Clinical outcomes of extended versus intermittent administration of piperacillin/tazobactam for the treatment of hospital-acquired pneumonia: a randomized controlled trial

Continuous infusion of beta-lactam antibiotics in pediatric intensive care unit: A monocenter before/after implementation study

CONTEXT

Beta-lactam continuous infusion (CI) is currently recommended in adult intensive care units to achieve target concentrations. In pediatric intensive care (PICU), few studies suggest the value of Beta-lactam CI to achieve target concentration. Our objective was to analyze the impact of Beta-lactam CI protocolization on the achievement of target concentration in PICU patients.

MATERIAL AND METHODS

We conducted a single-center retrospective study in patients with beta-lactam treatment for more than 2 days and at least one sample for therapeutic drug monitoring (TDM). From January 2018 to February 2022 (period 1, P1), BL were administered as an intermittent infusion with TDM upon request. From February to September 2022 (period 2, P2), Beta-lactam CI with TDM at day one was protocolized. The primary endpoint concerned achieving fT>4× Minimum Inhibitory Concentration = 100%.

RESULTS

In P1, 214 assays involved 103 patients; in P2, 199 assays involved 72 patients. Target concentration achievement was more frequent in P2 (P2 = 73.7% vs. P1 = 29.1%; p < 0.001). At day 5/6 after Beta-lactam initiation, c-reactive protein concentrations were P1 = 84.9 ± 79.2 mg/L; P2 = 53.7±49.8 mg/L (p < 0.05). In the multivariable logistic regression model: P2, BSA, and albumin were positively associated with target achievement; urea, and male sex were negatively associated with target achievement. The daily average cost of beta-lactam vial consumption per child was: P1 = 5.04 ± 2.6 € vs. P2 = 3.21 ± 2.7 € (p-value < 0.001). The daily average reconstitution time of Beta-lactam syringes per child was: P1 = 23.5 ± 8.7 min, P2 = 13.9 ± 9.2 min (p-value < 0.001).

CONCLUSION

Protocolization of Beta-lactam continuous infusion was associated with more frequent target concentration achievements in PICU. This implementation could be cost-effective and nurse time-saving.

Chemical stability and physical compatibility of meropenem in admixtures for continuous and extended intravenous infusions

INTRODUCTION

Prolonged intravenous infusion of beta-lactams increase the clinical cure rate compared to conventional administration in critical or septic patients. This study aimed to determine chemical stability and physical compatibility of meropenem at conditions used in clinical practice to evaluate the stability of the preparation during its administration and the possibility of anticipated preparation.

METHODS

Admixtures in study were: (i) meropenem 6g in 0.9% sodium chloride (NS) in infusor of 2mL/h 50mL or 10mL/h 240mL; (ii) meropenem 1 or 2g in NS in infusion bag of 250mL. Temperatures of study were: (i) infusor: 4.5°C, 32°C or 12h at 4.5°C followed by 32°C; (ii) Infusion bag: 4.5°C, 24.5°C or 6h at 4.5°C followed by 24.5°C. Time of study was 5-6 days in infusor and 1 day in infusion bag. Chemical stability was evaluated by high performance liquid chromatography and physical compatibility by measuring pH and visual inspection.

RESULTS

Chemical stability and physical compatibility of meropenem in admixtures in infusors were reduced at high meropenem concentration and high temperature. Admixtures in infusion bag show chemical stability and physical compatibility for at least 1 day.

CONCLUSION

Administration of meropenem 6g in infusion of 24h in 240mL of 0.9% NaCl in infusor of 10mL/h could be possible if the admixture is infused at 4.5°C. Extended infusion of meropenem 1 or 2g in 0.9% NaCl in infusion bag (250mL) in 3-4h is also feasible. Anticipated preparation of the admixtures in infusion bag is possible with a stability of 24h.

International consensus recommendations for the use of prolonged-infusion beta-lactam antibiotics: Endorsed by the American College of Clinical Pharmacy, British Society for Antimicrobial Chemotherapy, Cystic Fibrosis Foundation, European Society of Clinical Microbiology and Infectious Diseases, Infectious Diseases Society of America, Society of Critical Care Medicine, and Society of Infectious Diseases Pharmacists

Intravenous β-lactam antibiotics remain a cornerstone in the management of bacterial infections due to their broad spectrum of activity and excellent tolerability. β-lactams are well established to display time-dependent bactericidal activity, where reductions in bacterial burden are directly associated with the time that free drug concentrations remain above the minimum inhibitory concentration (MIC) of the pathogen during the dosing interval. In an effort to take advantage of these bactericidal characteristics, prolonged (extended and continuous) infusions (PIs) can be applied during the administration of intravenous β-lactams to increase time above the MIC. PI dosing regimens have been implemented worldwide, but implementation is inconsistent. We report consensus therapeutic recommendations for the use of PI β-lactams developed by an expert international panel with representation from clinical pharmacy and medicine. This consensus guideline provides recommendations regarding pharmacokinetic and pharmacodynamic targets, therapeutic drug-monitoring considerations, and the use of PI β-lactam therapy in the following patient populations: severely ill and nonseverely ill adult patients, pediatric patients, and obese patients. These recommendations provide the first consensus guidance for the use of β-lactam therapy administered as PIs and have been reviewed and endorsed by the American College of Clinical Pharmacy (ACCP), the British Society for Antimicrobial Chemotherapy (BSAC), the Cystic Fibrosis Foundation (CFF), the European Society of Clinical Microbiology and Infectious Diseases (ESCMID), the Infectious Diseases Society of America (IDSA), the Society of Critical Care Medicine (SCCM), and the Society of Infectious Diseases Pharmacists (SIDP).

