Superiority of ceftazidime off-label high-dose regimen in PK/PD target attainment during treatment of extensively drug-resistant Pseudomonas aeruginosa infections in cancer patients.

AIM: The objective of this study was to evaluate off-label high-dose ceftazidime population pharmacokinetics in cancer patients with suspected or proven extensively drug-resistant (XDR) Pseudomonas aeruginosa infections and then to compare the achievement of the pharmacokinetic/pharmacodynamic (PK/PD) target after standard and off-label high-dose regimens using population model-based simulations. A further aim was to clinically observe the occurrence of adverse effects during the off-label high-dose ceftazidime treatment. METHODS: In patients treated with off-label high-dose ceftazidime (3 g every 6 h), blood samples were collected and ceftazidime serum levels measured using LC-MS/MS. A pharmacokinetic population model was developed using a nonlinear mixed-effects modelling approach and Monte Carlo simulations were then used to compare standard and high-dose regimens for PK/PD target attainment. RESULTS: A total of 14 cancer patients with serious infection suspected of XDR P. aeruginosa aetiology were eligible for PK analysis. XDR P. aeruginosa was confirmed in 10 patients as the causative pathogen. Population ceftazidime volume of distribution was 13.23 L, while clearance started at the baseline of 1.48 L/h and increased by 0.0076 L/h with each 1 mL/min/1.73 m2 of eGFR. High-dose regimen showed significantly higher probability of target attainment (i.e., 86% vs. 56% at MIC of 32 mg/L). This was translated into a very low mortality rate of 20%. Only one case of reversible neurological impairment was observed. CONCLUSION: We proved the superiority of the ceftazidime off-label high-dose regimen in PK/PD target attainment with very low occurrence of adverse effects. The off-label high-dose regimen should be used to optimize treatment of XDR P. aeruginosa infections.

Recombinant human thrombopoietin (rhTPO) of different dosing regimens for refractory/relapsed primary immune thrombocytopenia: a multicenter, randomized controlled trial and pharmacokinetics study.

Recombinant human TPO (rhTPO) is effective for refractory/relapsed primary immune thrombocytopenia (ITP), but optimal dosing regimen remains elusive. In this multicenter, randomized, controlled trial, a total of 282 adult ITP patients (mean age 47.3 years; 82 men) with a platelet count ≤30 × 109/L or >30 × 109/L with active bleeding randomly received a once daily (QD) subcutaneous injection of 7500 U (n = 64) or 15000 U rhTPO for 14 injections, or 15000 U or 30000 U rhTPO once every other day (QOD) for 7 injections. The primary outcomes included change from baseline in platelet count and total response rate (TRR) on day 14. On day 14, the median increase of platelet count from baseline was the highest in the 15000-U QD group (167.5 × 109/L, interquartile range [IQR] 23.0-295.0 × 109/L), followed by the 30000-U QOD group (57.5 × 109/L, IQR 9.0-190.0 × 109/L) (ANCOVA P < .001; P = .266 with baseline count as a covariate). The TRR on day 14 was also the highest in the 15000-U QD group (63.2%), followed by the 30000-U QOD group (59.7%). The rate of grade 3 and above adverse events did not differ among the four groups. There were no new safety concerns. All 4 regimens are safe and well-tolerated. The 30000-U QOD regimen is practically indistinguishable in efficacy to the 15000-U QD regimen.

What is the context? Relative thrombopoietin deficiency is implicated in primary immune thrombocytopenia (ITP), which is characterized by increased platelet destruction and impaired megakaryopoiesis.Patients who are innately unresponsive to or have relapsed after glucocorticoid treatment have limited treatment options.Recombinant human thrombopoietin (rhTPO) improves treatment response of primary ITP patients when added to high-dose dexamethasone.What is new? This trial sought to identify an optimal dosing regimen of rhTPO for patients who had failed or relapsed after glucocorticoid therapy.Of the 4 regimens, once daily 15000 U rhTPO for 14 injections yielded the greatest median increase in platelet count (167.5 × 10⁹/L) from baseline and attained the highest total response rate on day 14 (63.2%).30000 U rhTPO once every other day for 7 injections was effective in rapidly increasing platelet counts in the first 7 days.All 4 regimens were safe and well-tolerated.What is the impact? The 30000 U rhTPO once every other day regimen may offer an effective and safe regimen with less frequent injections, but future trials with longer follow-up are needed.

