Similar Piperacillin/Tazobactam Target Attainment in Obese versus Nonobese Patients despite Differences in Interstitial Tissue Fluid Pharmacokinetics.
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ABSTRACT:
SUBMITTER: Busse D
PROVIDER: S-EPMC8464843 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:The treatment of infections in critically ill obese and morbidly obese patients is challenging because of the combined physiological changes that result from obesity and critical illness. The aim of this study was to describe the population pharmacokinetics of piperacillin in a cohort of critically ill patients, including obese and morbidly obese patients. Critically ill patients who received piperacillin-tazobactam were classified according to their body mass index (BMI) as nonobese, obese, and morbidly obese. Plasma samples were collected, and piperacillin concentrations were determined by a validated chromatographic method. Population pharmacokinetic analysis and Monte Carlo dosing simulations were performed using Pmetrics software. Thirty-seven critically ill patients (including 12 obese patients and 12 morbidly obese patients) were enrolled. The patients' mean ± standard deviation age, weight, and BMI were 50 ± 15 years, 104 ± 35 kg, and 38.0 ± 15.0 kg/m2, respectively. The concentration-time data were best described by a two-compartment linear model. The mean ± SD parameter estimates for the final covariate model were a clearance of 14.0 ± 7.1 liters/h, a volume of distribution of the central compartment of 49.0 ± 19.0 liters, an intercompartmental clearance from the central compartment to the peripheral compartment of 0.9 ± 0.6 liters · h-1, and an intercompartmental clearance from the peripheral compartment to the central compartment of 2.3 ± 2.8 liters · h-1 A higher measured creatinine clearance and shorter-duration infusions were associated with a lower likelihood of achieving therapeutic piperacillin exposures in patients in all BMI categories. Piperacillin pharmacokinetics are altered in the presence of obesity and critical illness. As with nonobese patients, prolonged infusions increase the likelihood of achieving therapeutic concentrations.
| S-EPMC5328553 | biostudies-other
Project description:Background and objectiveStandard piperacillin-tazobactam (P-T) dosing may be suboptimal in obesity, but high-dose regimens have not been studied. We prospectively evaluated the pharmacokinetics and pharmacodynamics of standard- and high-dose P-T in obese adult inpatients.MethodsThose receiving standard-dose P-T with BMI ≥ 30 kg/m2 weighing 105-139 kg or ≥ 140 kg were given up to 6.75 g or 9 g every 6 h, respectively. Patients were monitored closely for safety. Elimination phase blood samples were drawn for 28 patients on standard and high doses to calculate the pharmacokinetic values using a one-compartment model. The likelihood of pharmacodynamic target attainment (100% fT > 16/4 mg/L) on various P-T regimens was calculated using each patient's own pharmacokinetic values.ResultsPiperacillin and tazobactam half-lives ranged from 0.5-10.6 to 0.9-15.0 h, while volumes of distribution ranged from 13.6-54.8 to 11.5-60.1 L, respectively. Predicted dose requirements for target attainment ranged from 2.25 g every 6 h in hemodialysis patients to a 27 g/24-h continuous infusion in a patient with a short P-T half-life. An amount of 4.5 g every 6 h would have met the target for only 1/12 (8%) patients with creatinine clearance ≥ 80 mL/min and 13/28 (46%) for all enrolled patients. One patient (3%) experienced an adverse event deemed probably related to high-dose P-T.ConclusionSome patients required high P-T doses for target attainment, but dosing requirements were highly variable. Doses up to 6.75 g or 9 g every 6 h may be tolerable; however, studies are needed to see if high dosing, prolonged infusions, or real-time therapeutic drug monitoring improves outcomes in obese patients. CLINICAL TRIAL REGISTRATION (CLINICALTRIALS.GOV): NCT01923363.
