intravenous PTZ, a large proportion had subtherapeutic concentrations of piperacillin. This was most notable in patients with normal to augmented renal clearance. More aggressive dosage regimens may be required for this subpopulation to ensure attainment of efficacy targets.

Drug Utilization Evaluation and Impact of Pharmacist Interventions on Optimization of Piperacillin/Tazobactam Use: A Retrospective Analysis and Prospective Audit

(1) Background: Piperacillin/tazobactam is a broad-spectrum antimicrobial encompassing most Gram-positive and Gram-negative aerobic and anaerobic bacteria. The inappropriate use of such broad-spectrum antibiotics is an important contributor to the rising rates of antimicrobial drug resistance worldwide. Drug utilization evaluation studies and pharmacists' interventions are vital to assess, develop, and promote the rational use of antibiotics. This drug utilization study aimed to evaluate the current utilization practice of piperacillin/tazobactam in a hospital setting and assess the impact of pharmacist intervention in improving its appropriate use. (2) Methodology: In this study, we used a retrospective cohort and a prospective cohort, a cross-sectional, observational method. It included a retrospective (Cycle A/pre-intervention-CycA) phase followed by an educational interventional phase conducted by the pharmacists. During the 2 months of educational intervention, pharmacists used several methods, including workshops, lectures, oral presentations, and the development and reinforcement of clinical pathways to promote the judicious use of piperacillin/tazobactam. This was followed by a prospective (Cycle B/post-intervention-CycB) phase to improve piperacillin/tazobactam usage appropriateness. The appropriateness criteria for this drug utilization evaluation were established based on antimicrobial guidelines, the published literature, the institutional antibiogram, consultation from the antimicrobial stewardship committee, and the product monograph (Tazocin). The appropriateness of CycA and CycB patients was compared using the measurable elements, including indication and dose based on renal function, timely order for cultures, de-escalation, and use of extended infusion protocol. (3) Results: The study population comprised 100 patients in both CycA and CycB. The mean age of the patients was 66.28 ± 16.15 and 67.35 ± 17.98, and the ratios of men to women were found to be 49:51 and 61:39 in CycA and CycB, respectively. It was observed that inappropriate usage was high in CycA patients, and the appropriateness was improved in CycB patients. A total of 31% of inappropriate empirical broad-spectrum use was found in CycA, and it was reduced to 12% in CycB patients. The transition of appropriateness was observed in all measurable criteria, which includes the optimized dose according to the renal function (CycA = 49% to CycB = 94%), timely bacterial culture orders (CycA = 47% to CycB = 74%), prompt de-escalation (CycA = 31% to CycB = 53%), and adherence to extended infusion institutional guidelines (CycA = 34% to CycB = 86%). (4) Conclusions: The study highlighted important aspects of inappropriate piperacillin/tazobactam use. This can be considerably improved by proper education and timely interventions based on the pharmacists' vigilant approach. The study results emphasized the need for surveillance of piperacillin/tazobactam usage by conducting similar drug utilization evaluations and practice to improve quality and safety in healthcare organizations globally.

Clinical efficacy and safety of prolonged versus intermittent administration of antipseudomonal beta-lactam antibiotics in adults with severe acute infections: A meta-analysis of randomized controlled trials

INTRODUCTION

In order to compare the clinical efficacy and safety of prolonged versus intermittent antipseudomonal beta-lactam antibiotic infusion for the treatment of severe acute infections in adult patients, a meta-analysis of randomized controlled trials (RCTs) was performed.

METHODS

We systematically searched MEDLINE and Cochrane Library databases until December 2022. The outcomes were all-cause mortality, clinical success, microbiological eradication and adverse events. The pooled risk ratios (RR) were estimated by the fixed or random effect methods according to heterogeneity statistics. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was used to evaluate the certainty of evidence for each outcome.