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.

Continuous Piperacillin-Tazobactam Infusion Improves Clinical Outcomes in Critically Ill Patients with Sepsis: A Retrospective, Single-Centre Study

Continuous infusion of beta-lactam antibiotics has emerged as an alternative for the treatment of sepsis because of the favourable pharmacokinetics of continuous infusion. This study aimed to evaluate the survival benefits of continuous vs. intermittent infusion of piperacillin-tazobactam in critically ill patients with sepsis. We retrospectively conducted a single-centre study of continuous infusion vs. intermittent infusion of piperacillin-tazobactam for adult patients who met the Sepsis-3 criteria and were treated at a medical ICU within 48 h after hospitalisation between 1 May 2018 and 30 April 2020. The primary outcome was mortality at 28 days. A total of 157 patients (47 in the continuous group and 110 in the intermittent group) met the inclusion criteria for evaluation. The 28-day mortality rates were 12.8% in the continuous group and 27.3% in the intermittent group (p = 0.07). However, after adjustment for potential covariables, patients in the continuous group (12.8%) showed significantly lower mortality at 28 days than those in the intermittent group (27.3%; adjusted hazard ratio (HR), 0.31; 95% confidence interval (CI), 0.13-0.79; p = 0.013). In sepsis patients, continuous infusion of piperacillin-tazobactam may confer a benefit regarding the avoidance of mortality at 28 days compared with intermittent infusion.

Why We May Need Higher Doses of Beta-Lactam Antibiotics: Introducing the 'Maximum Tolerable Dose'

The surge in antimicrobial resistance and the limited availability of new antimicrobial drugs has fueled the interest in optimizing antibiotic dosing. An ideal dosing regimen leads to maximal bacterial cell kill, whilst minimizing the risk of toxicity or antimicrobial resistance. For beta-lactam antibiotics specifically, PK/PD-based considerations have led to the widespread adoption of prolonged infusion. The rationale behind prolonged infusion is increasing the percentage of time the beta-lactam antibiotic concentration remains above the minimal inhibitory concentration (%fT>MIC). The ultimate goal of prolonged infusion of beta-lactam antibiotics is to improve the outcome of infectious diseases. However, merely increasing target attainment (or the %fT>MIC) is unlikely to lead to improved clinical outcome for several reasons. First, the PK/PD index and target are dynamic entities. Changing the PK (as is the case if prolonged instead of intermittent infusion is used) will result in different PK/PD targets and even PK/PD indices necessary to obtain the same level of bacterial cell kill. Second, the minimal inhibitory concentration is not a good denominator to describe either the emergence of resistance or toxicity. Therefore, we believe a different approach to antibiotic dosing is necessary. In this perspective, we introduce the concept of the maximum tolerable dose (MTD). This MTD is the highest dose of an antimicrobial drug deemed safe for the patient. The goal of the MTD is to maximize bacterial cell kill and minimize the risk of antimicrobial resistance and toxicity. Unfortunately, data about what beta-lactam antibiotic levels are associated with toxicity and how beta-lactam antibiotic toxicity should be measured are limited. This perspective is, therefore, a plea to invest in research aimed at deciphering the dose−response relationship between beta-lactam antibiotic drug concentrations and toxicity. In this regard, we provide a theoretical approach of how increasing uremic toxin concentrations could be used as a quantifiable marker of beta-lactam antibiotic toxicity.

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.

A Review of Extended and Continuous Infusion Beta-Lactams in Pediatric Patients

Intravenous beta-lactam antibiotics are the most prescribed antibiotic class in US hospitalized patients of all ages; therefore, optimizing their dosing is crucial. Bactericidal killing is best predicted by the time in which beta-lactam drug concentrations are maintained above the organism's minimum inhibitory concentration (MIC), rather than achievement of a high peak concentration. As such, administration of beta-lactam antibiotics via extended or continuous infusions over a minimum of 3 hours, rather than standard infusions over approximately 30 minutes, has been associated with improved achievement of pharmacodynamic targets and improved clinical outcomes in adult medical literature. This review summarizes the pediatric medical literature. Applicable studies include pharmacodynamic models, case series, retrospective analyses, and prospective studies on the use of extended infusion and continuous infusion penicillins, cephalosporins, carbapenems, and monobactams in neonates, infants, children, and adolescents. Specialized patient populations with unique pharmacokinetics and high-risk infections (neonates, critically ill, febrile neutropenia, cystic fibrosis) are also reviewed. While more studies are needed to confirm prospective clinical outcomes, the current body of evidence suggests extended and continuous infusions of beta-lactam antibiotics are well tolerated in children and improve achievement of pharmacokineticpharmacodynamic targets with similar or superior clinical outcomes, particularly in infections associated with high MICs.