| S-EPMC8093170 | biostudies-literature
Project description:Although obesity is prevalent among children in the United States, pharmacokinetic (PK) data for obese children are limited. Clindamycin is a commonly used antibiotic that may require dose adjustment in obese children due to its lipophilic properties. We performed a clindamycin population PK analysis using data from three separate trials. A total of 420 samples from 220 children, 76 of whom had a body mass index greater than or equal to the 95th percentile for age, were included in the analysis. Compared to other metrics, total body weight (TBW) was the most robust measure of body size. The final model included TBW and a sigmoidal maturation relationship between postmenstrual age (PMA) and clearance (CL): CL (liters/hour) = 13.8 × (TBW/70)0.75 × [PMA2.83/(39.52.83+PMA2.83)]; volume of distribution (V) was associated with TBW, albumin (ALB), and alpha-1 acid glycoprotein (AAG): V (liters) = 63.6 × (TBW/70) × (ALB/3.3)-0.83 × (AAG/2.4)-0.25 After accounting for differences in TBW, obesity status did not explain additional interindividual variability in model parameters. Our findings support TBW-based dosing for obese and nonobese children.
| S-EPMC5365720 | biostudies-literature
Project description: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.
| S-EPMC6811421 | biostudies-literature
Project description:Background and objectivesCurrent recommendations for piperacillin-tazobactam dosing in patients receiving continuous renal replacement therapy originate from studies with relatively few patients and lower continuous renal replacement therapy doses than commonly used today. This study measured the pharmacokinetic and pharmacodynamic characteristics of piperacillin-tazobactam in patients treated with continuous renal replacement therapy using contemporary equipment and prescriptions.Design, setting, participants, & measurementsA multicenter prospective observational study in the intensive care units of two academic medical centers was performed, enrolling patients with AKI or ESRD receiving piperacillin-tazobactam while being treated with continuous renal replacement therapy. Pregnant women, children, and patients with end stage liver disease were excluded from enrollment. Plasma and continuous renal replacement therapy effluent samples were analyzed for piperacillin and tazobactam levels using HPLC. Pharmacokinetic and pharmacodynamic parameters were calculated using standard equations. Multivariate analyses were used to examine the association of patient and continuous renal replacement therapy characteristics with piperacillin pharmacokinetic parameters.ResultsForty-two of fifty-five subjects enrolled had complete sampling. Volume of distribution (median=0.38 L/kg, intraquartile range=0.20 L/kg) and elimination rate constants (median=0.104 h(-1), intraquartile range=0.052 h(-1)) were highly variable, and clinical parameters could explain only a small fraction of the large variability in pharmacokinetic parameters. Probability of target attainment for piperacillin was 83% for total drug but only 77% when the unbound fraction was considered.ConclusionsThere is significant patient to patient variability in pharmacokinetic/pharmacodynamic parameters in patients receiving continuous renal replacement therapy. Many patients did not achieve pharmacodynamic targets, suggesting that therapeutic drug monitoring might optimize therapy.
| S-EPMC3302674 | biostudies-literature
Project description:We have previously demonstrated the pharmacokinetic-pharmacodynamic (PK-PD) index best associated with the efficacy of tazobactam when used in combination with ceftolozane to be the percentage of the dosing interval during which tazobactam concentrations remained above a threshold value (%time>threshold). Using anin vitroinfection model and the same isogenic CTX-M-15-producingEscherichia colitriplet set genetically engineered to transcribe different levels ofblaCTX-M-15, herein we describe dose fractionation studies designed to evaluate the PK-PD index associated with tazobactam efficacy, when given in combination with piperacillin, and the impact of the presence of a different ?-lactam agent, or differentblaCTX-M-15transcription levels, on the magnitude of the tazobactam PK-PD index necessary for efficacy. The recombinant strains demonstrated piperacillin MIC values of 128, >256, and >256 ?g/ml for the low-, moderate-, and high-level CTX-M-15-producingE. colistrains, respectively. The MIC value for piperacillin in the presence of 4 ?g/ml of tazobactam was 2 ?g/ml for all three strains. The PK-PD index associated with tazobactam efficacy was confirmed to be %time>threshold, regardless of ?-lactamase transcription (r(2)= 0.839). The tazobactam concentration thresholds, however, changed with the CTX-M-15 transcription level and were 0.25, 0.5, and 2 ?g/ml for the low-, moderate-, and high-level CTX-M-15-producing strains, respectively (r(2)= 0.921, 0.773, and 0.875, respectively). The %time>threshold values for tazobactam necessary for net bacterial stasis and a 1- and 2-log10-unit CFU/ml decrease from baseline at 24 h were 44.9, 62.9, and 84.9%, respectively. In addition to verifying our previous study results, these results also demonstrated that the magnitude of bacterial-cell killing associated with a ?-lactam-?-lactamase inhibitor combination is dependent on the amount of ?-lactamase produced. These data provide important information for the development of ?-lactam-?-lactamase inhibitor combination agents.
