Comparing prolonged infusion to intermittent infusion strategies for beta-lactam antibiotics in patients with gram-negative bacterial infections: a systematic review and meta-analysis.

INTRODUCTION: Our objective is to determine whether prolonged infusion (PI) of beta-lactam antibiotics yields superior outcomes compared to intermittent infusion (II) in patients with Gram-Negative Bacterial (GNB) infections. METHODS: We systematically searched papers from PubMed, the Cochrane Library, Embase, and Clinicaltrials.gov, targeting mortality as the primary outcome and looking at the clinical cure rate, hospital and intensive care unit (ICU) stay lengths, antibiotic treatment duration, and mechanical ventilation (MV) duration as secondary outcomes. RESULTS: Our meta-analysis of 18 studies, including 5 randomized control trials and 13 observational studies, with a total of 3,035 patients-1,510 in the PI group and 1,525 in the II group, revealed significant findings. PI was associated with reduced mortality (RR, 0.67; 95% CI, 0.55-0.81; p = 0.001; I2 = 4.52%) and a shorter MV duration (SMD, -0.76; 95% CI, -1.37 to -0.16; p = 0.01; I2 = 87.81%) compared to II. However, no differences were found in clinical cure rates, antibiotic treatment duration, length of hospital stay, or length of ICU stay. CONCLUSIONS: The PI approach for administering beta-lactam antibiotics in patients with suspected or confirmed GNB infections may be advantageous in reducing mortality rates and the duration of MV when compared to the II strategy.

Retrospective review of intermittent and continuous infusion vancomycin for methicillin-resistant Staphylococcus aureus bacteremia.

PURPOSE: Vancomycin is commonly administered as an intermittent infusion (IIV), although vancomycin's stability at room temperature permits administration continuously over 24 h (CIV). At our institution, CIV has been the preferred infusion method for over 20 years due to ease of administration and simplicity of therapeutic drug monitoring. The purpose of this study was to examine the outcomes associated with IIV compared to CIV. METHODS: This was a retrospective study of patients who received vancomycin for MRSA bacteremia. The primary outcomes were the time to therapeutic goal and frequency of adverse drug reactions on IIV compared to CIV. Secondary outcomes evaluated all-cause readmission, relapse, and mortality 30 days after completion of therapy. RESULTS: Sixty-three patients were included. Significantly fewer patients were able to achieve a therapeutic goal on IIV compared to CIV (52.4% vs. 82.5%, p < 0.01). Patients on IIV took 3.6 days, on average, to reach the target goal, compared to 1.9 days when patients were switched to CIV (95% confidence interval, 0.48-3.04, p < 0.01). Six patients experienced adverse events on IIV, and 15 patients experienced adverse events on CIV (IIV 9.5%, CIV 23.8%, p = 0.035). One patient experienced relapse of infection, and six patients (9.5%) were readmitted 30 days after completion of therapy. There were no deaths in the cohort. CONCLUSION: For MRSA bacteremia, CIV enabled patients to achieve the AUC/MIC goal significantly faster than when patients received IIV. Furthermore, patients who were unable to achieve a therapeutic trough on IIV became therapeutic once switched to CIV.

Comparison of the Effectiveness of Prolonged Infusion and Intermittent Infusion of Meropenem in Patients With Sepsis: A Meta-Analysis.

The aim of this study was to compare the clinical effectiveness of prolonged infusion and intermittent infusion of meropenem in patients with sepsis. This meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) 2020 guidelines. PubMed, Web of Science, Scopus, and the Cochrane Library were searched without any language or time restrictions, up to September 25, 2023. The primary outcomes assessed in this meta-analysis included clinical success and all-cause mortality. Other outcomes assessed in this study encompassed the mean length of ICU stay. Total eight studies met the eligibility criteria and were included in this meta-analysis. Pooled analysis showed that the clinical success rate was significantly higher in patients receiving prolonged infusion of meropenem compared to intermittent infusion (RR: 1.49, 95% CI: 1.30 to 1.70). All-cause mortality was 24% significantly lower in patients receiving prolonged infusion of meropenem compared to intermittent infusion (RR: 0.76, 95% CI: 0.60 to 0.96). The results suggest that prolonged infusion of meropenem could be a more effective and efficient treatment for sepsis patients. However, more randomized controlled trials are needed to confirm these findings and to establish the optimal dosing and administration schedule for prolonged infusion of meropenem.