Cefoperazone sodium/sulbactam sodium vs piperacillin sodium/tazobactam sodium for treatment of respiratory tract infection in elderly patients

BACKGROUND

Respiratory tract infections in the elderly are difficult to cure and can easily recur, thereby posing a great threat to patient prognosis and quality of life.

AIM

To investigate the therapeutic effects of different antibiotics in elderly patients with respiratory tract infection.

METHODS

Seventy-four elderly patients with respiratory tract infection were randomly allocated to a study (n = 37; treated with cefoperazone sodium/sulbactam sodium) or control (n = 37; treated with piperacillin sodium/tazobactam sodium on the basis of routine symptomatic support) group. Both groups were treated for 7 d. Time to symptom relief (leukocyte recovery; body temperature recovery; cough and sputum disappearance; and rale disappearance time), treatment effect, and laboratory indexes [procalcitonin (PCT), C-reactive protein (CRP), white blood cell count (WBC), and neutrophil percentage (NE)] before and 7 d after treatment and the incidence of adverse reactions were assessed.

RESULTS

In the study group, the time to WBC normalization (6.79 ± 2.09 d), time to body temperature normalization (4.15 ± 1.08 d), time to disappearance of cough and sputum (6.19 ± 1.56 d), and time to disappearance of rales (6.68 ± 1.43 d) were shorter than those of the control group (8.89 ± 2.32 d, 5.81 ± 1.33 d, 8.77 ± 2.11 d, and 8.69 ± 2.12 d, respectively; P = 0.000). Total effective rate was higher in the study group (94.59% vs 75.68%, P = 0.022). Serum PCT (12.89 ± 3.96 μg/L), CRP (19.62 ± 6.44 mg/L), WBC (20.61 ± 6.38 × 10⁹/L), and NE (86.14 ± 7.21%) levels of the study group before treatment were similar to those of the control group (14.05 ± 4.11 μg/L, 18.79 ± 5.96 mg/L, 21.21 ± 5.59 × 10⁹/L, and 84.39 ± 6.95%, respectively) with no significant differences (P = 0.220, 0.567, 0.668, and 0.291, respectively). After 7 d of treatment, serum PCT, CRP, WBC, and NE levels in the two groups were lower than those before treatment. Serum PCT (2.01 ± 0.56 μg/L), CRP (3.11 ± 1.02 mg/L), WBC (5.10 ± 1.83 × 10⁹/L), and NE (56.35 ± 7.17%) levels were lower in the study group than in the control group (3.29 ± 0.64 μg/L, 5.67 ± 1.23 mg/L, 8.13 ± 3.01 × 10⁹/L, and 64.22 ± 8.08%, respectively; P = 0.000). There was no significant difference in the incidence of adverse reactions between the groups (7.50% vs 12.50%, P = 0.708).

CONCLUSION

Piperacillin sodium/tazobactam sodium is superior to cefoperazone sodium/ sulbactam sodium in the treatment of elderly patients with respiratory tract infection with a similar safety profile.

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.

Personalized ß-lactam dosing in patients with coronavirus disease 2019 (COVID-19) and pneumonia: A retrospective analysis on pharmacokinetics and pharmacokinetic target attainment

ABSTRACT

Pathophysiological changes are important risk factors for critically ill patients with pneumonia manifesting sub-therapeutic antibiotic exposures during empirical treatment. The effect of coronavirus disease 2019 (COVID-19) on antibiotic dosing requirements is uncertain. We aimed to determine the effect of COVID-19 on ß-lactam pharmacokinetics (PK) and PK target attainment in critically ill patients with a personalized dosing strategy.Retrospective, single-center analysis of COVID-19 ± critically ill patients with pneumonia (community-acquired pneumonia or hospital-acquired pneumonia) who received continuous infusion of a ß-lactam antibiotic with dosing personalized through dosing software and therapeutic drug monitoring. A therapeutic exposure was defined as serum concentration between (css) 4 to 8 times the EUCAST non-species related breakpoint).Data from 58 patients with pneumonia was analyzed. Nineteen patients were tested COVID-19-positive before the start of the antibiotic therapy for community-acquired pneumonia or hospital-acquired pneumonia. Therapeutic exposure was achieved in 71% of COVID-19 patients (68% considering all patients). All patients demonstrated css above the non-species-related breakpoint. Twenty percent exceeded css above the target range (24% of all patients). The median ß-lactam clearance was 49% compared to ß-lactam clearance in a standard patient without a significant difference regarding antibiotic, time of sampling or present COVID-19 infection. Median daily doses were 50% lower compared to standard bolus dosing.COVID-19 did not significantly affect ß-lactam pharmacokinetics in critically ill patients. Personalized ß-lactam dosing strategies were safe in critically ill patients and lead to high PK target attainment with less resources.