| S-EPMC4808219 | biostudies-literature
Project description:BACKGROUND:Piperacillin, in combination with tazobactam, is frequently used in infants for treating nosocomial infections, although safety data in this population are limited. Electronic health record (EHR) data can be used to evaluate drug safety in infants, but measures of drug exposure are lacking. METHODS:To relate simulated piperacillin exposure with adverse events (AEs) in infants using EHR data, we identified infants discharged from 333 neonatal intensive care units managed by the Pediatrix Medical Group between 1997 and 2012. Using a previously published population pharmacokinetic model in the target population, we simulated piperacillin steady state area under the concentration versus time curve from zero to ? (AUCss,0-?) and steady state maximal drug concentration (Cmaxss). Next, we used multivariable logistic regression to evaluate the association between simulated AUCss,0-? and Cmaxss with clinical AEs (seizure and rash) and laboratory AEs controlling for gestational age. The odds ratios (95% confidence intervals) comparing the third versus the first tertiles for AUCss,0-? and Cmaxss were reported. RESULTS:We identified 746 infants with a median (interquartile range) gestational age of 30 weeks (26-33) and postnatal age of 11 days (6-25). The median (interquartile range) piperacillin dose was 225?mg/kg/d (176-300). No significant associations were found between simulated piperacillin exposure (AUCss,0-? and Cmaxss) and clinical and laboratory AEs. CONCLUSIONS:We found no associations between predicted piperacillin exposures and the occurrence of AEs. This study confirms the feasibility of using population pharmacokinetics and EHR to relate drug exposure with safety.
| S-EPMC5555808 | biostudies-literature
Project description:Infection is the most common cause of death in severe AKI, but many patients receiving continuous RRT do not reach target antibiotic concentrations in plasma. Extended infusion of ?-lactams is associated with improved target attainment in critically ill patients; thus, we hypothesized that extended infusion piperacillin-tazobactam would improve piperacillin target attainment compared with short infusion in patients receiving continuous RRT.We conducted an institutional review board-approved observational cohort study of piperacillin-tazobactam pharmacokinetics and pharmacodynamics in critically ill patients receiving continuous venovenous hemodialysis and hemodiafiltration at three tertiary care hospitals between 2007 and 2015. Antibiotic concentrations in blood and/or dialysate samples were measured by liquid chromatography, and one- and two-compartment pharmacokinetic models were fitted to the data using nonlinear mixed effects regression. Target attainment for piperacillin was defined as achieving four times the minimum inhibitory concentration of 16 ?g/ml for >50% of the dosing cycle. The probabilities of target attainment for a range of doses, frequencies, and infusion durations were estimated using a Monte Carlo simulation method. Target attainment was also examined as a function of patient weight and continuous RRT effluent rate.Sixty-eight participants had data for analysis. Regardless of infusion duration, 6 g/d piperacillin was associated with ?45% target attainment, whereas 12 g/d was associated with ?95% target attainment. For 8 and 9 g/d, target attainment ranged between 68% and 85%. The probability of target attainment was lower at higher effluent rates and patient weights. For all doses, frequencies, patient weights, and continuous RRT effluent rates, extended infusion was associated with higher probability of target attainment compared with short infusion.Extended infusions of piperacillin-tazobactam are associated with greater probability of target attainment in patients receiving continuous RRT.