Pharmacokinetics of intravenous daptomycin in Japanese pediatric patients: Pharmacokinetic comparisons supporting dosing recommendations in Japanese pediatric patients.

INTRODUCTION: The pharmacokinetics (PK) of daptomycin has not been previously characterized in Japanese pediatric patients with complicated skin and soft tissue infections (cSSTI) or bacteremia. An aim of the study includes evaluation of PK of daptomycin in Japanese pediatric patients and an appropriateness of the age-specific, weight-based dosing regimens in Japanese pediatric patients based on PK comparison with Japanese adult patients. METHODS: The phase 2 trial enrolled Japanese pediatric patients (age 1-17 years) with cSSTI (n = 14) or bacteremia (n = 4) caused by gram-positive cocci in order to evaluate safety, efficacy and PK. The Phase 3 trial in Japanese adult patients (SSTI n = 65, septicemia/right-sided infective endocarditis (RIE) n = 7) was referred to for PK comparison between adult and pediatric. Daptomycin concentrations in plasma were analyzed by reverse-phase high-performance liquid chromatography (HPLC). PK parameters were determined using non-compartmental analysis in Japanese pediatric and Japanese adult patients. The exposures in Japanese pediatric patients were graphically compared with those in Japanese adult patients. The relationship between daptomycin exposures and creatine phosphokinase (CPK) elevation was explored visually. RESULTS: Following administration of the age-specific, weight-based dosing regimens, daptomycin exposures were overlapping across age groups in pediatric patients with cSSTI with similar observations based on clearance. The distribution of individual exposure in Japanese pediatric patients was overlapping with that in Japanese adult patients. No apparent relationship between daptomycin exposures and CPK elevation in Japanese pediatric patients was observed. CONCLUSIONS: The results suggested that the age-specific, weight-based dosing regimens are considered to be appropriate in Japanese pediatric patients.

Population pharmacokinetic model and dosing optimization of vancomycin in hematologic malignancies with neutropenia and augmented renal clearance.

AIM: Data on the pharmacokinetics (PK) and area under the curve (AUC)-based dosing strategy of vancomycin (VCM) in hematologic malignancies are limited. According to our preliminary narrative review, only a few population PK analyses in hematologic malignancies have been performed. Therefore, we aimed to develop a population PK model, investigate the factors influencing VCM PK, and propose an optimal dosing regimen for hematologic malignancies. METHODS: A retrospective study was conducted in patients with underlying hematologic malignancies treated with VCM. A total of 148 patients were enrolled for population PK modeling. Simulation analyses were performed to identify dosing regimens achieving a target exposure of AUC0-24 of 400-600 mg h/L at the steady-state. RESULTS: The VCM PK data were best described with a one-compartment model. Significant covariates included creatinine clearance (Ccr), diagnosis of acute myeloid leukemia (AML) and neutropenia on VCM clearance (CL), and body weight (WT) on the volume of distribution (Vd). The typical values of CL and Vd were 3.09 L/h (normalized to Ccr value of 90 mL/min) and 122 L/70 kg, respectively. Concerning the effect on VCM dosing, AML patients required 15% higher doses than non-AML patients, independently of renal function. In contrast, for neutropenic patients, only those with augmented renal clearance (ARC, Ccr value ≥ 130 mL/min) required a 10% dose increase compared to non-neutropenic patients. CONCLUSION: AML patients with neutropenia and ARC represent a critical population with a higher risk of VCM underexposure. Thus, individualized dosing adjustment and therapeutic drug monitoring are strongly recommended.

Effectiveness of three Vitamin D dosing protocols on raising and maintaining blood serum levels of 25-hydroxyvitamin D over a three-month period: a randomized, prospective study.