Comparison of piperacillin plasma concentrations in a prospective randomised trial of extended infusion versus intermittent bolus of piperacillin/tazobactam in paediatric patients

OBJECTIVES

To be effective, piperacillin/tazobactam (PTZ) unbound plasma levels need to be above the minimum inhibitory concentration (MIC) at least 50% of the time between dosing intervals (50% fT_>MIC). This study aimed to compare the plasma piperacillin concentrations at the mid-dosing intervals (C_mid, 50% fT) and the proportion of patients achieving 50% fT_>MIC between extended infusion (EI) and intermittent bolus (IB) methods in children.

METHODS

A prospective, randomised trial of EI versus IB of PTZ was conducted in children aged 1 month to 18 years. The PTZ dose was 100 mg/kg intravenously every 8 h. Patients were randomly assigned to receive EI (4-h infusion) or IB (30-min infusion). The primary outcome that was measured was plasma piperacillin C_mid.

RESULTS

Ninety patients with a median age (IQR) of 48 months (16-127) were enrolled. The most common indication for PTZ use was pneumonia (32.2%). Geometric mean (95% CI) plasma piperacillin C_mid of EI versus IB was 51.9 mg/L (40.6-66.6) versus 6.0 mg/L (4.2-8.6) (P < 0.01). The EI group had a trend of higher proportion of patients who achieved 50% fT_>4xMIC (72.7% versus 30.0%; P = 0.06).

CONCLUSIONS

PTZ administration with EI resulted in a higher C_mid compared with IB. In settings with increased piperacillin MICs, this approach should be implemented, particularly during the empirical treatment period.

Loading dose and efficacy of continuous or extended infusion of beta-lactams compared with intermittent administration in patients with critical illnesses: A subgroup meta-analysis and meta-regression analysis

WHAT IS KNOWN AND OBJECTIVE

The role of continuous/extended beta-lactam infusions (CEIs) in improving clinical outcomes among critically ill patients remains controversial. Therefore, we aimed to compare the clinical efficacy of CEI versus intermittent administration (IA) of beta-lactams by performing a systematic review and meta-analysis.

METHODS

PubMed, the Cochrane Library and Embase were searched from inception until December 2018 for studies comparing clinical outcomes of CEI versus IA in critically ill patients. The meta-analysis included 18 randomized controlled trials (RCTs) and 13 non-RCTs.

RESULTS AND DISCUSSION

For CEI versus IA, the summary relative risk (RR) for overall mortality and clinical cure was 0.82 (95% confidence interval [CI]: 0.72-0.94) and 1.31 (95% CI: 1.15-1.49), respectively. Subgroup and meta-regression analyses of the loading dose revealed a significantly increased clinical cure rate in the loading-dose group (RR: 1.44, 95% CI: 1.22-1.69), which remained significant after adjustments for beta-lactam type, and association between clinical cure and loading dose for clinical cure (RR: 1.47, 95% CI: 1.20-1.80; p = .001). Subgroup analysis of administration type indicated that both groups had low mortality and high clinical cure rates; however, the heterogeneity analysis did not support an association across continuous infusion and extended infusion groups. Subgroup analysis of the Acute Physiology and Chronic Health Evaluation (APACHE) score was conducted; according to APACHE scores ≥ 16, overall mortality and clinical cure significantly differed between CEI and IA.

WHAT IS NEW AND CONCLUSION

CEIs with loading-dose treatment may significantly improve the clinical outcomes in critically ill sepsis or septic shock patients.

<p>Optimal Empiric Treatment for <em>Klebsiella pneumoniae</em> Infections in Short-Stay ICU Patients During Continuous Renal Replacement Therapy: Results from a Population Pharmacokinetic/Pharmacodynamic Analysis</p>

Objective

There is a paucity of published data to evaluate the efficacy and safety of imipenem (IPM) and piperacillin-tazobactam (PT) dosing regimens in the treatment of septic patients acquiring continuous renal replacement therapy (CRRT).

Methods and Materials

Critically-ill patients were grouped into short-stay and long-stay intensive care unit (ICU) patients. Pathogens were isolated from bloodstream infections in these patients. Minimum inhibitory concentration (MIC) value was determined by agar dilution method. Population PK models were introduced in this study, and differences in the likelihood of achieving efficacious and toxic exposures of IPM and PT for critically-ill patients were assessed.

Results

A total of 86 K. pneumoniae bloodstream infection associated isolates were collected, and the MIC₅₀ and MIC₉₀ for short-stay ICU patients were 0.5/4 mg/L and 32/128 mg/L, respectively. IMP 0.5g q8h reached 90% probability of target attainment (PTA) against isolates with MICs ≤2 mg/L and was recommended to empirically treat short-stay ICU patients during CRRT based on the target of 40% ƒT>MIC. However, based on a more aggressive target of 100% ƒT>MIC, all the simulated IMP regimens except for IMP 1g q6h failed to achieve >80% cumulative fraction of response (CFR) in such patients. Unfortunately, the risk of drug-related toxicity for IMP 1g q6h was relatively high (50–85%). For PT, even the regimen of 4/0.5g q6h failed to provide sufficient antimicrobial exposure in short-stay ICU patients acquiring CRRT.