RESULTS

Twenty eligible RCTs with 2081 participants were included in the meta-analysis. The risk of all-cause mortality was significantly lower in the prolonged infusion group than in the intermittent infusion group (RR 0.77, 95% confidence interval [CI] 0.63-0.95, p = 0.01, I² = 0%; moderate certainty). Treatment with prolonged infusion showed significant benefit in clinical success (RR 1.09, 95% CI 1.02-1.17, p = 0.008, I² = 19%; moderate certainty). There were no significant differences in microbiological eradication (RR 1.12, 95% CI 0.99-1.28, p = 0.07, I² = 49%; low certainty), any adverse events (RR 0.96, 95% CI 0.86-1.08, p = 0.50, I² = 27%; moderate certainty) and serious adverse events (RR 0.99, 95%CI 0.70-1.39 p = 0.95, I² = 0%; low certainty).

CONCLUSIONS

Prolonged antipseudomonal beta-lactam infusion probably decreases all-cause mortality. Additionally, it probably increases clinical success in adults with severe acute infections. This infusion strategy may result in little to no difference in microbiological eradication and is probably not associated with a rise in any adverse events.The evidence suggests that prolonged infusion may not increase serious adverse events.

Pathogen-based target attainment of optimized continuous infusion dosing regimens of piperacillin-tazobactam and meropenem in surgical ICU patients: a prospective single center observational study

BACKGROUND

Several studies have indicated that commonly used piperacillin-tazobactam (TZP) and meropenem (MEM) dosing regimens lead to suboptimal plasma concentrations for a range of pharmacokinetic/pharmacodynamic (PK/PD) targets in intensive care unit (ICU) patients. These targets are often based on a hypothetical worst-case scenario, possibly overestimating the percentage of suboptimal concentrations. We aimed to evaluate the pathogen-based clinically relevant target attainment (CRTA) and therapeutic range attainment (TRA) of optimized continuous infusion dosing regimens of TZP and MEM in surgical ICU patients.

METHODS

A single center prospective observational study was conducted between March 2016 and April 2019. Free plasma concentrations were calculated by correcting total plasma concentrations, determined on remnants of blood gas samples by ultra-performance liquid chromatography with tandem mass spectrometry, for their protein binding. Break points (BP) of identified pathogens were derived from epidemiological cut-off values. CRTA was defined as a corrected measured total serum concentration above the BP and calculated for increasing BP multiplications up to 6 × BP. The upper limit of the therapeutic range was set at 157.2 mg/L for TZP and 45 mg/L for MEM. As a worst-case scenario, a BP of 16 mg/L for TZP and 2 mg/L for MEM was used.

RESULTS

781 unique patients were included with 1036 distinctive beta-lactam antimicrobial prescriptions (731 TZP, 305 MEM) for 1003 unique infections/prophylactic regimens (750 TZP, 323 MEM). 2810 samples were available (1892 TZP, 918 MEM). The median corrected plasma concentration for TZP was 86.4 mg/L [IQR 56.2-148] and 16.2 mg/L [10.2-25.5] for MEM. CRTA and TRA was consistently higher for the pathogen-based scenario than for the worst-case scenario, but nonetheless, a substantial proportion of samples did not attain commonly used PK/PD targets.

CONCLUSION

Despite these pathogen-based data demonstrating that CRTA and TRA is higher than in the often-used theoretical worst-case scenario, a substantial proportion of samples did not attain commonly used PK/PD targets when using optimised continuous infusion dosing regimens. Therefore, more dosing optimization research seems warranted. At the same time, a 'pathogen-based analysis' approach might prove to be more sensible than a worst-case scenario approach when evaluating target attainment and linked clinical outcomes.

Correlation between antibiotic consumption and resistance of Pseudomonas aeruginosa in a teaching hospital implementing an antimicrobial stewardship program: A longitudinal observational study

BACKGROUND/PURPOSE

The rapid emergence of Pseudomonas aeruginosa resistance made selecting antibiotics more challenge. Antimicrobial stewardship programs (ASPs) are urging to implant to control the P. aeruginosa resistance. The purpose of this study is to evaluate the relationship between antimicrobial consumption and P. aeruginosa resistance, the impact of ASPs implemented during the 14-year study period.

