Vancomycin AUC0-24 estimation using first-order pharmacokinetic methods in pediatric patients.

INTRODUCTION: The optimal dosing and monitoring of vancomycin in pediatrics is still unknown but has evolved to emphasize area under the curve over 24 h (AUC0-24) over minimum concentration (Cmin) monitoring. Real-world data supporting the feasibility of two-concentration kinetics with first-order equations for the estimation of vancomycin AUC0-24 in pediatric patients are lacking. OBJECTIVES: To describe the interplay of vancomycin dose, AUC0-24, and Cmin using first-order equations within four pediatric age groups. METHODS: This is a single-center, retrospective cohort study analyzing pediatric patients (<18 years) receiving intravenous vancomycin between 2020 and 2022. Included patients received at least 24 h of intravenous vancomycin with two concentrations obtained within 96 h of therapy initiation. Patients with baseline renal dysfunction were excluded. Patients were divided into four age categories: neonates (≤28 days), infants (29 days to <1 year), children (1-12 years), and adolescents (13-17 years). First-order equations were utilized to estimate pharmacokinetic parameters and AUC0-24. RESULTS: Overall, 219 patients (median age of 6 years [IQR 1-12]) met inclusion criteria. The median vancomycin daily dose was 30 mg/kg in neonates, 70 mg/kg in infants and children, and 52 mg/kg in adolescents. Median Cmin and AUC0-24 values among all age groups were 8.68 mg/L and 505 mg * h/L, respectively. For AUC0-24 values outside of the therapeutic range (400-600 mg * h/L), more values were SUPRAtherapeutic (>600 mg * h/L) than SUBtherapeutic (<400 mg * h/L). The overall trend within our data showed suboptimal correlation between Cmin and AUC0-24. However, 71% of patients with Cmin values of 5-10 mg/L had an AUC0-24 within the therapeutic range of 400-600 mg * h/L, whereas 23 patients (92%) with a SUPRAtherapeutic AUC0-24 had a Cmin value ≥15 mg/L. Approximately 10% of patients experienced acute kidney injury. CONCLUSIONS: Our data describe the relationship between vancomycin dose, Cmin, and AUC0-24 in pediatric patients. We demonstrated the feasibility of using first-order equations to estimate AUC0-24, using two concentrations obtained at steady state to monitor efficacy and safety in pediatric patients receiving intravenous vancomycin. Our data showed suboptimal correlation between AUC0-24 and Cmin, which indicates that Cmin should not be used as a surrogate marker for a therapeutic AUC0-24 in pediatric patients. In alignment with the 2020 vancomycin consensus guidelines, we suggest utilizing AUC0-24 for efficacy and safety monitoring.

A decade of change: The evolution of pharmacy services at U.S. cystic fibrosis centers.

INTRODUCTION: People with cystic fibrosis (pwCF) require a multidisciplinary care team due to disease complexity. The Cystic Fibrosis Foundation (CFF) notes that pharmacists are recommended, while other organizations consider pharmacists required. In 2016, the CFF initiated a grant program for CFF-accredited care centers and affiliate programs (CFF-ACCAP) to implement outpatient pharmacy services. The primary objective of this study was to compare surveys regarding pharmacy involvement in CFF-ACCAP pre- and post-grant implementation. METHODS: This was an IRB-approved, survey-based study. The surveys were distributed via the CF pharmacist-pharmacy technician and center director e-mail exchanges. RESULTS: There are currently 244 CFF-ACCAP and 158 pharmacists. Forty-two pharmacists completed the 2013 survey and 77 completed the 2023 survey. Practice site shifted from primarily the inpatient (58.5%) to outpatient settings (67.5%; p < .001). Most positions were created in the past 7 years (81%) with 50% currently or previously funded by the CFF grant program. CFF center director response decreased from 2013 to 2023 (106 vs. 48) but centers with a dedicated CF pharmacist increased from 2013 to 2023 (66%-86%; p = .014). In the 2023 survey, we received responses from 17 pharmacy technicians, who were newly included. Most of these technicians (64%) reported working in outpatient clinics. CONCLUSIONS: Since 2013, pharmacy presence has grown at CFF-ACCAP, partly due to the CFF grant program. Despite pharmacists not being required members of the multidisciplinary care team, their presence is notable in 65% of CFF-ACCAP centers, where they contribute significantly to improving the care provided for pwCF.