INTRODUCTION: Vitamin D has gained attention in the medical community due to its critical role in calcium homeostasis and overall bone health. No standard vitamin D dosing protocol in fracture care has been established for patients deficient in 25-hydroxyvitamin D. This prospective and randomized study aimed to find a dosing regimen that would safely achieve and maintain a therapeutic level of 25-hydroxyvitamin D in deficient patients over three months. MATERIALS AND METHODS: Between June 2016 and May 2017, 48 patients with baseline total 25-hydroxyvitamin D less than 30.0 ng/mL were randomly assigned to either group one (one dose of 100,000 international units (IU) of Vitamin D2) or group 2 (100,000 IU of Vitamin D2 once weekly for twelve weeks) or group 3 (50,000 IU of Vitamin D2 daily for ten days followed by 2,000 IU of Vitamin D3 daily for 74 days). Baseline serum levels were drawn followed by interval levels at week 2, 6 and 12. The primary outcome was to determine which protocol could achieve and maintain therapeutic levels of total 25-hydroxyvitamin D over the course of three months. Our secondary outcome was to monitor for negative side effects. RESULTS: Group 1 did not show any statistically significant increase in serum levels and had no reported side effects. There was a statistically significant increase in serum total 25-hydroxyvitamin D in group 2 between all-time points except between weeks 6 and 12. Two (12.5%) participants in group 2 reported side effects. Group 3 had the greatest change in serum levels from weeks 0 to 2 but had a significant decrease between weeks 2 and 6. No change was seen between weeks 6 and 12. Three (17.5%) participants in group 3 reported side effects. CONCLUSIONS: Group 2 sustained and maintained a satisfactory level of total 25-hydroxyvitamin D over three months without any severe side effects.

Patient-centered dupilumab dosing regimen leads to successful dose reduction in persistently controlled atopic dermatitis.

BACKGROUND: At present, no real-world studies are available on different dupilumab dosing regimens in controlled atopic dermatitis (AD). The aim of this study was to clinically evaluate a patient-centered dupilumab dosing regimen in patients with controlled AD and to relate this to serum drug levels and serum biomarkers. METHODS: Ninety adult AD patients from the prospective BioDay registry were included based on their dupilumab administration interval according to a predefined patient-centered dosing regimen. Group A (n = 30) did not fulfill the criteria for interval prolongation and continued using the standard dupilumab dosage (300 mg/2 weeks), group B (n = 30) prolonged dupilumab interval with 50% (300 mg/4 weeks), and group C (n = 30) prolonged dupilumab interval with 66%-75% (300 mg/6-8 weeks). AD severity score, patient-reported outcomes, serum dupilumab levels, and serum biomarkers were analyzed over time. RESULTS: Disease severity scores did not significantly change over time during the tapering period in any of the groups. In groups B and C, the Numeric Rating Scale (NRS)-pruritus temporarily significantly increased after interval prolongation but remained low (median NRS-pruritus≤4). Median dupilumab levels remained stable in group A (standard dosage), but significantly decreased in groups B and C (24.1 mg/L (IQR = 17.1-45.6); 12.5 mg/L (IQR = 1.7-22.3)) compared with the levels during the standard dosage (88.2 mg/L [IQR = 67.1-123.0, p < .001]). Disease severity biomarker levels (CCL17/CCL18) remained low in all study groups during the whole observation period. CONCLUSIONS: This study showed that dose reduction was successful in a subgroup of patients with controlled AD by using a patient-centered dosing regimen. These patients showed stable low disease activity and low severity biomarkers over time.

A machine learning model that emulates experts' decision making in vancomycin initial dose planning.

Vancomycin is a glycopeptide antibiotic that is a primary treatment for methicillin-resistant Staphylococcus aureus infections. To enhance its clinical effectiveness and prevent nephrotoxicity, therapeutic drug monitoring (TDM) of trough concentrations is recommended. Initial vancomycin dosing regimens are determined based on patient characteristics such as age, body weight, and renal function, and dosing strategies to achieve therapeutic concentration windows at initial TDM have been extensively studied. Although numerous dosing nomograms for specific populations have been developed, no comprehensive strategy exists for individually tailoring initial dosing regimens; therefore, decision making regarding initial dosing largely depends on each clinician's experience and expertise. In this study, we applied a machine-learning (ML) approach to integrate clinician knowledge into a predictive model for initial vancomycin dosing. A dataset of vancomycin initial dose plans defined by pharmacists experienced in vancomycin TDM (i.e., experts) was used to build the ML model. Although small training sets were used, we established a predictive model with a target attainment rate comparable to those of experts, another ML model, and commonly used vancomycin dosing software. Our strategy will help develop an expert-like predictive model that aids in decision making for initial vancomycin dosing, particularly in settings where dose planning consultations are unavailable.