METHODS

A total 14,852 P. aeruginosa isolates were included in our study. The resistant rate and antimicrobial consumption were investigated every six months. Linear regression analysis was conducted to examine the trends in antibiotics consumption and antimicrobial resistance over time. The relationship between P. aeruginosa resistance and antimicrobial consumption were using Pearson correlation coefficient to analysis. The trend of resistance before and after ASPs implanted is evaluated by segment regression analysis.

RESULTS

P. aeruginosa resistance to ceftazidime, gentamicin, amikacin, ciprofloxacin and levofloxacin significantly decreased during the study period; piperacillin/tazobactam (PTZ), cefepime, imipenem/cilastatin and meropenem remained stable. The P. aeruginosa resistance to ciprofloxacin and levofloxacin increasing initial then decreased after strictly controlled the use of levofloxacin since 2007. As the first choice antibiotic to treat P. aeruginosa, the consumption and resistance to PTZ increase yearly and resistance became stable since extended-infusion therapy policy implant in 2009.

CONCLUSION

Our ASP intervention strategy, which included extended infusion of PTZ and restrict use of levofloxacin, may be used to control antimicrobial resistance of P. aeruginosa in medical practice.

Piperacillin Steady State Concentrations in Target Tissues Relevant for PJI Treatment—A Randomized Porcine Microdialysis Study Comparing Continuous Infusion with Intermittent Short-Term Infusion

(1) Introduction: Piperacillin is a common antibiotic choice in the treatment of periprosthetic joint infections (PJI) caused by Pseudomonas aeruginosa. The aim of this study was to assess and compare the time with free piperacillin concentration above the minimum inhibitory concentration (fT > MIC) at steady state in target tissues relevant for PJI treatment following continuous and intermittent short-term infusion. (2) Methods: 16 pigs were randomized to receive either continuous or intermittent short-term infusion of piperacillin. Steady state piperacillin concentrations were assessed using microdialysis in tibial cortical bone, tibial cancellous bone, synovial fluid of the knee joint, and subcutaneous tissue. MIC-targets of 4, 8, 16, and 64 mg/L were applied. Plasma samples were obtained as reference. (3) Results: Continuous infusion resulted in longer fT > MIC for MIC targets of 4 mg/L and 8 mg/L compared to intermittent short-term infusion in all compartments with the exception of tibial cortical bone. For the MIC-target of 16 mg/L, continuous infusion resulted in a longer fT > MIC in all compartments except for the bone compartments. No differences between groups were seen when applying a MIC-target of 64 mg/L. (4) Conclusions: An aggressive dosing strategy may be necessary to obtain sufficient piperacillin concentrations in all bone compartments, particularly if more aggressive targets are applied. Based on the present study, continuous infusion should be considered in the treatment of PJI.

Impact of extended-infusion piperacillin-tazobactam in a Canadian community hospital

BACKGROUND

Studies have demonstrated improved clinical outcomes with extended infusion (EI) piperacillin/tazobactam (TZP) compared to standard infusion (SI). However, there is less evidence on its benefits in noncritically-ill patients. Hospital-wide EI TZP was implemented at our site on February 21, 2012. Our objectives were to compare clinical, safety and economic outcomes between EI and SI TZP.

METHODS

A retrospective cohort study of all adult patients who received EI TZP (3.375 g IV q8h infused over 4 hours and SI TZP for ≥ 48 hours during 3 years pre-and postimplementation was conducted. The primary study outcome was 14-day mortality while secondary outcomes included length of hospital stay (LOS), nursing plus pharmacy cost, occurrence of Clostridioides difficile infection, readmission within 30 days and change in Pseudomonas aeruginosa minimum inhibitory concentration (MIC) distribution for TZP. The primary outcome and binary secondary outcomes were analyzed using a logistic regression model. LOS was examined using time to event analysis. Cost was examined using linear regression modelling.

RESULTS

Overall, 2034 patients received EI TZP and 1364 patients received SI TZP. EI TZP was associated with lower odds of mortality (OR 0.76, 95% CI 0.63-0.91), lower odds of C. difficile infection (OR 0.59, 95% CI 0.41-0.84) and 8% lower cost (estimate 0.92, 95% CI 0.87-0.98) compared to SI TZP.