Prolonged vs short-term infusion of ß-lactam antibiotics for the treatment of febrile neutropenia: A systematic review and meta-analysis.

BACKGROUND: The optimisation of the use of ß-lactam antibiotics (BLA) via prolonged infusions in life-threatening complications such as febrile neutropenia (FN) is still controversial. This systematic review and meta-analysis aim to evaluate the efficacy of this strategy in onco-haematological patients with FN. METHODS: A systematic search was performed of PubMed, Web of Science, Cochrane, EMBASE, World Health Organization, and ClinicalTrials.gov, from database inception until December 2022. The search included randomised controlled trials (RCTs) and observational studies that compared prolonged vs short-term infusions of the same BLA. The primary outcome was all-cause mortality. Secondary outcomes were defervescence, requirement of vasoactive drugs, length of hospital stay and adverse events. Pooled risk ratios were calculated using random effects models. RESULTS: Five studies were included, comprising 691 episodes of FN, mainly in haematological patients. Prolonged infusion was not associated with a reduction in all-cause mortality (pRR 0.83; 95% confidence interval 0.47-1.48). Nor differences were found in secondary outcomes. CONCLUSIONS: The limited data available did not show significant differences in terms of all-cause mortality or significant secondary outcomes in patients with FN receiving BLA in prolonged vs. short-term infusion. High-quality RCTs are needed to determine whether there are subgroups of FN patients who would benefit from prolonged BLA infusion.

Optimizing Betalactam Clinical Response by Using a Continuous Infusion: A Comprehensive Review.

INTRODUCTION: Antimicrobial resistance is a major healthcare issue responsible for a large number of deaths. Many reviews identified that PKPD data are in favor of the use of continuous infusion, and we wanted to review clinical data results in order to optimize our clinical practice. METHODOLOGY: We reviewed Medline for existing literature comparing continuous or extended infusion to intermittent infusion of betalactams. RESULTS: In clinical studies, continuous infusion is as good as intermittent infusion. In the subset group of critically ill patients or those with an infection due to an organism with high MIC, a continuous infusion was associated with better clinical response. CONCLUSIONS: Clinical data appear to confirm those of PK/PD to use a continuous infusion in severely ill patients or those infected by an organism with an elevated MIC, as it is associated with higher survival rates. In other cases, it may allow for a decrease in antibiotic daily dosage, thereby contributing to a decrease in overall costs.

Factors associated with meropenem pharmacokinetic/pharmacodynamic target attainment in septic critically ill patients treated with extended intermittent infusion or continuous infusion.

OBJECTIVES: The use of extended intermittent infusion (EII) or continuous infusion (CI) of meropenem is recommended in intensive care unit (ICU) patients, but few data comparing these two options are available. This retrospective cohort study was conducted between 1 January 2019 and 31 March 2020 in a teaching hospital ICU. It aimed to determine the meropenem plasma concentrations achieved with CI and EII. METHODS: The study included septic patients treated with meropenem who had one or more meropenem plasma trough (Cmin) or steady-state concentration (Css) measurement(s), as appropriate. It then assessed the factors independently associated with attainment of the target concentration (Cmin or Css ≥ 10 mg/L) and the toxicity threshold (Cmin or Css ≥ 50 mg/L) using logistic regression models. RESULTS: Among the 70 patients analysed, the characteristics of those treated with EII (n = 33) and CI (n = 37) were balanced with the exception of estimates glomerular filtration rate (eGFR): median 30 mL/min/m2 (IQR 30, 84) vs. 79 mL/min/m2 (IQR 30, 124). Of the patients treated with EII, 21 (64%) achieved the target concentration, whereas 31 (97%) of those treated with CI achieved it (P < 0.001). Factors associated with target attainment were: CI (OR 16.28, 95% CI 2.05-407.5), daily dose ≥ 40 mg/kg (OR 12.23, 95% CI 1.76-197.0; P = 0.03) and eGFR (OR 0.98, 95% CI 0.97-0.99; P = 0.02). Attainment of toxicity threshold was associated with daily dose > 70 mg/kg (OR 35.5, 95% CI 5.61-410.3; P < 0.001). CONCLUSION: The results suggest the use of meropenem CI at 40-70 mg/kg/day, particularly in septic ICU patients with normal or augmented renal clearance.