Conclusion

No dose adjustment was required for the conventional IMP and PT regimens in the critically-ill population acquiring CRRT. Empirical treatment of IMP 0.5g q8h/q6h, not for PT, may provide sufficient antimicrobial exposure for short-stay ICU patients during CRRT. PT should be used in the knowledge of MIC results.

Benefits of prolonged infusion of beta-lactam antibiotics in patients with sepsis: personal perspectives

INTRODUCTION

In the current era of relatively scarce antibiotic production and significant levels of antimicrobial resistance, optimization of pharmacokinetics and pharmacodynamics of antibiotic therapy is mandatory. Prolonged infusion of beta-lactam antibiotics in comparison to the intermittent infusion has the theoretical advantage of better patient outcomes. Apparently, conflicting data in the literature possibly underestimate the benefits of prolonged infusion of antibiotic treatment.

AREAS COVERED

We provide our perspective on the subject based on our experience and by critically evaluating literature data.

EXPERT OPINION COMMENTARY

In our opinion, the available data are suggestive of the beneficial role of prolonged infusion of beta-lactams in regard to piperacillin/tazobactam and carbapenems after administering a loading dose. While more data from randomized controlled trials are necessary to solidify or negate the evident benefits of prolonged infusion of the aforementioned antibiotics, clinicians should strongly consider this mode of administration of relevant antibiotics, especially in patients with severe infections.

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

Background

Recently, continuous administration of piperacillin-tazobactam has been proposed as a valuable alternative to traditional intermittent administration especially in critically ill patients. However, antibiotic dosing remains a challenge for clinicians as antibiotic dosing regimens are usually determined in non-critically ill hospitalized adult patients. The aim was to conduct a systematic review to identify and highlight studies comparing clinical outcomes of piperacillin tazobactam dosing regimens, continuous/prolonged infusion vs intermittent infusion in critically ill patients. Meta-analyses were performed to assess the overall effect of dosing regimen on clinical efficacy.

Methods

Studies were identified systematically through searches of PubMed and Science Direct, in compliance with PRISMA guidelines. Following the systematic literature review, meta-analyses were performed using Review Manager.

Results

Twenty-three studies were included in the analysis involving 3828 critically ill adult participants in total (continuous/prolonged infusion = 2197 and intermittent infusion = 1631) from geographically diverse regions. Continuous/prolonged resulted in significantly: higher clinical cure rates (Odds Ratio 1.56, 95% Confidence Interval 1.28–1.90, P = 0 .0001), lower mortality rates (Odds Ratio 0.68, 95% Confidence Interval 0.55–0.84, P = 0 .0003), higher microbiological success rates (Odds Ratio 1.52, 95% Confidence Interval 1.10–2.11, P = 0.01) and decreasing the length of hospital stay (Mean Difference − 1.27, 95% Confidence Interval − 2.45—0.08, P = 0.04) in critically ill patients.

Conclusion

Results from this study show that there is a significant level of evidence that clinical outcome in critically ill patients is improved in patients receiving piperacillin-tazobactam via continuous/prolonged infusion. However, more rigorous scientific studies in critically ill patients are warranted to reach a sufficient level of evidence and promote further implementation of C/PI as a dosing strategy.

Implementation of an Extended-Infusion Piperacillin-Tazobactam Dosing Protocol: Unexpected Findings when Monitoring Safety and Compliance with Smart Pump Technology

Compliance with recommended infusion rates was evaluated before, during, and after the implementation of extended-infusion (EI) piperacillin-tazobactam at an academic medical center. Software-controlled infusion-pump alert data were studied for piperacillin-tazobactam administrations before and after implementation of a four-hour EI protocol. Compliance was analyzed 16 weeks before (pre-EI), two weeks after (peri-EI), and an additional 16 weeks after (post-EI) protocol implementation. We defined potential harm as a programmed infusion rate exceeding the recommended rate, possible harm as a programmed infusion aborted by the user, and compliance as reversion to recommended rates. Potential and possible harm were standardized to 1000 patient days. Overall, 3110 alerts were identified during the period. Potential harm per 1000 patient days for pre-, peri-, and post-EI were 0, 6.12, and 1.05 (p < 0.001). Possible harm per 1000 patient days for the pre-, peri-, and post-EI were 0.33, 21.9, and 5.02 (p < 0.001). Compliance after an initial potential harm alert occurred more often post-EI (0.4 per 1000 patient days vs. 0 per 1000 patient days for pre- and peri-EI; p < 0.001), while alerts remaining in non-compliance were more prevalent if they initially occurred during the peri- and post-EI vs. pre-EI (6.1 and 0.6 per 1000 patient days vs. 0 per 1000 patient days; p < 0.001) period. Piperacillin-tazobactam infusions were administered faster than recommended during implementation (i.e., peri-EI) despite standardized orders.