Assessment of long-term medication adherence with cystic fibrosis: An integrated approach.

INTRODUCTION: Cystic fibrosis (CF) is a genetic disorder that creates a multisystem pathology resulting in complex treatment regimens. In 2014, 43% of people with CF at an academic medical center experienced medication acquisition barriers. The creation of an integrated specialty pharmacy with an embedded CF team pharmacist was launched in 2016. In addition to filling specialty medications, this specialty pharmacy filled all patient medications through a service called total care pharmacy (TCP). This service was hypothesized to positively impact medication adherence. METHODS: Adherence analysis was performed by utilizing the proportion of days covered (PDC). PDC was analyzed during years 1, 2, and 3 of therapy. PDC was calculated for medications with at least three fills during each year. Patients with PDC less than 80% were considered nonadherent and underwent manual chart review to identify a documented reason for nonadherence. RESULTS: Patients in the first year of dornase alfa therapy had significantly higher adherence in the TCP cohort compared to non-TCP (81.3% PDC vs. 66.0%; p = .006), which was largely driven by adult patients (73.3% vs. 56.5% for pediatric). Analysis of other medications and groups did not yield statistically significant differences. Many patients who had been classified as nonadherent had valid clinical reasons that explained gaps in therapy. CONCLUSIONS: When filling medications at a specialty pharmacy integrated within the academic medication center, dornase alfa adherence was higher in the TCP group. Further studies comparing TCP with services offered by pharmacies external to the health system would better characterize the impact of TCP services.

Retrospective review of vancomycin monitoring via trough only versus two-point estimated area under the curve in pediatric and adult patients with cystic fibrosis.

OBJECTIVES: The primary objective of this study was to compare the occurrence of acute kidney injury (AKI) in patients with cystic fibrosis (CF) receiving intravenous (IV) vancomycin monitored through single serum trough concentrations and two-point estimated area under the curve (AUC). Time to next exacerbation and return to baseline lung function were also assessed. METHODS: A retrospective review was conducted in patients of all ages with CF admitted to the University of Kentucky who received IV vancomycin between October 2015 and January 2021. Patients were excluded if they received less than 5 days of IV vancomycin therapy. RESULTS: A total of 113 adults and 42 pediatric encounters met the inclusion criteria. There was no statistically significant difference in occurrence of AKI, however, all grade 2-3 AKIs were in the serum through the monitoring group. Adult patients monitored with AUC also had a higher return to baseline lung function over trough monitoring (86% vs. 57%) (p = 0.002). There was not a statistically significant difference in time to the next exacerbation in either group. CONCLUSIONS: Adult patients with CF experienced less severe AKIs when monitored with AUC versus trough. The results of this study indicate that AUC monitoring may enhance the efficacy of IV vancomycin in adult patients with CF.

The use of elexacaftor/tezacaftor/ivacaftor in patients with cystic fibrosis postliver transplant: A case series.

INTRODUCTION: Cystic fibrosis (CF)-related liver disease (CFLD) manifests as a wide spectrum of hepatobiliary disease and can progress to need liver transplantation. Elexacaftor/tezacaftor/ivacaftor (elx/tez/iva) is a cystic fibrosis transmembrane conductance regulator modulator that has superior efficacy compared to previously approved modulators. Use of elx/tez/iva, should be approached with caution in individuals with CFLD or following liver transplantation due to possible increases in liver function tests (LFTs) and drug-drug interactions with several immunosuppressant medications. OBJECTIVE: The purpose of this case series is to explore if the use of elx/tez/iva is safe and tolerable in patients with CF postliver transplantation. METHODS: A retrospective case series including patients prescribed elx/tez/iva following liver transplantation and an immunosuppressive regimen consisting of drug therapy metabolized by P-glycoprotein was completed. RESULTS: Ten patients at six CF centers with a median age of 22.1 years (range 14-43.4 years) and the median time from the transplant of 6.9 years (range 0.6-22 years) were included. Most patients (8, 80%) received a reduced or full dose of elx/tez/iva for a mean duration of 10.4 months (range 7-12 months). Fluctuations in LFTs occurred in all patients (10, 100%) and led to therapy discontinuation in two patients (20%). Elx/tez/iva initiation resulted in elevations in tacrolimus trough concentration in seven patients (70%). Most patients who tolerated elx/tez/iva had symptomatic and quality of life improvement, increased body mass index, and maintained or improved lung function. CONCLUSION: Initiation of elx/tez/iva in patients with CF who received liver transplantation may be safe with clinical benefits.