Pharmacokinetic/Pharmacodynamic Determination of Systemic MIC Breakpoints for Intermittent, Extended, and Continuous Infusion Dosage Regimens of Mecillinam.

Intravenous mecillinam has been used for the treatment of urosepsis at several dosing regimens, including a dose of 1,000 mg three times a day (TID). In the current pharmacokinetic/pharmacodynamic (PK/PD) study, we analyzed intermittent, extended, and continuous infusion regimens of mecillinam to provide dosage recommendations to treat infections caused by Enterobacterales exhibiting relatively higher mecillinam MICs than the wild-type strains. Monte Carlo simulation studies indicated that regimens of 1,000 mg TID and 1,000 to 1,200 mg four times a day (QID) are efficacious against wild-type and extended-spectrum ß-lactamase-producing Enterobacterales, respectively. Prolonged infusion regimens (extended and continuous) could cover carbapenemase producers with a higher range of MICs (2 to 8 mg/L). IMPORTANCE Previous studies have shown that intravenous mecillinam might be suitable for treatment of urosepsis. Since multidrug-resistant Enterobacterales are common pathogens in such infections, an effort was made to delineate intermittent, extended, and continuous infusion regimens that could cover pathogens exhibiting relatively higher mecillinam MICs than the wild-type strains. Our PK/PD analysis has shown that mecillinam might be considered a valuable therapeutic option for the treatment of systemic infections caused by extended-spectrum ß-lactamase- and carbapenemase-producing Enterobacterales exhibiting mecillinam MICs up to 8 mg/L.

The clinical and paraclinical effectiveness of four-hour infusion vs. half-hour infusion of high-dose ampicillin-sulbactam in treatment of critically ill patients with sepsis or septic shock: An assessor-blinded randomized clinical trial.

PURPOSE: This study was conducted to determine whether critically ill patients admitted to the intensive care unit (ICU) with sepsis and septic shock may benefit from extended infusion of ampicillin/sulbactam compared with those receiving intermittent infusion. MATERIAL AND METHODS: This randomized assessor-blinded clinical trial was conducted in the ICUs of Nemazee and Shahid Rajaee hospital, Shiraz, Iran, from August 2019 to August 2021. The participants randomly received 9 g Ampicillin/Sulbactam every 8 h by either extended (infused over 4 h) or intermittent (infused over 30 min) intravenous infusion if their estimated glomerular filtration rate based on Cockrorft-Gault formula was higher than 60 ml/min. RESULTS: Totally, 136 patients were enrolled and allocated to the intervention and control groups, each with 68 patients. Clinical cure was significantly higher in the extended group (P = 0.039), but ICU and hospital length of stay did not differ between the groups (P = 0.87 and 0.83, respectively). The ICU (P = 0.031) and hospital (P = 0.037) mortality rates in the extended infusion group were significantly lower than those in the intermittent infusion group. CONCLUSION: These data should be replicated in larger clinical trials before providing any recommendation in favor of this method of administration in clinical practice.

Efficacy and safety of continuous pump versus intermittent infusion of amphotericin B in the treatment of invasive fungal infection：a meta-analysis / 中国药房

OBJECTIVE To compare efficacy and safety of continuous pump versus intermittent infusion of amphotericin B in the treatment of invasive fungal infection， and to provide evidence-based reference for clinical treatment. METHODS Retrieved from PubMed， the Cochrane Library， Web of Science， Embase， Wanfang， CNKI， CBM and VIP database， randomized controlled trial （RCT） and cohort study about 24 h continuous pump （trial group） versus intermittent infusion （control group） of amphotericin B were collected from the inception to Jan. 2023. After literature screening and data extraction， the quality of RCT was evaluated with modified Jadad scale， and the quality of cohort study was evaluated with Newcastle-Ottawa scale. Meta-analysis and sensitivity analysis were performed by using RevMan 5.4 software. RESULTS A total of 7 literature were included， involving 1 RCT and 6 cohort studies with a total of 767 patients. The results of meta-analysis showed that the clinical effective rate [RR＝1.44， 95%CI （1.13，1.83）， P＝0.003] of trial group was significantly higher than that of control group， and all-cause mortality rate [RR＝0.37， 95%CI（0.19，0.72），P＝0.003] and the incidence rate of infusion reaction [RR＝0.28，95%CI（0.18，0.43）， P＜0.000 01] were significantly lower than control group； there was no statistical significance in the incidence rate of renal impairment between 2 groups [RR＝0.71，95%CI（0.45，1.11），P＝0.13] . The sensitivity analysis results showed that the results obtained in this study were robust. CONCLUSIONS The efficacy and safety of 24 h continuous pump of amphotericin B are better than those of intermittent infusion in the treatment of invasive fungal infection.