CONCLUSIONS

Hospital-wide implementation of EI TZP was associated with lower odds of 14-day mortality and incidence of C. difficile infection with cost savings at our institution.

Beta-lactam exposure and safety in intermittent or continuous infusion in critically ill children: an observational monocenter study

The aim of this study was to assess the pharmacokinetic (PK) exposure and clinical toxicity for three beta-lactams: cefotaxime, piperacillin/tazobactam, and meropenem, depending on two lengths of infusion: continuous and intermittent, in critically ill children. This single center observational prospective study was conducted in a pediatric intensive care unit. All hospitalized children who had one measured plasma concentration of the investigated antibiotics were included. Plasma antibiotic concentrations were interpreted by a pharmacologist, using a Bayesian approach based on previously published population pharmacokinetic models in critically ill children. Exposure was considered optimal, low, or high according to the PK target 100% fT_{> 4 × MIC} and a trough concentration below the toxic concentration (50 mg.L^-1 for cefotaxime, 150 mg.L^-1 for piperacillin, and 44 mg.L^-1 for meropenem). Between May 2019 and January 2020, 80 patients were included and received 106 antibiotic courses: 74 (70%) were administered in intermittent infusion (II) and 32 (30%) in continuous infusion (CI). Compared to II, CI provided more optimal PK exposure (n = 22/32, 69% for CI versus n = 35/74, 47% for II, OR 1.2, 95%CI 1.01-1.5, p = 0.04), less underexposure (n = 4/32, 13% for CI versus n = 36/74, 49% for II, OR 0.7, 95%CI 0.6-0.84, p < 0.001), and more overexposure (n = 6/32, 19% for CI versus n = 3/74, 4% for II, OR 1.2, 95%CI 1.03-1.3, p = 0.01). Five adverse events have been reported during the study period, although none has been attributed to beta-lactam treatment.

CONCLUSION

CI provided a higher probability to attain an optimal PK target compared to II, but also a higher risk for overexposure. Regular therapeutic drug monitoring is recommended in critically ill children receiving beta-lactams, regardless of the length of infusion.

WHAT IS KNOWN

• Since beta-lactams are time-dependent antibiotics, the probability to attain the pharmacokinetic target is higher with continuous infusion compared to that with intermittent infusion. • In daily practice, continuous or extended infusions are rarely used despite recent guidelines, and toxicity is hardly reported.

WHAT IS NEW

• Continuous infusion provided a higher probability to attain an optimal pharmacokinetic target compared to intermittent infusion, but also a higher risk of overexposure. • Regular therapeutic drug monitoring is recommended in critically ill children receiving beta-lactams, regardless of the length of infusion.

Extended infusion of piperacillin-tazobactam versus intermittent infusion in critically ill egyptian patients: a cost-effectiveness study

Extended infusion of piperacillin/tazobactam over 4 h has been proposed as an alternate mode of administration to the 30-min intermittent infusion to optimize treatment effects in patients with gram-negative bacterial infections. The study aimed to evaluate the extended infusion regimen of piperacillin/tazobactam in standings of efficacy, safety, and cost to the intermittent one in the treatment of gram-negative bacterial infections. A prospective randomized comparative study was performed on 53 patients, 27 in the intermittent infusion group and 26 in the extended infusion group. The primary outcome was the mean number of days to clinical success and the percentage of patients who were clinically cured after treatment. The secondary outcomes included mortality, readmission within 30-days, and cost-effectiveness analysis based on the mean number of days to clinical success. The clinical success rate was comparable in the two groups. Days on extended infusion were significantly lower than intermittent infusion (5.7 vs 8.9 days, respectively, p = 0.0001) as well as days to clinical success (4.6 vs 8.5 days, respectively, p = 0.026). The extended infusion was superior to the intermittent infusion regarding cost-effectiveness ratio ($1835.41 and $1914.09/expected success, respectively). The more cost-effective regimen was the extended infusion. Both regimens had comparable clinical and microbiological outcomes.