Optimization of Vancomycin Dosing to Achieve Target Area Under the Curve in Pediatrics.

OBJECTIVE: Vancomycin dosing requirements to achieve a target area under curve/minimum inhibitory concentration (AUC/MIC) of 400 to 600 mg•hr/L have not been established in pediatrics. Dose modeling studies and recent guidelines suggest dosing higher than historical recommendations. This study examines dosing requirements to achieve target AUC/MIC in human pediatric patients. METHODS: This retrospective study includes 77 patients, aged 1 month to 18 years, at a single center, who received at least 2 days of intravenous vancomycin with a pharmacokinetic monitoring note and calculated AUC/MIC. Dosing to achieve target AUC/MIC was evaluated by age and indication. Nephrotoxicity was also assessed. RESULTS: The mean dose required to achieve target AUC/MIC for all patients was 67.7 mg/kg/day. Adjusting for age, the mean dose required to achieve target AUC/MIC of 400 to 600 mg•hr/L was found to be statistically significantly different among 3 age cohorts: 1 month to 5 years, 6 to 12 years, and 13 to 18 years [F(2,74) = 15.32, p < 0.001], with mean requirements of 79 ± 14.1, 65.6 ± 21.1, and 53.9 ± 17.1 mg/kg/day, respectively. Dosing requirements were also found to be statistically significantly different across indications [F(6,70) = 4.84, p < 0.001]. Acute kidney injury was identified in 5 patients (6.5%). CONCLUSIONS: The vancomycin dose required to achieve target AUC/MIC in pediatrics was significantly higher in younger pediatric patients and ranged from 53.9 to 79 mg/kg/day, confirming recent guideline recommendations. Doses can be further adjusted for indication. Nephrotoxicity rates remain low compared with historical rates with single trough monitoring.

The Role of Biologics in the Management of Asthma in the Pediatric Patient.

The management of pediatric patients with asthma continues to be a major health issue. For many patients, traditional therapies have been very effective, but for a large number of patients asthma remains poorly controlled. This leads to significant morbidity and impairment to quality of life. Recently, several new biologics, as well as new dosage forms of combination inhaled drugs, have been made available for use adding to the armamentarium of therapy for specific asthma phenotypes. Biologics have shown promise in the more difficult to manage asthma patient. Approved in children, omalizumab, an anti-immunoglobulin E (anti-IgE) antibody, has been available for several years. New agents, like mepolizumab and benralizumab, directed against interleukin (IL) 5, have indications for children >6 and >12 years of age, respectively. Dupilumab, an IL-4- and IL-13-directed antibody, has been studied as well in eosinophilic asthma, with positive results. A thorough understanding of the clinical data of these agents is key, as they may greatly improve the quality of life in children with difficult-to-manage asthma.

Comparison of the predictive value of area under the curve versus maximum serum concentration of intravenous tobramycin in cystic fibrosis patients treated for an acute pulmonary exacerbation.