Comparison of Continuous Infusion of Ropivacaine and Fentanyl With Intermittent Bolus Doses of Ropivacaine and Fentanyl for Epidural Labor Analgesia: A Randomized Open-Label Study.

Background The purpose of this study was to compare the efficacy of continuous epidural infusion with intermittent bolus doses for labour analgesia using ropivacaine 0.2% and opioids. Methods In this study, 70 primigravida patients were randomly divided into two groups of 35 each. Both groups received a loading dose of 10ml of 0.2% ropivacaine and 1µg/ml fentanyl in 5ml incremental doses while monitoring blood pressure and heart rate. Subsequently, Group I received a continuous epidural infusion of 0.2% ropivacaine with fentanyl at 10ml/hr, while Group II received 10 ml of 0.2% ropivacaine with fentanyl in bolus form every hour manually, with the first dose given after one hour of the initial loading dose. A rescue bolus dose of 5ml of 0.2% ropivacaine was given in both groups when they complained of breakthrough pain (VAS score >3). An additional 5ml bolus dose was given in both groups at the time of crowning. The blood pressure, heart rate, and severity of pain using the visual analogue scale (VAS) were assessed. Total drug volume utilized, the number of bolus doses, duration of the first and second stage of labour, rate of instrumental delivery and cesarean section, and neonatal Apgar scores were also recorded. Results The total volume of drugs consumed and the number of boluses required for breakthrough pain were both significantly lower in Group II. There was a similar decrease in hemodynamic parameters (systolic blood pressure, diastolic blood pressure, and mean arterial pressure) from baseline in both the groups with no significant difference between them. The onset of analgesia was significantly faster in Group I with both groups achieving optimum analgesia (VAS ≤ 3) within 20 minutes of the loading dose. Maternal motor blockade scores, the duration of the first and second stage of labour, the rate of instrumental delivery, cesarean section, and neonatal Apgar scores, did not show any statistically significant difference between the two groups. Conclusion Both techniques, i.e. continuous epidural infusion and intermittent epidural boluses are effective for providing labour analgesia. But consumption of drugs and episodes of breakthrough pain was higher in the continuous infusion group (Group I).

Continuous infusion versus intermittent infusion of vancomycin in critically ill patients undergoing continuous venovenous hemofiltration: a prospective interventional study.

BACKGROUND: A prospective interventional study comparing outcomes in critically ill patients receiving intermittent infusion (II) or continuous infusion (CI) of vancomycin during continuous venovenous hemofiltration (CVVH) is lacking. The objective of this study was to compare the pharmacokinetic/pharmacodynamics (PK/PD) target attainment, therapeutic efficacy and safety among critically ill patients who received CI or II of vancomycin in a prospective interventional trial and to explore the correlations of effluent flow rate (EFR) with PK/PD indices. METHODS: This prospective interventional study was conducted in two independent intensive care units (ICUs) from February 2021 to January 2022. Patients in one ICU were assigned to receive CI (intervention group) of vancomycin, whereas patients in the other ICU were assigned to receive II regimen (control group). The primary outcome was to compare the PK/PD target attainment, including target concentration and target area under the curve over 24 h to minimum inhibitory concentration (AUC24/MIC). RESULTS: Overall target attainment of PK/PD indices was higher with CI compared with II, irrespective of target concentration (78.7% vs. 40.5%; P < 0.05) or AUC24/MIC (53.2% vs. 28.6%; P < 0.05). There were no significant differences in clinical success (72.2% vs. 50.0%; P = 0.183) and microbiological success (83.3% vs. 75.0%, P = 0.681) between the patients treated with CI or II of vancomycin. Adverse reactions occurred at similar rates (0.0% vs. 4.4%; P = 0.462), and mortality between the two modalities was also not significant different (21.7% vs. 17.9%; P = 0.728). Correlation analysis showed a weak to moderately inverse correlation of EFR with observed concentration (r = - 0.3921, P = 0.01) and AUC24/MIC (r = - 0.3811, P = 0.013) in the II group, whereas the correlation between EFR and observed concentration (r = - 0.5711, P < 0.001) or AUC24/MIC (r = - 0.5458, P < 0.001) in the CI group was stronger. CONCLUSION: As compared to II, CI of vancomycin in critically ill patients undergoing CVVH was associated with improved attainment of PK/PD indices. Furthermore, the inverse correlation of PK/PD indices with EFR was stronger among patients treated with CI of vancomycin. Trial registration The trial was registered in the Chinese clinical trial registration center (21/01/2021-No. ChiCTR2100042393).