Linezolid Population Pharmacokinetics in South African Adults with Drug-Resistant Tuberculosis.

Linezolid is widely used for drug-resistant tuberculosis (DR-TB) but has a narrow therapeutic index. To inform dose optimization, we aimed to characterize the population pharmacokinetics of linezolid in South African participants with DR-TB and explore the effect of covariates, including HIV coinfection, on drug exposure. Data were obtained from pharmacokinetic substudies in a randomized controlled trial and an observational cohort study, both of which enrolled adults with drug-resistant pulmonary tuberculosis. Participants underwent intensive and sparse plasma sampling. We analyzed linezolid concentration data using nonlinear mixed-effects modeling and performed simulations to estimate attainment of putative efficacy and toxicity targets. A total of 124 participants provided 444 plasma samples; 116 were on the standard daily dose of 600 mg, while 19 had dose reduction to 300 mg due to adverse events. Sixty-one participants were female, 71 were HIV-positive, and their median weight was 56 kg (interquartile range [IQR], 50 to 63). In the final model, typical values for clearance and central volume were 3.57 liters/h and 40.2 liters, respectively. HIV coinfection had no significant effect on linezolid exposure. Simulations showed that 600-mg dosing achieved the efficacy target (area under the concentration-time curve for the free, unbound fraction of the drug [[Formula: see text] at a MIC level of 0.5 mg/liter) with 96% probability but had 56% probability of exceeding safety target ([Formula: see text]. The 300-mg dose did not achieve adequate efficacy exposures. Our model characterized population pharmacokinetics of linezolid in South African patients with DR-TB and supports the 600-mg daily dose with safety monitoring.

Over a decade of experience with carboplatin therapeutic drug monitoring in a childhood cancer setting in the United Kingdom.

The widely used platinum agent carboplatin represents a good example of an anticancer drug where clear relationships between pharmacological exposure and clinical response and toxicity have previously been shown. Within the setting of childhood cancer, there are defined groups of patients who present a particular challenge when dosing with carboplatin, including neonates and infants, those who are anephric, and poor prognosis patients receiving high-dose chemotherapy. For these groups, nonstandard chemotherapy dosing regimens are currently utilised, often with different approaches between clinical study protocols and between treatment centres. For the treatment of these patient populations in the UK, there is now significant experience in carrying out therapeutic drug monitoring, aiming to consistently achieve target drug exposures, maximise drug efficacy and minimise treatment-related side effects. An ongoing clinical trial is currently providing information on drug exposure for a wide range of anticancer agents in these hard to treat patient populations. In addition to supporting dosing decisions for individual patients, the collection and analysis of these data may allow the development of future dosing regimens. For example, current reduced dosing approaches for neonates and infants based on age or body weight, may well be better replaced by regimens based on a sound pharmacological rationale. The successful use of adaptive carboplatin dosing in childhood cancer should encourage the development of therapeutic drug monitoring approaches more widely in an oncology setting.

Population pharmacokinetics, safety and dosing optimization of voriconazole in patients with liver dysfunction: A prospective observational study.