OBJECTIVES: The primary objective of this study was to compare the therapeutic predictive value of area under the curve (AUC24 ) versus maximum concentration (Cmax ) in cystic fibrosis (CF) patients receiving intravenous (IV) tobramycin for a Pseudomonas aeruginosa (PsA) acute pulmonary exacerbation (APE). Acute kidney injury (AKI) incidence and the relationship between time undetectable and efficacy were also assessed. METHODS: A retrospective review was conducted in patients aged at least 1 month with a diagnosis of CF receiving IV tobramycin for treatment of a PsA APE and admitted to the University of Kentucky between August 2015 and August 2019. Patients were excluded if they had no growth of PsA on sputum culture or if two postdose tobramycin levels were not obtained following a dose adjustment of ≥20%. RESULTS: A total of 44 pediatric and 107 adult patient encounters met inclusion criteria. In patients with therapeutic success (n = 91), 75.8% had an AUC24 ≥80% and 80.3% had a Cmax ≥8 times the highest PsA minimal inhibitory concentration. There was a significant correlation between AUC24 and Cmax (r[149] = 0.727; p < 0.001). AKI incidence was significantly higher in patients receiving IV tobramycin dosed multiple times daily versus at least every 24 h (χ2 [1, 151] = 3.9; p = 0.047). CONCLUSIONS: The results of this study indicate that both AUC24 and Cmax serve as relatively accurate predictors of tobramycin efficacy. Additionally, given the significant increase in incidence of AKI, multidaily dosing of IV tobramycin should be avoided in pediatric and adult patients with CF.

CFTR modulator drug desensitization: Preserving the hope of long term improvement.

The development of modulator therapy has, for the first time, allowed direct targeting of the underlying cause of cystic fibrosis (CF), the cystic fibrosis transmembrane conductance regulator (CFTR). Patients treated with CFTR modulators have improvement in lung function and decreased rates of pulmonary exacerbations. In 2019, elexacaftor/tezacaftor/ivacaftor was approved for use in the United States, opening these therapies to 90% of patients with CF. Intolerable adverse drug reactions to CFTR modulators results in discontinuation of therapy, which can be devastating to our patients. We describe our approach to two cases, not previously reported, of rash to elexacaftor/tezacaftor/ivacaftor in patients with a previous history of cutaneous adverse reactions to dual modulator therapy that had been addressed by desensitization. Case 1 was able to tolerate elexacaftor/tezacaftor/ivacaftor after desensitization to the triple combination therapy, while in Case 2 tolerance was obtained by treating through the reaction. The loss of tolerance in these patients was unexpected, and may be a common finding in patients with history of cutaneous adverse reactions to these drugs. We hope reporting our experience, including our desensitization protocol, may benefit CF patients for whom these drug reactions may be limiting access to powerful disease altering therapies.

Levetiracetam Compared to Phenobarbital as a First Line Therapy for Neonatal Seizures: An Unexpected Influence of Benzodiazepines on Seizure Response.

OBJECTIVES: Neonatal seizures are common complications. Phenobarbital is the agent of choice but leads to adverse neurologic outcomes. There has been increased use of newer agents like levetiracetam. The objective of this study was determining the rate of seizure resolution in neonates treated with phenobarbital or levetiracetam. METHODS: This was a retrospective, single-center, cohort study from June 1, 2012-June 1, 2018 evaluating seizure resolution in neonates following first-line treatment with phenobarbital versus levetiracetam. Data were collected via review of the patient's charts in the electronic medical record. The primary outcome was seizure resolution without addition of a second antiepileptic agent. Logistic regression was used to assess the impact of pertinent variables. RESULTS: Each group included 73 patients. The mean gestational age was 36.01 and 37.91 weeks for the phenobarbital and levetiracetam groups, respectively (p = 0.011). The phenobarbital group had higher rates of intraventricular hemorrhage at baseline. The median birth weight was 2750 and 3002 grams in the phenobarbital and levetiracetam groups, respectively (p = 0.10). Forty-five neonates (61.6%) achieved seizure resolution with phenobarbital compared with 30 neonates (41.1%) with levetiracetam (p = 0.01). In neonates who did not receive a benzodiazepine, seizure resolution was similar between groups (51-52%). In neonates who received a benzodiazepine, seizure resolution rate was 94.1% (16/17 neonates) for phenobarbital and 18.2% (4/22 neonates) for levetiracetam. CONCLUSIONS: These findings suggest seizure resolution with levetiracetam, and phenobarbital may be impacted by benzodiazepine administration. If no benzodiazepine is used, these agents demonstrated similar efficacy. Further research into the pharmacodynamic interaction with benzodiazepines is necessary.

Pharmacist Survey: Pharmacist Perception of Vancomycin Area Under the Curve Therapeutic Drug Monitoring.