Pharmacokinetic/Pharmacodynamic Target Attainment of Vancomycin, at Three Reported Infusion Modes, for Methicillin-Resistant Staphylococcus aureus (MRSA) Bloodstream Infections in Critically Ill Patients: Focus on Novel Infusion Mode.

Objective: The study aimed to evaluate and compare the pharmacokinetic/pharmacodynamic (PK/PD) exposure to vancomycin in the novel optimal two-step infusion (OTSI) vs. intermittent infusion (II) vs. continuous infusion (CI) mode, for MRSA bloodstream infections occurring in critical patients. Methods: With PK/PD modeling and Monte Carlo simulations, the PK/PD exposure of 15 OTSI, 13 II, and 6 CI regimens for vancomycin, at 1, 2, 3, 4, 5, and 6 g daily dose, was evaluated. Using the Monte Carlo simulations, the vancomycin population PK parameters derived from critical patients, the PD parameter for MRSA isolates [i.e., minimum inhibitory concentration (MIC)], and the dosing parameters of these regimens were integrated into a robust mdel of vancomycin PK/PD index, defined as a ratio of the daily area under the curve (AUC0-24) to MIC (i.e., AUC0-24/MIC), to estimate the probability of target attainment (PTA) of these regimens against MRSA isolates with an MIC of 0.5, 1, 2, 4, and 8 mg/L in patients with varying renal function. The PTA at an AUC0-24/MIC ratio of >400, 400-600, and >600 was estimated. A regimen with a PTA of ≥90% at an AUC0-24/MIC ratio of 400-600, which is supposed to maximize both efficacy and safety, was considered optimal. Results: At the same daily dose, almost only the OTSI regimens showed a PTA of ≥90% at an AUC0-24/MIC ratio of 400-600, and this profile seems evident especially in patients with creatinine clearance (CLcr) of ≥60 ml/min and for isolates with an MIC of ≤2 mg/L. However, for patients with CLcr of <60 ml/min and for isolates with an MIC of ≥4 mg/L, the II regimens often displayed a higher or even ≥90% PTA at an AUC0-24/MIC ratio of >400 and of >600. The CI regimens frequently afforded a reduced PTA at an AUC0-24/MIC ratio of >400 and of >600, regardless of CLcr and MIC. Conclusions: The data indicated that the OTSI regimens allowed preferred PK/PD exposure in terms of both efficacy and safety, and thus should be focused more on, especially in patients with CLcr of ≥60 ml/min and for isolates with an MIC of ≤2 mg/L.

Linezolid Administration to Critically Ill Patients: Intermittent or Continuous Infusion? A Systematic Literature Search and Review.

A judicious antibiotic therapy is one of the challenges in the therapy of critically ill patients with sepsis and septic shock. The pathophysiological changes in these patients significantly alter the antibiotic pharmacokinetics (PK) and pharmacodynamics (PD) with important consequences in reaching the therapeutic targets or the risk of side effects. The use of linezolid, an oxazolidinone antibiotic, in intensive care is such an example. The optimization of its therapeutic effects, administration in intermittent (II) or continuous infusion (CI) is gaining increased interest. In a systematic review of the main databases, we propose a detailed analysis of the main PK/PD determinants, their relationship with the clinical therapeutic response and the occurrence of adverse effects following II or CI of linezolid to different classes of critically ill patients or in Monte Carlo simulations.

Continuous Versus Intermittent Linezolid Infusion for Critically Ill Patients with Hospital-Acquired and Ventilator-Associated Pneumonia: Efficacy and Safety Challenges.