| S-EPMC4974884 | biostudies-other
Project description:Tedizolid is a novel oxazolidinone antimicrobial administered in its prodrug form, tedizolid phosphate, as a fixed once-daily dose. The pharmacokinetics of tedizolid has been studied in a relatively small proportion of morbidly obese (body mass index [BMI] of ?40 kg/m(2)) adults through population analyses with sparse sampling. The current study compared the intensively sampled plasma pharmacokinetics of tedizolid phosphate and tedizolid in 9 morbidly obese and 9 age-, sex-, and ideal body weight-matched nonobese (BMI, 18.5 to 29.9 kg/m(2)) healthy adult (18 to 50 years of age) volunteers after administration of a single intravenous dose of tedizolid phosphate. The median (range) weights were 72.6 kg (58.9 to 89.5 kg) and 117 kg (102 to 176 kg) for the mostly female (77.8%) nonobese and morbidly obese adults, respectively. Tedizolid phosphate concentrations were below the limit of quantitation in a majority of subjects after the 2-h time point. The tedizolid median (range) maximum concentration of drug in plasma (Cmax) and area under the concentration-time curve from 0 h to infinity (AUC0-?) were 2.38 (1.28 to 3.99) mg/liter and 26.3 (18.4 to 43.2) h · mg/liter, respectively, for morbidly obese subjects, and these were nonsignificantly different (P ? 0.214) from the values for nonobese subjects. Similarly, the volumes of distribution (Vz) (P = 0.110) and clearance (CL) values (P = 0.214) were comparable between groups. Nearly identical (P = 0.953) median tedizolid half-lives of approximately 12 h were observed for both groups. Tedizolid Vz and CL scaled with body weight, but not proportionately. The small and nonsignificant differences in tedizolid AUC0-? values between morbidly obese and nonobese subjects suggest that dose modification is not necessary for morbidly obese adults. (This study has been registered at ClinicalTrials.gov under number NCT02342418.).
| S-EPMC4958168 | biostudies-literature
Project description:The aim of this study was to develop a population pharmacokinetic model for piperacillin (PIPC)/tazobactam (TAZ) in late elderly patients with pneumonia and to optimize the administration planning by applying pharmacokinetic/pharmacodynamic (PK/PD) criteria. PIPC/TAZ (total dose of 2.25 or 4.5 g) was infused intravenously three times daily to Japanese patients over 75 years old. The plasma concentrations of PIPC and TAZ were determined using high-performance liquid chromatography and modeled using the NONMEM program. PK/PD analysis with a random simulation was conducted using the final population PK model to estimate the probability of target attainment (PTA) profiles for various PIPC/TAZ-regimen-minimum-inhibitory-concentration (MIC) combinations. The PTAs for PIPC and TAZ were determined as the fraction that achieved at least 50% free time > MIC and area under the free-plasma-concentration-time curve over 24 h ? 96 ?g h/mL, respectively. A total of 18 cases, the mean age of which was 86.5 ± 6.0 (75-101) years, were investigated. The plasma-concentration-time profiles of PIPC and TAZ were characterized by a two-compartment model. The parameter estimates for the final model, namely the total clearance, central distribution volume, peripheral distribution volume, and intercompartmental clearance, were 4.58 + 0.061 × (CLcr - 37.4) L/h, 5.39 L, 6.96 L, and 20.7 L/h for PIPC, and 5.00 + 0.059 × (CLcr - 37.4) L/h, 6.29 L, 7.73 L, and 24.0 L/h for TAZ, respectively, where CLcr is the creatinine clearance. PK/PD analysis using the final model showed that in drug-resistant strains with a MIC > 8 ?g/mL, 4.5 g of PIPC/TAZ every 6 h was required, even for the patients with a CLcr of 50-60 mL/min. The population PK model developed in this study, together with MIC value, can be useful for optimizing the PIPC/TAZ dosage in the over-75-year-old patients, when they are administered PIPC/TAZ. Therefore, the findings of present study may contribute to improving the efficacy and safety of the administration of PIPC/TAZ therapy in late elderly patients with pneumonia.
| S-EPMC7148462 | biostudies-literature