Optimizing antibiotic therapies to reduce the risk of bacterial resistance

The incidence of infections caused by bacteria that are resistant to antibiotics is constantly increasing. In Europe alone, it has been estimated that each year about 33'000 deaths are attributable to such infections. One important driver of antimicrobial resistance is the use and abuse of antibiotics in human medicine. Inappropriate prescribing of antibiotics is still very frequent: up to 50% of all antimicrobials prescribed in humans might be unnecessary and several studies show that at least 50% of antibiotic treatments are inadequate, depending on the setting. Possible strategies to optimize antibiotic use in everyday clinical practice and to reduce the risk of inducing bacterial resistance include: the implementation of rapid microbiological diagnostics for identification and antimicrobial susceptibility testing, the use of inflammation markers to guide initiation and duration of therapies, the reduction of standard durations of antibiotic courses, the individualization of antibiotic therapies and dosing considering pharmacokinetics/pharmacodynamics targets, and avoiding antibiotic classes carrying a higher risk for induction of bacterial resistance. Importantly, measures to improve antibiotic prescribing and antibiotic stewardship programs should focus on facilitating clinical reasoning and improving prescribing environment in order to remove any barriers to good prescribing.

Treatment of ventilator-associated pneumonia due to carbapenem-resistant Gram-negative bacteria with novel agents: a contemporary, multidisciplinary ESGCIP perspective

INTRODUCTION

: In the past 15 years, treatment of VAP caused by carbapenem-resistant Gram-negative bacteria (CR-GNB) has represented an intricate challenge for clinicians.

AREAS COVERED

In this perspective article, we discuss the available clinical data about novel agents for the treatment of CR-GNB VAP, together with general PK/PD principles for the treatment of VAP, in the attempt to provide some suggestions for optimizing antimicrobial therapy of CR-GNB VAP in the daily clinical practice.

EXPERT OPINION

Recently, novel BL and BL/BLI combinations have become available that have shown potent in vitro activity against CR-GNB and have attracted much interest as novel, less toxic, and possibly more efficacious options for the treatment of CR-GNB VAP compared with previous standard of care. Besides randomized controlled trials, a good solution to enrich our knowledge on how to use these novel agents at best in the near future, while at the same time remaining adherent to current evidence-based guidelines, is to improve our collaboration to conduct larger multinational observational studies to collect sufficiently large populations treated in real life with those novel agents for which guidelines currently do not provide a recommendation (in favor or against) for certain causative organisms.

Using a Validated Population Pharmacokinetic Model for Dosing Recommendations of Continuous Infusion Piperacillin for Critically Ill Adult Patients

BACKGROUND AND OBJECTIVE: Piperacillin is a broad-spectrum β-lactam antibiotic commonly prescribed in intensive care units. Many piperacillin population pharmacokinetic models have been published, but few underwent an external evaluation. External evaluation is an important process to determine a model's capability of being generalized to other hospitals. We aimed to assess the predictive performance of these models with an external validation dataset.

METHODS

Six models were evaluated with a dataset consisting of 30 critically ill patients (35 samples) receiving piperacillin by continuous infusion. Models were subject to prediction-based (bias and imprecision) and simulation-based evaluations. When a model had an acceptable evaluation, it was used for dosing simulations to evaluate the probability of target attainment.

RESULTS

Bias and imprecision ranged from - 35.7 to 295% and from 22.7 to 295%, respectively. The models of Klastrup et al. and of Udy et al. were acceptable according to our criteria and were used for dosing simulations. Simulations showed that a loading dose of 4 g followed by a maintenance dose of 16 g/24 h of piperacillin infused continuously was necessary to remain above a pharmacokinetic-pharmacodynamic target set as a minimal inhibitory concentration of 16 mg/L in 90% of patients, for a median patient with a creatinine clearance of 76 mL/min.

CONCLUSIONS

Despite the considerable variation in the predictive performance of the models with the external validation dataset, this study was able to validate two of these models and led to the elaboration of a dosing nomogram for piperacillin by continuous infusion that can be used by clinicians in intensive care units.