High variability of linezolid blood concentrations with partial subtherapeutic levels was observed in critically ill patients who received a standard intravenous dose of linezolid, contributing to drug resistance and toxicity. Continuous infusions of linezolid have been suggested as an alternative and provide good serum and alveolar levels without fluctuations in trough concentration. This study aimed to assess the effectiveness and safety of continuous linezolid infusion versus the standard regimen in critically ill patients. A prospective randomized controlled study was conducted on 179 patients with nosocomial pneumonia. Patients were randomized into two groups. The first group received IV linezolid 600 mg twice daily, while the second group received 600 mg IV as a loading dose, followed by a continuous infusion of 1200 mg/day (50 mg/h) for at least 8−10 days. The continuous infusion group showed a higher clinical cure rate than the intermittent infusion group (p = 0.046). Furthermore, efficacy was proven by greater improvement of P/F ratio (p = 0.030) on day 7 of treatment, a lower incidence of developing sepsis after beginning treatment (p = 0.009), and a shorter time to reach clinical cure (p < 0.001). Hematological parameters were also assessed during the treatment to evaluate the safety between the two groups. The incidence of thrombocytopenia was significantly lower in the continuous infusion group than in the intermittent infusion group. In addition, a stepwise logistic regression model revealed that the intermittent infusion of linezolid was significantly associated with thrombocytopenia (OR =4.128; 95% CI = 1.681−10.139; p =0.001). The current study is the first to assess the clinical aspects of continuous infusion of linezolid beyond pharmacokinetic studies. Continuous infusion of linezolid outperforms intermittent delivery in safety and improves clinical effectiveness in critically ill patients with Gram-positive nosocomial pneumonia.

Antibacterial Activity and Optimal Treatment of Ceftazidime-Avibactam and Aztreonam-Avibactam Against Bloodstream Infections Caused by Carbapenem-Resistant Klebsiella pneumoniae.

Objectives: This work was to investigate the activity and optimal treatments of ceftazidime-avibactam (CZA) and aztreonam-avibactam (AZA) against bloodstream infections caused by carbapenem resistant Klebsiella pneumoniae (BSIs-CRKP). Methods: A total of 318 nonduplicate BSIs-CRKP isolates were collected from Blood Bacterial Resistant Investigation Collaborative System (BRICS) program. The minimum inhibitory concentration (MIC) of CZA and AZA were determined by agar dilution method. Carbapenemase genes and multilocus sequence typing were amplified by PCR. Monte Carlo simulation (MCS) was conducted to calculate cumulative fraction of response (CFR) of different CZA or AZA administrations. Results: The MIC90 of CZA and AZA were 128/4 and 1/4 mg/L, respectively. There are 87.4 and 3.5% isolates carried bla KPC-2 and bla NDM-1. A total of 68 ST types were identified and 29 novel ST types. ST11 accounted for 66.6%. Further MCS showed CFR of CZA using two-step infusion therapy (rapid first-step 0.5 h infusion and slow second-step 3 h infusion, TSIT) (2.5 g 0.5 h, 3.75 g every 8 h with 3 h infusion and 3.75 g 0.5 h, 2.5 g every 8 h with 3 h infusion) was above 89%. The CFR of AZA with TSIT was above 96%. Conclusion: TSIT with sufficient pharmacokinetic conditions could be useful for enhancing the therapeutic efficacy of CZA and AZA against BSIs-CRKP.

Continuous infusion versus intermittent infusion vancomycin in a burn center intensive care unit.