AIMS: Voriconazole is a broad-spectrum antifungal agent for the treatment of invasive fungal infections. There is limited information about the pharmacokinetics and appropriate dosage of voriconazole in patients with liver dysfunction. This study aimed to explore the relationship between voriconazole trough concentration (Ctrough ) and toxicity, identify the factors significantly associated with voriconazole pharmacokinetic parameters and propose an optimised voriconazole dosing regimen for patients with liver dysfunction. METHODS: The study prospectively enrolled 51 patients with 272 voriconazole concentrations. Receiver operating characteristic curves were used to explore the relationship between voriconazole Ctrough and toxicity. The pharmacokinetic data was analysed with nonlinear mixed-effects method. Dosing simulations stratified by total bilirubin (TBIL, TBIL-1: TBIL < 51 µmol/L; TBIL-2: 51 µmol/L ≤ TBIL < 171 µmol/L; TBIL-3: TBIL ≥ 171 µmol/L) were performed. RESULTS: Receiver operating characteristic curve analysis revealed that voriconazole Ctrough of ≤ 5.1 mg/L were associated with significantly lower the incidence of adverse events. A 1-compartment pharmacokinetic model with first-order absorption and elimination was used to describe the data. Population pharmacokinetic parameters of clearance, volume of distribution and oral bioavailability were 0.88 L/h, 148.8 L and 88.4%, respectively. Voriconazole clearance was significantly associated with TBIL and platelet count. The volume of distribution increased with body weight. Patients with TBIL-1 could be treated with a loading dose of 400 mg every 12 hours (q12h) for first day, followed by a maintenance dose of 100 mg q12h administered orally or intravenously. TBIL-2 and TBIL-3 patients could be treated with a loading dose of 200 mg q12h and maintenance doses of 50 mg q12h or 100 mg once daily and 50 mg once daily orally or intravenously, respectively. CONCLUSIONS: Lower doses and longer dosing intervals should be considered for patients with liver dysfunction. TBIL-based dosing regimens provide a practical strategy for achieving voriconazole therapeutic range and therefore maximizing treatment outcomes.

Population pharmacokinetics of the anti-PD-1 antibody camrelizumab in patients with multiple tumor types and model-informed dosing strategy.

Camrelizumab, a programmed cell death 1 (PD-1) inhibitor, has been approved for the treatment of patients with relapsed or refractory classical Hodgkin lymphoma, nasopharyngeal cancer and non-small cell lung cancer. The aim of this study was to perform a population pharmacokinetic (PK) analysis of camrelizumab to quantify the impact of patient characteristics and to investigate the appropriateness of a flat dose in the dosing regimen. A total of 3092 camrelizumab concentrations from 133 patients in four clinical trials with advanced melanoma, relapsed or refractory classical Hodgkin lymphoma and other solid tumor types were analyzed using nonlinear mixed effects modeling. The PKs of camrelizumab were properly described using a two-compartment model with parallel linear and nonlinear clearance. Then, covariate model building was conducted using stepwise forward addition and backward elimination. The results showed that baseline albumin had significant effects on linear clearance, while actual body weight affected intercompartmental clearance. However, their impacts were limited, and no dose adjustments were required. The final model was further evaluated by goodness-of-fit plots, bootstrap procedures, and visual predictive checks and showed satisfactory model performance. Moreover, dosing regimens of 200 mg every 2 weeks and 3 mg/kg every 2 weeks provided similar exposure distributions by model-based Monte Carlo simulation. The population analyses demonstrated that patient characteristics have no clinically meaningful impact on the PKs of camrelizumab and present evidence for no advantage of either the flat dose or weight-based dose regimen for most patients with advanced solid tumors.

One-year outcomes of fixed-dosing Aflibercept therapy for pre treated and naive polypoidal choroidal vasculopathy patient.

BACKGROUND: Polypoidal choroidal vasculopathy (PCV) is a type of age-related macular degeneration that can cause permanent vision loss. The purpose of this paper was to report the one-year outcomes of fixed-dosing aflibercept therapy for the treatment of PCV. METHODS: This was a prospective, single-arm, interventional case series study of 25 PCV patients; 12 pre-treated and 13 treatment-naïve patients. The patients were treated and monitored for 12 months. Each patient was administered with an aflibercept (2.0 mg) injection every month for the first 3 months (the loading phase), and thereafter, once every 2 months. At every follow-up visit, best-corrected visual acuity (BCVA) test, fundus examination, and optical coherence tomography for measuring the central subfield macular thickness (CSMT) were performed. Fluorescein and indocyanine green angiography were conducted at baseline and at 4 and 12 months. RESULTS: After 12 months of aflibercept therapy, the mean BCVA of the patients significantly improved from 65.48 letters at baseline to 69.91 letters (p=0.001), and the CSMT significantly decreased from 406.92 um at baseline to 276.12 um (p< 0.001). Additionally, ten patients (40%) showed complete polyp regression. The treatment-naïve patients showed a statistically significant improvement in BCVA from 66.58 letters at baseline to 76.36 letters at 12 months, and a significant decrease in CSMT, from 462 to 243 um. In the pre-treated group, there was no change in BCVA (64.46 letters), and the decrease in CSMT from 356.08 to 303.69 um was not statistically significant. CONCLUSIONS: The fixed-dosing aflibercept regimen is effective for treating patients with PCV and is more effective in treatment-naïve patients than in pre-treated patients. TRIAL REGISTRATION: Clinical Research Information Service (CRiS), Republic of Korea. Identifer: KCT0005798, Registered: Jan 20, 2021. Retrospectively registered, URL: https://cris.nih.go.kr/cris/en/search/search_result_st01.jsp?seq=18546.