BACKGROUND: Evidence suggests the standard vancomycin trough goal of 15 to 20 mg/L for serious Staphylococcus aureus infections is associated with acute kidney injury, whereas appropriate monitoring of 24-hour area under the curve (AUC) may decrease nephrotoxicity. As a result, institutions have transitioned to AUC monitoring, the predictive pharmacokinetic/pharmacodynamic parameter of vancomycin to improve safety outcomes. However, this method may require increased pharmacist time and effort. Pharmacist perception of the practice change is largely unknown and warrants investigation. METHODS: An electronic survey was disseminated via e-mail to pharmacists 5 months post-AUC implementation. Items of interest were focused on pharmacist perception, including quantity of patients monitored using AUC, justification of the practice change, differences in efficacy and safety, and changes in monitoring time requirements. RESULTS: The pharmacist survey was distributed to 196 pharmacists and 84 responded (43% response rate). Eighty-one pharmacists had monitored patients using AUC methods. Sixty-nine percent of these respondents perceived the change to result in increased or slightly increased patient safety, 27% described no difference, and 4% stated safety was decreased or slightly decreased. Forty-two percent perceived the transition to result in increased or slightly increased efficacy, while 48% noted no difference and 10% responded that efficacy was decreased or slightly decreased. Pharmacists stated the creation of an institutional calculator decreased the time required to calculate AUC. CONCLUSION: After the change to AUC monitoring, pharmacists perceived improvements in safety outcomes while efficacy was at least similar if not increased.

Evaluation of Two Fosphenytoin Loading Dose Regimens and Monitoring in Infants and Neonates Less Than Six Months of Age.

OBJECTIVES: The objectives of the study were to compare the free serum concentrations after different fosphenytoin loading dose strategies in patients younger than 6 months old and to investigate the frequency of seizure cessation following a loading dose of fosphenytoin. METHODS: This retrospective cohort study included neonates and infants admitted to a 150-bed children's hospital between August 1, 2014, and February 1, 2018. Patients were included if they were younger than 6 months old and had a postload free phenytoin serum concentration collected during the specified time frame. Patients were identified through a database query screening for the inclusion criteria. Patients were separated into 2 groups with the 15 mg/kg group as per protocol and the 20 mg/kg group as noted in common practice. Data collection included demographic information, fosphenytoin dose, time of administration of the fosphenytoin loading dose, time of sampling, free phenytoin serum concentration results, concomitant antiepileptic agents, albumin serum concentration, and total bilirubin serum concentration. RESULTS: Forty-one patients were included for analysis, 12 in the 15 mg/kg group and 29 in the 20 mg/kg group. The average free phenytoin concentration after the loading dose was 2.45 ± 0.54 mg/L in the 15 mg/kg group and 2.52 ± 0.66 mg/L in the 20 mg/kg group. Seizure cessation after the fosphenytoin loading dose was achieved in 3 of 12 (25%) patients in the 15 mg/kg group and in 13 of 29 (45%) patients in the 20 mg/kg group (p = 0.305). CONCLUSIONS: The study demonstrates that a traditional range of fosphenytoin loading dose (15-20 mg/kg) led to elevated postloading dose free phenytoin serum concentrations in the majority of patients with a seizure cessation rate of approximately 39%. The question remains as to what the optimal dose and target concentration should be in this patient population to achieve the best efficacy without risking associated toxicities.

Incidence of nephrotoxicity with prolonged aminoglycoside exposure in patients with cystic fibrosis.