Effect of Different Piperacillin-Tazobactam Dosage Regimens on Synergy of the Combination with Tobramycin against Pseudomonas aeruginosa for the Pharmacokinetics of Critically Ill Patients in a Dynamic Infection Model

We evaluated piperacillin-tazobactam and tobramycin regimens against Pseudomonas aeruginosa isolates from critically ill patients. Static-concentration time-kill studies (SCTK) assessed piperacillin-tazobactam and tobramycin monotherapies and combinations against four isolates over 72 h. A 120 h-dynamic in vitro infection model (IVM) investigated isolates Pa1281 (MIC_piperacillin 4 mg/L, MIC_tobramycin 0.5 mg/L) and CR380 (MIC_piperacillin 32 mg/L, MIC_tobramycin 1 mg/L), simulating the pharmacokinetics of: (A) tobramycin 7 mg/kg q24 h (0.5 h-infusions, t_1/2 = 3.1 h); (B) piperacillin 4 g q4 h (0.5 h-infusions, t_1/2 = 1.5 h); (C) piperacillin 24 g/day, continuous infusion; A + B; A + C. Total and less-susceptible bacteria were determined. SCTK demonstrated synergy of the combination for all isolates. In the IVM, regimens A and B provided initial killing, followed by extensive regrowth by 72 h for both isolates. C provided >4 log₁₀ CFU/mL killing, followed by regrowth close to initial inoculum by 96 h for Pa1281, and suppressed growth to <4 log₁₀ CFU/mL for CR380. A and A + B initially suppressed counts of both isolates to <1 log₁₀ CFU/mL, before regrowth to control or starting inoculum and resistance emergence by 72 h. Overall, the combination including intermittent piperacillin-tazobactam did not provide a benefit over tobramycin monotherapy. A + C, the combination regimen with continuous infusion of piperacillin-tazobactam, provided synergistic killing (counts <1 log₁₀ CFU/mL) of Pa1281 and CR380, and suppressed regrowth to <2 and <4 log₁₀ CFU/mL, respectively, and resistance emergence over 120 h. The shape of the concentration–time curve was important for synergy of the combination.

Association between Serum Prolactin Levels and Neurodegenerative Diseases: Systematic Review and Meta-Analysis

INTRODUCTION

Prolactin (PRL) exerts inflammatory and anti-inflammatory properties and is also thought to play an important role in the pathogenesis of neurodegenerative diseases (NDs). However, serum PRL levels in patients with NDs were inconsistent in the research literature.

OBJECTIVE

We aimed to assess the serum PRL levels in patients with NDs.

METHODS

Electronic databases, including MEDLINE, Embase, Cochrane Library database, clinicaltrials.gov, Web of Science, and Google Scholar, and reference lists of articles were searched up to December 31, 2020. Pooled standard mean difference (SMD) with 95% confidence interval (CI) was calculated by fixed-effect or random-effect model analysis.

RESULTS

A total of 36 comparisons out of 29 studies (3 RCTs and 26 case controls) focusing on NDs (including Parkinson's disease, Alzheimer's disease, Huntington's disease [HD], multiple sclerosis [MS], and epilepsy) were reported. The meta-analysis showed that there was no statistically significant difference in serum PRL levels between patients with NDs and healthy controls (SMD = 0.40, 95% CI: -0.16 to 0.96, p = 0.16). Subgroup analysis showed that serum PRL levels in patients with HD and MS were higher than those of healthy controls. Furthermore, patients with NDs aged <45 years had higher serum PRL levels (SMD = 0.97, 95% CI: 0.16-1.78, p = 0.018) than healthy controls. High serum PRL levels were found in subgroups such as the microenzymatic method, Asia, and the Americas.

CONCLUSIONS

Our meta-analysis showed serum PRL levels in patients with HD and MS were significantly higher than those in healthy controls. Serum PRL levels were associated with age, region, and detection method. Other larger sample studies using more uniform detection methods are necessary to confirm our results.

Prolonged infusion of beta-lactam antibiotics for Gram-negative infections: rationale and evidence base

PURPOSE OF REVIEW

The aim of this review is to discuss the rationale of and current evidence for prolonged beta-lactam infusion in the management of Gram-negative infections.