A real-world data approach to determine the optimal dosing strategy for pembrolizumab.

INTRODUCTION: Cancer drug therapy costs continue to rise and threaten the sustainability of Canada's public healthcare system. Previous studies have calculated potential savings utilizing different dosing regimens of cancer treatments. Our objectives were to determine the financial impact of drug wastage and to explore cost-effective dosing regimens for pembrolizumab. METHODS: This was a retrospective study reviewing data for non-small cell lung cancer and melanoma patients at all six BC Cancer Regional Centres during fiscal years 2017 and 2018. Pembrolizumab waste amounts recorded in pharmacy wastage logs were totalled. Estimates of the number of vials used were compared between vial sharing and non-vial sharing practices to determine the cost differences. Costs for dosing regimens used during fiscal years 2017 and 2018 were compared to 2 mg/kg weight-based dosing (to a maximum of 200 mg), 2 mg/kg dosing rounding down within 5% and 10%, and flat dosing of 200 mg. RESULTS: There were a total of 202 non-small cell lung cancer and 182 melanoma patients with 2948 doses dispensed. Documented wastage was valued at $1,829,047.44 (8.65%) and across all six centres, vial sharing could reduce costs by $3,207,600.00 using the 100 mg vials. Compared to fiscal years 2017 and 2018, 2 mg/kg dosing (to a maximum of 200 mg) was the most cost-effective, decreasing costs by $222,719.20; flat dosing of 200 mg was the most expensive, increasing costs by $6,625,260.40. CONCLUSIONS: Having smaller vial sizes, practicing vial sharing, and using weight-based dosing all improve cost savings. Further investigations on the allocation of resources to optimize drug use and minimize wastage are needed.

Treatment of idiopathic nephrotic syndrome with two steroid dosing regimens - one-year observational study.

INTRODUCTION: The aim of the study was to compare the first year of disease in children with idiopathic nephrotic syndrome (INS) treated according to two prednisone dosing regimens: a weight-based schedule (2 mg/kg/24 h in the 1st month, 2 mg/kg/48 h in the 2nd month, with dose tapering during the following 4 months), and a body surface area (BSA)-based schedule (60 mg/m2/24 h in the 1st month, 40 mg/m2/48 h in the 2nd month, with dose tapering during the following 4 months). MATERIAL AND METHODS: In 2 groups of children treated with weight- and BSA-based regimens (20 patients, 3.13 ±1.01 years, treated in 2010-2013 and 20 patients, 5.13 ±2.86 years, treated in 2014-2016) clinical and anthropometrical parameters, number of INS relapses, total prednisone dose (mg/kg/year), and steroid adverse effects were compared during the first year of disease. RESULTS: Children treated with the weight-based steroid regimen received a higher total annual prednisone dose (259.06 ±79.54 vs. 185.83 ±72.67 mg/kg/24 h, p = 0.004) and had a shorter (though not significantly) period without prednisone (38.25 ±55.83 vs. 75.90 ±73.06 days, p = 0.062) compared to patients treated with the BSA-based regimen. There was no difference in number of relapses between groups (2.20 ±1.64 vs. 1.60 ±1.67, p = 0.190) but more patients relapsed in the weight-based group (19/20 vs. 13/20, p = 0.044). No differences in Z-score values of height, weight, and body mass index (BMI) were observed. No steroid-related adverse events were noted except for arterial hypertension (4/20 vs. 5/20 patients, p = 1.000). CONCLUSIONS: The BSA-based regimen of prednisone dosing in children with INS reduces exposure to steroids and risk of relapse, as well as increases days off steroids in the first year compared to the weight-based regimen with a high second-month dose.