The Pharmacodynamics of Prolonged Infusion β-Lactams for the Treatment of Pseudomonas aeruginosa Infections: A Systematic Review

PURPOSE

Pseudomonas aeruginosa is a commonly isolated nosocomial pathogen for which treatment options are often limited for multidrug-resistant isolates. In addition to newer available antimicrobial agents active against P. aeruginosa, strategies such as extended (eg, prolonged or continuous) infusion have been suggested to optimize the pharmacokinetic and pharmacodynamic profiles of β-lactams. Literature regarding clinical outcomes for extended infusion β-lactams has been controversial; however, this use seems most beneficial in patients with severe illness. Prolonged infusion of β-lactams (eg, 3- to 4-hour infusion) can enhance the pharmacodynamic target attainment via increasing the amount of time throughout the dosing interval to which the free drug concentration remains above the MIC (minimum inhibitory concentration) of the organism (fT > MIC). This systematic review summarizes current literature related to the probability of target attainment (PTA) of various antipseudomonal β-lactam regimens administered as prolonged infusions in an effort to provide guidance in selecting optimal dosing regimens and infusion times for the treatment of P. aeruginosa infections.

METHODS

A literature search for all pertinent studies was performed by using the PubMed database (with no year limit) through March 31, 2019.

FINDINGS

Thirty-nine studies were included. Although many standard antipseudomonal β-lactam intermittent infusion regimens can provide adequate PTA against most susceptible isolates, prolonged infusion may enhance percent fT > MIC for organisms with higher MICs (eg, nonsusceptible) or patients with altered pharmacokinetic profiles (eg, obese, critically ill, those with febrile neutropenia).

IMPLICATIONS

Prolonged infusion β-lactam regimens can enhance PTA against nonsusceptible P. aeruginosa isolates and may provide a potential therapeutic option for multidrug-resistant infections. Before implementing prolonged infusion antipseudomonal β-lactams, institutions should consider the half-life of the antibiotic, local incidence of P. aeruginosa infections, antibiotic MIC distributions or MICs isolated from individual patients, individual patient characteristics that may alter pharmacokinetic variables, and PTA (eg, critically ill), as well as implementation challenges.

Population Pharmacokinetics and Safety of Piperacillin-Tazobactam Extended Infusions in Infants and Children

Piperacillin-tazobactam (TZP) is frequently used to treat severe hospital-acquired infections in children. We performed a single-center, pharmacokinetic (PK) trial of TZP in children ranging in age from 2 months to 6 years from various clinical subpopulations. Children who were on TZP per the standard of care were prospectively included and assigned to receive a dose of 80 mg/kg of body weight every 6 h infused over 2 h (ages 2 to 5 months) or a dose of 90 mg/kg every 8 h infused over 4 h (ages 6 months to 6 years). Separate population PK models were developed for piperacillin and tazobactam using nonlinear mixed-effects modeling. Optimal dosing was judged based on the ability to maintain free piperacillin concentrations above the piperacillin MIC for enterobacteria and Pseudomonas aeruginosa for ≥50% of the dosing interval. Any untoward event occurring during treatment was collected as an adverse event. A total of 79 children contributed 174 PK samples. The median (range) age and weight were 1.7 years (2 months to 6 years) and 11.4 kg (3.8 to 27.6 kg), respectively. A 2-compartment model with first-order elimination best described the piperacillin and tazobactam data. Both final population PK models included weight and concomitant furosemide administration on clearance and weight on the volume of distribution of the central compartment. The optimal dosing regimens in children with normal renal function, based on the piperacillin component, were 75 mg/kg/dose every 4 h infused over 0.5 h in infants ages 2 to ≤6 months and 130 mg/kg/dose every 8 h infused over 4 h in children ages >6 months to 6 years against bacteria with MICs up to 16 mg/liter. A total of 44 children (49%) had ≥1 adverse event, with 3 of these (site infiltrations) considered definitely associated with the extended infusions.

Prolonged infusion with β-lactam antibiotics for treatment of infection caused by non-susceptible bacteria: a study protocol for a systemic review and meta-analysis

INTRODUCTION

Prolonged infusion with β-lactam antibiotics should theoretically produce a better clinical efficacy than intermittent infusion in severe infection and infection caused by non-susceptible micro-organisms. The efficacy of prolonged infusion in severe infection has been well illustrated recently, but is still confusing in non-susceptible microbial infection. The objective of this meta-analysis is to determine the clinical effects of prolonged infusion with β-lactams for patients infected by microbes non-susceptible to the given drug.