RECENT FINDINGS

Pharmacokinetic/pharmacodynamic (PK/PD) data from various in-vitro and in-vivo experimental studies conclusively support prolonged infusion over intermittent infusion in terms of achieving effective beta-lactam exposure for maximal bacterial killing. Superior PK/PD target attainment has been demonstrated with prolonged beta-lactam infusion in patient populations that are more likely to have less susceptible Gram-negative infections. These populations include critically ill patients, cystic fibrosis patients and patients with malignant diseases. The clinical impact of prolonged beta-lactam infusion is likely to be the greatest in these patient groups: critically ill patients with a high level of illness severity who are not receiving renal replacement therapy; patients with nonfermenting Gram-negative bacilli infection and patients with respiratory infection. Critically ill patients with augmented renal clearance may not achieve effective beta-lactam exposure even with the use of prolonged infusion. Maximizing the effectiveness of prolonged beta-lactam infusion via therapeutic drug monitoring is becoming a more common strategy in the management of critically ill patients with Gram-negative infection.

SUMMARY

Prolonged beta-lactam infusion may not benefit all patients but only for those who are critically ill and/or immunocompromised, who are also more likely to have less susceptible Gram-negative infections.

Piperacillin-Tazobactam in Intensive Care Units: A Review of Population Pharmacokinetic Analyses

Piperacillin-tazobactam is a potent β-lactam/β-lactamase inhibitor antibiotic commonly prescribed in the intensive care unit setting. Admitted patients often show large variability in treatment response due to multiple pathophysiological changes present in this population that alter the drug's pharmacokinetics. This review summarizes the population pharmacokinetic models developed for piperacillin-tazobactam and provides comprehensive data on current dosing strategies while identifying significant covariates in critically ill patients. A literature search on the PubMed database was conducted, from its inception to July 2020. Relevant articles were retained if they met the defined inclusion/exclusion criteria. A total of ten studies, published between 2009 and 2020, were eligible. One- and two-compartment models were used in two and eight studies, respectively. The lowest estimated piperacillin clearance value was 3.12 L/h, and the highest value was 19.9 L/h. The estimations for volume of distribution varied between 11.2 and 41.2 L. Tazobactam clearance values ranged between 5.1 and 6.78 L/h, and tazobactam volume of distribution values ranged between 17.5 and 76.1 L. The most frequent covariates were creatinine clearance and body weight, each present in four studies. Almost all studies used an exponential approach for the interindividual variability. The highest variability was observed in piperacillin central volume of distribution, at a value of 75.0%. Simulations showed that continuous or extended infusion methods performed better than intermittent administration to achieve appropriate pharmacodynamic targets. This review synthesizes important pharmacokinetic elements for piperacillin-tazobactam in an intensive care unit setting. This will help clinicians better understand changes in the drug's pharmacokinetic parameters in this specific population.

Issues in antibiotic therapy for hospital-acquired and ventilator-associated pneumonia: emerging concepts to improve outcomes

Introduction:Ventilator-associated pneumonia (VAP) and hospital-acquired pneumonia (HAP) result in significant morbidity and mortality. The emergence of multi-drug resistant organisms has complicated the matter, as many of these pathogens now represent key causes of VAP and HAP. While anumber of new medications have been approved, acomprehensive appreciation of pharmacokinetic and pharmacodynamic principles, which, are often neglected, is key to effective treatment.Areas covered: The authors discuss the central pharmacokinetic and pharmacodynamic principles underlying antibiotic utilization, especially as they pertain to the treatment of VAP and HAP. They further address the concept of and implications of augmented renal clearance for the patient with nosocomial pneumonia. Finally, the authors review the evolving data on colistin and inhaled antibiotics in the management of pneumonia.Expert opinion: An enhanced understanding of the pharmacokinetic and pharmacodynamic principles along with insight into the concept of augmented renal clearance can help guide drug development and improve the way we currently dose and deliver most antibiotics. There is now mounting data on the limited efficacy and substantial nephrotoxicity of colistin, which makes it difficult to justify its continued use. While the concept of inhaled antibiotics is enticing, we lack conclusive data proving the efficacy of this paradigm.