Impact of antimicrobial stewardship program-driven educational intervention for vancomycin loading dose on mortality

BACKGROUND

Although the loading dose (LD) of vancomycin (VCM) contributes to its efficacy, it may not be conducted adequately. Herein, the objective was to evaluate the effect of LD on patient prognosis using therapeutic drug monitoring by pharmacists and elucidate the impact of an antimicrobial stewardship program (ASP)-driven educational intervention on the LD implementation rate and patient prognosis.

MATERIALS AND METHODS

First, a retrospective cohort study was conducted involving 121 adult patients administered with VCM and compared with 28-day mortality in LD and non-LD groups. To avoid confounding, the propensity score method was employed. Second, post-training with ASP-driven lectures, a questionnaire survey was conducted for healthcare workers, including physicians, nurses, and pharmacists. The rates of VCM LD implementation and 28-day mortality were compared during a period of one year and 9 months between the pre-ASP (n = 38) and post-ASP (n = 33) groups.

RESULTS

After propensity score matching, the 28-day mortality in the LD group was significantly improved, suggesting that the early increase in blood levels of VCM due to an LD is an important factor influencing patient prognosis. After the lecture, a questionnaire survey revealed that the understanding rates of "well" and "slightly well" for educational lectures exceeded 80% of all healthcare workers. The rate of LD implementation significantly increased to 63.6% (21/33) in the post-ASP group compared with 31.6% (12/38) in the pre-ASP group (p = 0.007), and the 28-day mortality declined from 23.7% (9/38) to 6.1% (2/33) (p = 0.041).

CONCLUSION

This method of ASP-driven educational intervention would facilitate LD implementation, improving patient prognosis.

Trends in teicoplanin loading dose implementation from 2010 to 2019 and evaluation of safety and efficacy factors: a retrospective cohort study based on a Japanese administrative claims database

BACKGROUND

The loading dose of teicoplanin (TEIC) is recommended for implementation. However, there is significant discrepancy between the dose settings in the package insert and, in the guidelines, and the actual status of loading doses in Japan is unclear. Furthermore, TEIC causes liver injury as side effect. Although the risk of developing liver injury has not been reported to be increased following a loading dose based on the guidelines, there is a lack of reports in large populations. Therefore, we evaluated the trend in the loading dose and factors affecting the efficacy and safety of TEIC administration.

METHODS

A Japanese administrative claims database was used in this study. Trends in loading doses were evaluated in target populations administered TEIC between 2010 and 2019. Patient characteristics were adjusted by propensity score matching based on the guideline group (total dose of 3 days > 1,600 mg) and non-guideline group (≤ 1,600 mg) of the loading dose. Finally, univariable and multivariable conditional logistic regression analysis was performed to evaluate factors affecting 30-day mortality and liver injury.

RESULTS

A total of 10,030 patients were selected based on these criteria. The proportion of loading doses based on the recommended guidelines showed an increase over time, regardless of the implementation of therapeutic drug monitoring (TDM), but especially so in cases where TDM was implemented, the loading doses were administered in accordance with the recommendations of the guidelines. Conditional logistic regression analysis showed a relationship between drug management and guidance fees (odds ratio [OR]: 0.45, 95% confidence interval [CI]: 0.36‒0.55), a reimbursement indicating pharmacist intervention, and a reduction in 30-day mortality. In addition, loading doses based on the recommended guidelines had no influence on liver injury, and other factors were not significantly associated with increased incidence of liver injury.

CONCLUSION

Thus, this study implies the benefits of pharmacological management as indicated by drug management and guidance fee and supports the implementation of loading doses based on the guideline on TEIC administration.

Comparative Safety and Effectiveness of Loading Doses of P2Y12 Inhibitors in Patients Undergoing Elective PCI: a Network Meta-analysis

PURPOSE

Effective platelet inhibition prior to elective percutaneous coronary intervention (PCI) reduces the risk of ischemic complications. Newer P2Y12 inhibitors are preferred agents over clopidogrel for patients presenting with the acute coronary syndrome. However, the comparative efficacy and safety of them over clopidogrel in elective PCI is unclear. We performed a network meta-analysis to compare the safety and efficacy of loading strategies of P2Y12 inhibitors in patients undergoing elective PCI.

METHODS

We conducted a systematic review of randomized controlled trials (RCT) up to June 2021 to compare the safety and effectiveness of different loading strategies of P2Y12 inhibitors before elective PCI. The endpoints of interest were overall mortality, rates of myocardial infarction (MI), stroke, revascularization, and major bleeding. Random effects model using the frequentist approach was used to perform a network meta-analysis using R software.