METHODS AND ANALYSIS

Literature searches will be performed with Medline, the Cochrane database, EMBASE database, Cumulative Index to Nursing and Allied Health Literature database, the Chinese National Knowledge Infrastructure and Wanfang database. Two reviewers will screen and select studies according to a priori defined eligibility criteria, and then the data from the included studies will be extracted. The quality will be evaluated based on a modified Jadad score and the Newcastle-Ottawa system for randomised controlled trials and observational studies, respectively. Data synthesis will be performed with Review Manager 5.3 software. Sensitivity analysis and publication bias will also be investigated.

ETHICS AND DISSEMINATION

No ethics approval is required. The full article will be published in a peer-reviewed journal and presented at international conferences.

PROSPERO REGISTRATION NUMBER

CRD42018105111.

Scaling beta-lactam antimicrobial pharmacokinetics from early life to old age

AIMS

Beta-lactam dose optimization in critical care is a current priority. We aimed to review the pharmacokinetics (PK) of three commonly used beta-lactams (amoxicillin ± clavulanate, piperacillin-tazobactam and meropenem) to compare PK parameters reported in critically and noncritically ill neonates, children and adults, and to investigate whether allometric and maturation scaling principles could be applied to describe changes in PK parameters through life.

METHODS

A systematic review of PK studies of the three drugs was undertaken using MEDLINE and EMBASE. PK parameters and summary statistics were extracted and scaled using allometric principles to 70 kg individual for comparison. Pooled data were used to model clearance maturation and decline using a sigmoidal (Hill) function.

RESULTS

A total of 130 papers were identified. Age ranged from 29 weeks to 82 years and weight from 0.9-200 kg. PK parameters from critically ill populations were reported with wider confidence intervals than those in healthy volunteers, indicating greater PK variability in critical illness. The standard allometric size and sigmoidal maturation model adequately described increasing clearance in neonates, and a sigmoidal model was also used to describe decline in older age. Adult weight-adjusted clearance was achieved at approximately 2 years postmenstrual age. Changes in volume of distribution were well described by the standard allometric model, although amoxicillin data suggested a relatively higher volume of distribution in neonates.

CONCLUSIONS

Critical illness is associated with greater PK variability than in healthy volunteers. The maturation models presented will be useful for optimizing beta-lactam dosing, although a prospective, age-inclusive study is warranted for external validation.

Optimal infusion rate in antimicrobial therapy explosion of evidence in the last five years

Background

Sporadic studies in antimicrobial therapy have evaluated the effects of infusion rates on therapeutic and economic outcomes, and new findings may challenge the regular infusion regimen.

Methods

Focusing on studies comparing the outcomes of different infusion regimens, the relevant literature was identified by searching PubMed, Web of Science, and Scopus from January 1, 2013 to March 1, 2018. Papers were finally chosen using a PRISMA flowchart.

Results

Antimicrobials with the superiority of prolonged infusion to standard infusion in terms of efficacy and safety include meropenem, doripenem, imipenem, cefepime, ceftazidime, piperacillin/tazobactam, linezolid, and vancomycin. The strategy of concomitantly reducing total daily dose and prolonging infusion time may cause treatment failure (eg, imipenem). Extended infusion of piperacillin/tazobactam has pharmacoeconomic advantage over standard infusion. Prolonged infusion of voriconazole is inferior to standard infusion because of lower efficacy caused by pharmacokinetic changes. Comparable outcomes following standard infusion and continuous infusion were observed with norvancomycin and nafcillin. Factors determining whether prolonged infusion has a benefit over standard infusion include MIC of bacterial pathogens, bacterial density, diagnosis, disease severity, total daily dose, and renal function.

Conclusion

To maximally preserve the effectiveness of current antimicrobials, effective interventions should be implemented to enhance the application of optimal infusion strategies. For reducing nephrotoxicity, prolonged infusion of meropenem is better than conventional infusion in neonates with Gram-negative late-onset sepsis, and continuous infusion of vancomycin is superior to intermittent infusion. For increasing efficacy, prolonged or continuous infusion of time-dependent antimicrobials (eg, meropenem, doripenem, imipenem, cefepime, ceftazidime, piperacillin/tazobactam, linezolid, and vancomycin) is an optimal choice. Nevertheless, such advantages may only be demonstrated in special clinical circumstances and special populations (eg, patients with a sequential organ failure assessment (SOFA) score≥9, respiratory tract infections, urinary or intra-abdominal infections, or infections caused by less susceptible pathogens would benefit from prolonged infusion of piperacillin/tazobactam).

Clinical outcomes of prolonged infusion (extended infusion or continuous infusion) versus intermittent bolus of meropenem in severe infection: A meta-analysis

Background

Meropenem exhibits time-dependent antimicrobial activity and prolonged infusion (PI) (extended infusion or continuous infusion, EI or CI) of meropenem can better achieve pharmacodynamics target when comparing with intermittent bolus (IB). However, the clinical outcomes between two groups remain inconclusive.

Objective

To evaluate current published literatures by meta-analysis to ascertain whether PI of meropenem can improve clinical outcomes.

Methods

Medline, Cochrane database and EMBASE were searched. Randomized control trails (RCT) and observational studies which compared the clinical outcomes of PI and IB groups were included and evaluated for quality. The data of studies were extracted and meta-analysis was performed using Revman 5.3 software.