Cystic fibrosis (CF) patients, with Pseudomonas aeruginosa infection, often require repeated aminoglycoside courses for the management of acute pulmonary exacerbations (APEs). Acute kidney injury (AKI) due to aminoglycosides has been reported; little data exist regarding long-term nephrotoxicity with repeated exposure. The objective of this study was to describe the incidence of acute and chronic nephrotoxicity due to cumulative intravenous (IV) aminoglycoside exposure. This is a retrospective, observational study of pediatric and adult CF patients admitted to an academic medical center between January 1, 2006 and October 1, 2018 for APE management. Patients were eligible for inclusion if they received at least five courses of an IV aminoglycoside for at least 7 days each. Cumulative weight-based aminoglycoside dose was reported in milligrams per kilogram. For each admission, baseline and highest serum creatinine were collected to assess the incidence of AKI. The baseline and final estimated glomerular filtration rate (eGFR) were calculated to assess long-term effects on renal function. Sixty-six patients, representing greater than 700 courses, were included in the final analysis. The median cumulative weight-based aminoglycoside dose was 1183 mg/kg of tobramycin or tobramycin equivalent. Twenty percent of courses resulted in AKI; 86% were Stage 1. A repeated measure multivariate model showed colistin, piperacillin/tazobactam, vancomycin, and age were significant AKI risk factors. There was no correlation between cumulative aminoglycoside dose and change in eGFR. AKI from IV aminoglycoside exposure occurred in 20% of courses. Cumulative exposure to IV aminoglycosides in APE management was not correlated with long-term renal dysfunction.

Vancomycin Area Under the Curve Dosing and Monitoring at an Academic Medical Center: Transition Strategies and Lessons Learned.

Due to the inconsistent correlation of vancomycin trough concentrations with 24-hour area under the curve (AUC) and a desire to reduce rates of vancomycin-associated acute kidney injury, an institutional guideline was implemented by the Antimicrobial Stewardship Team in September 2017 to monitor vancomycin using AUC. Three stages were utilized to organize the process: preparation, implementation, and evaluation. The preparation stage was used to present literature to key stakeholders, and pharmacy meetings focused on the development of a dosing and monitoring guideline. Along with institution-wide education, the implementation stage included information technology development and support. The evaluation stage was comprised of quality improvement and clinical research. Future plans include dissemination of the results and analyses. Numerous lessons were learned due to barriers experienced during the process, but the transition was successful.

Outcomes of Lung Transplantation for Cystic Fibrosis in the Setting of Extensively Drug-Resistant Organisms.

INTRODUCTION: Since the largest study on extensively drug-resistant organisms and lung transplantation in patients with cystic fibrosis, there have been innovations and advancements in the treatment of Pseudomonas aeruginosa. RESEARCH QUESTION: What differences exist for patients with cystic fibrosis with a history of extensively drug-resistant infections who undergo lung transplantation despite treatment advances with antimicrobial therapy? STUDY DESIGN: Two-center, retrospective, cohort study conducted in 44 patients with cystic fibrosis chronically infected with extensively drug-resistant organisms who received a lung transplant from January 2008 through August 2016. Patients in the resistant cohort were chronically infected with pan-resistant P aeruginosa, polymyxin-sensitive only, or sensitive to 2 antibiotic classes (polymyxin plus one other); remaining patients with more susceptible P aeruginosa or no P aeruginosa remained in the control cohort. The primary outcome is a composite of patient survival, retransplantation, chronic lung allograft dysfunction, and acute rejection 12 months posttransplant. Categorical variables were analyzed using χ2 testing. The independent samples t test was utilized for continuous variables. RESULTS: There was no difference in the primary outcome (40% vs 37%, P = .831). Differences between patient survival (84% vs 95%, P = .487), the incidence of acute rejection (20% vs 33%, P = .323), and the incidence of chronic lung allograft rejection (12% vs 5%, P = .441) were not different between groups. DISCUSSION: Recipients chronically infected with an extensively resistant P aeruginosa had similar outcomes compared to those infected with more sensitive organisms.

Patients and families experience with pharmacist care at cystic fibrosis foundation accredited clinics.

Cystic fibrosis (CF) is a complex genetic, multiorgan disease. The CF Foundation (CFF) recommends a multidisciplinary team (physician, nurse, respiratory therapist, dietitian, physical therapist, social worker, mental health coordinator, clinic coordinator, and pharmacist) to work with patients and families. The objective of our study was to describe the impact of a pharmacist involved in the care of patients and families from their perspective. The CF Patient and Family Experience of Care (PFEC) is a voluntary, 50-question telephonic or internet-based survey designed to continuously collect information from patients and their families regarding their care experience. From August of 2017 through February of 2018, five questions were added to the internet survey to assess the impact of the pharmacist on the care experience. From the 666 respondents, 54% reported that a pharmacist was involved in their CF care. At two CF clinics designated as "full access" to a pharmacist, respondents reported a higher percentage of the CF-team discussed medications compared to those from three clinics designated as "limited access" to the pharmacist (95% vs 67%). Respondents in clinics with "full access" to a pharmacist were significantly more likely to get their medications refilled on time (78% vs 63%) and reported using fewer pharmacies to fill their medications. Pharmacist involvement in CF care may improve patient's access to medication and the ability to sustain use.