BACKGROUND: Vancomycin is a common and critical drug for empiric antimicrobial therapy in the infected burn patient. However, profound physiologic changes may impede the clinical effectiveness and amplify the potential nephrotoxicity of vancomycin. METHODS: This was a retrospective cohort study at a large academic medical center and regional burn center. Patients with ≥10% total body surface area burn that received intravenous vancomycin were considered for study inclusion. Patients were assigned to the intermittent infusion or continuous infusion cohort if they received vancomycin for ≥48 h with ≥1 documented vancomycin serum concentration. The target steady state drug level for continuous infusion was 17-22 mg/L. The target steady state trough drug level for intermittent infusion was 15-20 mg/L. The primary efficacy and safety outcomes were time to therapeutic drug level and nephrotoxicity respectively. RESULTS: Thirty continuous infusion subjects with 88 plasma drug levels and thirty intermittent infusion subjects with 80 plasma drug levels were analyzed within the study period. There was a significant difference in the number of subjects that achieved a plasma vancomycin level within the target range during the course of therapy (73.3% for continuous infusion vs. 26.7% for intermittent infusion, p = 0.0003). The time to therapeutic level was 3.90 days for continuous infusion and 5.22 days for intermittent infusion (p = 0.0393). Nephrotoxicity occurred less frequently in the continuous infusion cohort (23.3% vs. 53.8%). CONCLUSION: Continuous infusion vancomycin was associated with more rapid attainment of target levels and a lower rate of nephrotoxicity.

ß-lactam dosing strategies: Think before you push.

OBJECTIVES: There has been interest in administering cefepime, a ß-lactam antibiotic, via intravenous push (IVP) as a means to improve time to first-dose antibiotic and reduce cost; however, the downstream impacts on antibiotic exposure and pharmacodynamic efficacy need to be further evaluated. METHODS: This study used a population pharmacokinetic model for cefepime and simulated exposures to predict the pharmacodynamic (PD) effect for cefepime regimens administered via IVP or 30-minute intermittent infusion in adults with different renal functions. FDA-approved adult dosages of 1-2 g every 8 or 12 hours were compared. This study aimed to compare the absolute difference in pharmacodynamic probability of target attainment (PTA) between IVP and intermittent infusion, defined as free cefepime concentrations above organism MIC for ≥ 70% of the time. RESULTS: At MICs of 0.25-0.5 mg/L, absolute differences in PTA were observed, with a reduction as great as 2.3% (89% to 86.7% for 30-minute intermittent infusion and IVP, respectively). At MICs of 1-4 mg/L, 30-minute intermittent infusion and IVP exhibited PTA differences as great as 5.4%, from 89.4% to 84%, respectively. At MICs of ≥8 mg/L, similar absolute differences existed; however, no regimen achieved a PTA >70%. Across renal function strata of 60, 100 and 140 mL/minute (within the same dosing group and MICs), better renal function lowered PTAs. CONCLUSIONS: Simulations demonstrated that IVP cefepime resulted in lower PTAs than traditional intermittent infusion among a subset of elevated MICs. Clinicians should exercise caution in IVP strategy, as unintended clinical consequences are possible.

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.

Evaluation of Meropenem Extended Versus Intermittent Infusion Dosing Protocol in Critically Ill Patients.

Extended infusion (EI) administration of ß-lactams can improve target attainment in critically ill patients with altered pharmacokinetics/pharmacodynamics. To optimize meropenem dosing in patients with severe sepsis/septic shock, our Antimicrobial Stewardship Program implemented a EI meropenem (EIM) protocol in an 18-bed Medical Intensive Care Unit in March 2014. In this retrospective study, we compared intensive care unit (ICU) mortality and clinical response in patients who received meropenem for ≥72 hours administered per EIM protocol of 1 g over 3 hours every 8 hours versus intermittent infusion (IIM) protocol of 500 mg over 30 minutes every 6 hours. Age, weight, comorbidities, severity of illness, and vasopressor use were comparable between groups (EIM protocol n = 52, IIM protocol n = 96). The IIM protocol group had higher rates of renal dose adjustment at meropenem initiation. Among 56 identified gram-negative (GN) pathogens, 94% had meropenem minimal inhibitory concentration ≤0.25 mg/L. The ICU mortality was lower (19 vs 37%; P = .032) and clinical response was higher (83% vs 46%; P < .01) in the EIM protocol versus IIM protocol group. Total vasopressor days were shorter (2 vs 3 days; P = .038), and white blood cell normalization rate was higher (87% vs 51%; P < .01) in the EIM protocol versus IIM protocol group. There was no difference in days of mechanical ventilation, duration of therapy, and ICU stay. The IIM protocol was also identified as an independent risk factor associated with ICU mortality (hazard ratio: 3.653, 95% confidence interval: 1.689-7.981; P = .001) after adjusting for Sequential Organ Failure Assessment score. In this cohort of patients with severe sepsis/septic shock and highly susceptible GN pathogens, there was improved mortality and clinical response in the EIM protocol group.