Results

Six RCTs and 4 observation studies with relatively high quality were included in this analysis. Compared to IB group, PI group had a higher clinical success rate (odd ratio 2.10, 95% confidence interval 1.31–3.38) and a lower mortality (risk ratio 0.66, 95% confidence interval 0.50–0.88). The sensitivity analysis showed the results were stable.

Conclusion

PI of meropenem was associated with a higher clinical improvement rate and a lower mortality. It is recommended for patients with severe infection or infected by less sensitive microbial.

New paradigm for rapid achievement of appropriate therapy in special populations: coupling antibiotic dose optimization rapid microbiological methods

INTRODUCTION

Some special patient populations (e.g. critically ill, burns, hematological malignancy, post-major surgery, post-major trauma) have characteristics that lead to higher rates of failure and mortality associated with infection. Choice of effective antibiotics and optimized doses are challenging in these patients that are commonly infected by multidrug-resistant pathogens. Areas covered: A review of the importance of diagnosis and the place of newer microbiological methods (e.g. whole-genome sequencing) to ensure rapid transition from empiric to directed antibiotic therapy is provided. The effects of pathophysiological changes on antibiotic pharmacokinetics are also provided. Expert opinion: Product information dosing regimens do not address the pharmacokinetic alterations that can occur in special patient populations and increase the likelihood of therapeutic failure and the emergence of bacterial resistance. Altered dosing approaches, supplemented with the use of dosing software and therapeutic drug monitoring, may be needed to ensure optimal antibiotic exposure and better therapeutic outcomes in these patients with severe infection. Dose optimization needs to be coupled with advanced microbiological techniques that enable rapid microbiological identification and characterization of resistance mechanism to ensure that maximally effective directed therapy can be chosen.

Resistance Trends and Treatment Options in Gram-Negative Ventilator-Associated Pneumonia

PURPOSE OF REVIEW

Hospital-acquired and ventilator-associated pneumonia (VAP) are frequent causes of infection among critically ill patients. VAP is the most common hospital-acquired bacterial infection among mechanically ventilated patients. Unfortunately, many of the nosocomial Gram-negative bacteria that cause VAP are increasingly difficult to treat. Additionally, the evolution and dissemination of multi- and pan-drug resistant strains leave clinicians with few treatment options. VAP patients represent a dynamic population at risk for antibiotic failure and under-dosing due to altered antibiotic pharmacokinetic parameters. Since few antibiotic agents have been approved within the last 15 years, and no new agents specifically targeting VAP have been approved to date, it is anticipated that this problem will worsen. Given the public health crisis posed by resistant Gram-negative bacteria, it is essential to establish a firm understanding of the current epidemiology of VAP, the changing trends in Gram-negative resistance in VAP, and the current issues in drug development for Gram-negative bacteria that cause VAP.

RECENT FINDINGS

Rapid identification technologies and phenotypic methods, new therapeutic strategies, and novel treatment paradigms have evolved in an attempt to improve treatment outcomes for VAP; however, clinical data supporting alternative treatment strategies and adjunctive therapies remain sparse. Importantly, new classes of antimicrobials, novel virulence factor inhibitors, and beta-lactam/beta-lactamase inhibitor combinations are currently in development. Conscientious stewardship of new and emerging therapeutic agents will be needed to ensure they remain effective well into the future.

Cost-effectiveness analysis of implementing an antimicrobial stewardship program in critical care units

AIMS

To evaluate the cost-effectiveness of antimicrobial stewardship (AS) program implementation focused on critical care units based on assumptions for the Spanish setting.

MATERIALS AND METHODS

A decision model comparing costs and outcomes of sepsis, community-acquired pneumonia, and nosocomial infections (including catheter-related bacteremia, urinary tract infection, and ventilator-associated pneumonia) in critical care units with or without an AS was designed. Model variables and costs, along with their distributions, were obtained from the literature. The study was performed from the Spanish National Health System (NHS) perspective, including only direct costs. The Incremental Cost-Effectiveness Ratio (ICER) was analysed regarding the ability of the program to reduce multi-drug resistant bacteria. Uncertainty in ICERs was evaluated with probabilistic sensitivity analyses.

RESULTS

In the short-term, implementing an AS reduces the consumption of antimicrobials with a net benefit of €71,738. In the long-term, the maintenance of the program involves an additional cost to the system of €107,569. Cost per avoided resistance was €7,342, and cost-per-life-years gained (LYG) was €9,788. Results from the probabilistic sensitivity analysis showed that there was a more than 90% likelihood that an AS would be cost-effective at a level of €8,000 per LYG.

LIMITATIONS

Wide variability of economic results obtained from the implementation of this type of AS program and short information on their impact on patient evolution and any resistance avoided.

CONCLUSIONS

Implementing an AS focusing on critical care patients is a long-term cost-effective tool. Implementation costs are amortized by reducing antimicrobial consumption to prevent infection by multidrug-resistant pathogens.