[Antiangiogenic therapy of neovascular age-related macular degeneration]. / Antiangiogennaya terapiya neovaskulyarnoi vozrastnoi makulyarnoi degeneratsii.

The problem associated with the prevalence of retinal diseases, and age-related macular degeneration (AMD) in particular, is undoubtedly relevant. This aspect is based on steadily growing statistics on morbidity, a high number of randomized controlled trials (RCT) and published real world data (RWD). The analysis of RCT results being published by researchers on 15.05.19 showed 2915 studies were registered on the subject of retinal diseases; that exceeds the number of studies on glaucoma by approximately 1.38 times (2118 studies) and conjunctival lesions by 2.37 times (1230 studies). AMD is one of the leading causes of irreversible vision loss and blindness; its neovascular form leads to blindness in 80-90% of all cases. Even though the topic of nAMD therapy is widely highlighted in modern ophthalmology, today there are many aspects that require targeted solutions. The main controversial issues that determine the complexity of therapy and patient management include discrepancies in determination of reference points (disease activity criteria) for implementation of anti-VEGF dosing regimens, patients' compliance, prioritization issues in treatment, its continuity with potential for the increase of intervals between injections and monitoring visits.

Population pharmacokinetics and dose optimization of ceftriaxone for children with community-acquired pneumonia.

PURPOSE: To assess ceftriaxone population pharmacokinetics in a large pediatric population and describe the proper dose for establishing an optimized antibiotic regimen. METHODS: From pediatric patients using ceftriaxone, blood samples were obtained and the concentration was measured using high-performance liquid chromatography ultraviolet detection. The NONMEM software program was used for population pharmacokinetic analysis, for which data from 99 pediatric patients (2 to 12 years old) was collected and 175 blood concentrations were obtained. RESULTS: The best fit with the data was shown by the one-compartment model with first-order elimination. According to covariate analysis, weight had a significant impact on the clearance of ceftriaxone. Using Monte Carlo simulation, in a pediatric population with community-acquired pneumonia, a dose regimen of 100 mg/kg every 24 h produced satisfactory target attainment rates while remaining within the required minimum inhibitory concentration (2 mg/L). CONCLUSION: Population pharmacokinetics of ceftriaxone was evaluated in children and an optimum dosing regimen was constructed on the basis of the pharmacokinetics-pharmacodynamics model-based approach.

Use of cidofovir with extracorporeal membrane oxygenation to treat adenovirus-associated acute respiratory distress syndrome in paediatric patients- a case series.

WHAT IS KNOWN AND OBJECTIVE: Reports of cidofovir dosing with extracorporeal membrane oxygenation (ECMO) support are limited. This case series describes our clinical experience and provides a literature review regarding cidofovir dosing in paediatric patients requiring ECMO support. CASE SUMMARY: Three patients with adenovirus-associated acute respiratory distress syndrome (ARDS) were treated with cidofovir while requiring ECMO support. A 27-month-old patient was treated with cidofovir 1 mg/kg/dose three times weekly, and a 19-month-old patient and an 18-year-old patient were treated with cidofovir 5 mg/kg/dose weekly. WHAT IS NEW AND CONCLUSION: This case series describes the dosing and positive clinical response of cidofovir in paediatric patients with adenovirus-associated ARDS requiring ECMO support.

Dosing inaccuracy with enteral use of ENFit ® low-dose tip syringes: The risk beyond oral adapters.