Survey of the Current Use of Dexmedetomidine and Management of Withdrawal Symptoms in Critically Ill Children.

OBJECTIVES: Dexmedetomidine use for sedation in the pediatric intensive care units (PICUs) has increased since its initial US Food and Drug Administration (FDA) approval in adults. However, there is limited evidence to direct providers regarding current usage, dosing, and monitoring for withdrawal symptoms in pediatric patients. This study sought to determine the utilization of dexmedetomidine and management of dexmedetomidine withdrawal symptoms among PICU physicians. METHODS: A questionnaire survey was distributed to all members of the American Academy of Pediatrics Section on Critical Care. It assessed the practice site demographics, indication, dosing, and duration of dexmedetomidine infusion, unit protocol, and strategies for management of dexmedetomidine withdrawal. RESULTS: A total of 147 surveys (21.1%) were returned and analyzed. The reported uses for dexmedetomidine were as a primary sedative (59.9%), adjunctive agent for sedation (82.3%), and adjunctive agent to assist weaning sedation (62.6%) or from mechanical ventilation (70.1%). One hundred twenty-nine respondents (87.8%) had concerns over dexmedetomidine withdrawal, with 59 respondents becoming concerned after 120 hours of infusion (45.7%). Most respondents reported managing dexmedetomidine withdrawal symptoms via a regimented wean and initiation of clonidine (81%). Units with >1000 admissions per year were more likely to have a protocol related to dexmedetomidine use (p = 0.021). Units with >1000 admissions per year reported using clonidine for withdrawal at a higher rate, whereas units with ≤1000 admissions per year used a systematic wean of dexmedetomidine (p = 0.014). CONCLUSIONS: Dexmedetomidine use in the PICU is varied among pediatric intensive care physicians. Intensivists have withdrawal concerns after dexmedetomidine discontinuation, and the primary management of this withdrawal phenomenon is the initiation of clonidine with a regimented dexmedetomidine wean.

Amikacin target achievement in adult cystic fibrosis patients utilizing Monte Carlo simulation.

AIM: Pseudomonas aeruginosa (PsA) is a common pathogen in cystic fibrosis (CF). Management of an acute pulmonary exacerbation (APE) caused by PsA is dual anti-pseudomonal antibiotics, a beta-lactam plus aminoglycoside. Aminoglycoside dosing in CF differs from the general population due to altered pharmacokinetics. The primary objective of this study was to utilize pharmacokinetic data from adult CF patients that received amikacin to determine the probability of target attainment for APEs caused by PsA. METHODS: This was a single-center, non-randomized, retrospective cohort study of patients >18 years with CF that received intravenous amikacin between January 2010 and July 2016. Amikacin dose, frequency, and serum concentrations were used to calculate pharmacokinetic parameters assuming a one-compartment model. Monte Carlo simulation was conducted with MIC values from CF patients with a PsA positive sputum culture between January 2014 and September 2016 to predict concentration-time profiles for different doses of amikacin. RESULTS: This study included pharmacokinetic parameters for 14 amikacin courses administered to six unique patients. The average empiric dose of amikacin was 24.3 ± 14.6 mg/kg, achieving a peak:MIC ratio ≥8 at a rate of 37% (median 5.87; IQR 3.05-10.96). A dose of 45 mg/kg/day was needed to achieve target peak:MIC ratios 90% of the time for a PsA MIC of 8 mg/L. CONCLUSION: Our data suggests it may not be clinically feasible to utilize amikacin for PsA isolates with a MIC of 16 mg/L. Current guideline dosing recommendations of amikacin 30-35 mg/kg/day are only adequate for PsA with a MIC ≤4 mg/L.