WHAT IS KNOWN AND OBJECTIVE: As the global adoption of ENFit-compatible syringes becomes more widespread, it is important for syringe users to understand the risk of dosing inaccuracy for both the oral and enteral routes of use. Describing the risk of dosing inaccuracy specifically related to route of use is important to the end users' understanding of the clinical impact of device changes. The objective of this study was to compare the performance of female design ENFit low dose tip (LDT) syringes when used for enteral medication administration to the syringe performance during oral administration conditions. METHODS: This study was a secondary analysis of a prospective study conducted at the University of Florida Health Shands Hospital in conjunction with the University of Florida College of Pharmacy. Dosing variance (DV) up to 10% for low-risk medications and DV up to 5% is the target for high-risk medication administration is considered acceptable. The primary outcome was the frequency of administration volumes exceeding 10% of the expected amount when using the ENFit LDT syringe for both oral and enteral medication administration. Secondarily, the performance of standard ENFit syringes and the frequencies of DV exceeding 5 and 10% were also evaluated in the same conditions. RESULTS AND DISCUSSION: A total of 264 tests were evaluated (ENFit LDT, n = 210; ENFit standard tip, n = 54). Using the LDT syringe for the enteral route resulted in statistically significant higher rates of unacceptable dosing variance >10% when compared to the oral application (26.9% vs 12.9%, P = .01). The frequency of LDT syringe DV >5% was significantly greater than >10% variance, regardless of oral or enteral use. Standard ENFit syringes had overall fewer tests with unacceptable dosing variance and showed no difference in performance between applications. WHAT IS NEW AND CONCLUSIONS: This study raises additional clinical concerns specifically related to the enteral use of ENFit LDT syringes within commonly accepted dosing variance ranges. Enteral and oral application of LDT syringes yield unacceptably high rates of dosing variance for high risk medications with narrow therapeutic index.

Physiologically Based Pharmacokinetic Modeling of Oxycodone in Children to Support Pediatric Dosing Optimization.

PURPOSE: Physiologically-based pharmacokinetic (PBPK) modeling offers a unique modality to predict age-specific pharmacokinetics. The objective of this study was to assess the ability of PBPK model to predict plasma exposure of oxycodone, a widely used opioid for pain management, in adults and children. METHODS: A full PBPK model of oxycodone following intravenous and oral administration was developed using a 'bottom-up' and 'top-down' combined strategy. The model was then extrapolated to pediatrics through a reasonable scaling method. The adult and pediatric model was evaluated using data from 17 clinical PK studies by testing predicted/observed goodness of fit. The mean fold error for PK parameters was calculated. Finally, we used the validated PBPK model to visualize adult-children dose conversion for oxycodone. RESULTS: The developed PBPK model successfully predicted the oxycodone disposition in adults, wherein the predicted versus observed AUC, Cmax, and tmax were within 0.90 to 1.20-fold difference. After scaling anatomy/physiology, protein binding, and clearance, the model showed satisfactory prediction performance for pediatric populations as predicted AUC were within the 1.50-fold range of the observed values. According to the application of PBPK model, we found that different intravenous doses should be given in children of different ages compared to a standard 0.1 mg/kg in adults, while a progressive increasing dose with age growth following oral administration is recommended for children. CONCLUSIONS: The current example provides the opportunity for using the PBPK model to guide dose adjustment of oxycodone in the design of future pediatric clinical studies.

Pharmacokinetic-pharmacodynamic modelling for the determination of optimal dosing regimen of florfenicol in Nile tilapia (Oreochromis niloticus) at different water temperatures and antimicrobial susceptibility levels.

Optimized dosing regimen is key to the effective use of antibacterials and to minimizing drug-related side effects. The current study established a pharmacokinetic-pharmacodynamic (PK-PD) model for the determination of optimal antibacterial dosing regimen in fish taken into consideration the temperature-dependent PK and the pathogen-dependent antimicrobial susceptibility, using florfenicol (FF) in Nile tilapia as an example. The calculated optimal dosages significantly varied by temperature and target MIC levels, ranging from 2.23 (MIC 1 µg/ml at 24°C) to 34.88 mg kg-1  day-1 (MIC 4 µg/ml at 32°C). The appropriateness of the calculated dosages was successfully verified by the in vivo studies. After 5 days of oral administration of the calculated optimal dosage at 24°C, the predicted plasma drug values were in line with the mean observed Cmin(ss) while at 28 and 32°C underestimation of the Cmin(ss) in a dose-dependent manner was observed and likely due to the occurrence of non-linear PK at high dosages. The averaged serum protein binding of FF was 19.1%. Our results demonstrated the appropriateness and clinical applicability of the developed PK-PD approach for the determination of optimal dosing regimens at given temperatures and MICs. Saturation metabolism and PK non-linearity of FF in tilapia warrant further study.