RESULTS

Five trials with a total of 5194 patients were included in our analysis. For ischemic outcomes, including MI, stroke, and revascularization, prasugrel had the most favorable trend. However, clopidogrel had the highest probability of being most effective for major bleeding and all-cause mortality. None of these trends was statistically significant due to lack of power for each outcome.

CONCLUSION

Although prasugrel and ticagrelor are known as more potent antiplatelet agents, their effects in preventing MI and stroke are marginal and do not translate into improved overall mortality and bleeding compared with clopidogrel.

Association between P2Y12 inhibitor reloading and in-hospital outcomes for patients with non-ST-segment elevation acute coronary syndrome already on chronic P2Y12 receptor inhibitors therapy in China: findings from the CCC-ACS (improving care for cardiovascular disease in China-acute coronary syndrome) project

BACKGROUND

The association between P2Y12 receptor inhibitors reloading and in-hospital outcomes in non-ST-segment elevation acute coronary syndrome (NSTEACS) patients who were on chronic P2Y12 receptor inhibitors therapy remained underdetermined.

METHODS

The Improving Care for Cardiovascular Disease in China-Acute Coronary Syndrome (CCC-ACS project) is a national registry active from November 2014 to December 2019. 4790 NSTEACS patients on chronic P2Y12 receptor inhibitors therapy were included. Cox proportional hazard models, Kaplan-Meier curves, and subgroup analyses were conducted.

RESULTS

The NSTEACS patients who received reloading of P2Y12 receptor inhibitors were younger and had fewer comorbid conditions. The reloading group had a lower risk of major adverse cardiac events (MACE) (0.51% vs. 1.43%, P = 0.007), and all-cause death (0.36% vs. 0.99%, P = 0.028), the risks of myocardial infarction and major bleeding were not significantly different between patients with and without reloading. In survival analysis, a lower cumulative risk of MACE could be identified (Log-rank test, P = 0.007) in reloading group. In the unadjusted Cox model, reloading P2Y12 receptor inhibitors was associated with a decreased risk of MACE [HR, 0.35; 95% CI 0.16-0.78; (P = 0.010)] and all-cause death [HR, 0.37; 95% CI 0.14-0.94; (P = 0.036)]. Reloading of P2Y12 receptor inhibitors was associated with a decreased risk of MACE in most of the subgroups.

CONCLUSIONS

In NSTEACS patients already taking P2Y12 receptor inhibitors, we observed a decreased risk of in-hospital MACEs and all-cause mortality and did not observe an increased risk of major bleeding, with reloading. The differential profile in the two groups might influence this association and further studies are warranted.

CLINICAL TRIAL REGISTRATION

https://www.

CLINICALTRIALS

gov (Unique identifier: NCT02306616, date of first registration: 03/12/2014).

Individualized optimization of colistin loading doses

Colistin remains one of the few available options for the treatment of infections caused by resistant bacteria. Pharmacokinetic (PK) studies have been successful in estimating the appropriate colistin methanesulfonate (CMS) dose to achieve a target colistin concentration. Currently, there is a consensus that the dose of CMS should vary according to the patient renal function since CMS is mainly eliminated by renal route. For this same reason, the loading dose should vary according to the patient's renal capacity; however, this is not the current clinical practice. In this study we develop a framework to determine two key parameters for the loading dose regimen: (1) the optimal dose according to the characteristics (renal function and weight) of the patient; (2) the waiting time before the maintenance dose. Based on a previous PK model, our framework allows a fast parameter sweep so as to select optimal loading dose and waiting time minimizing the deviation between the plasma concentration and a target value. The results showed that patients presenting low creatinine clearance (CrCL) should receive a lower CMS loading dose with longer interval to start maintenance treatment to avoid nephrotoxic colistin concentrations. In cases of high CrCL, the dose should be higher and the interval to the next dose shorter to avoid subtherapeutic concentrations. Optimization of the loading dose should considerably improve colistin therapy, as the target concentration is reached more quickly, without reaching toxic values.

The effect of a loading dose of meropenem on outcomes of patients with sepsis treated by continuous renal replacement: study protocol for a randomized controlled trial

Background

Sepsis and continuous renal replacement therapy (CRRT) are both responsible for the alterations of the pharmacokinetics of antibiotics. For patients with sepsis receiving CRRT, the serum concentrations of meropenem in the early phase (< 48 h) was significantly lower than that in the late phase (> 48 h). This current trial aimed to investigate whether administration of a loading dose of meropenem results in a more likely achievement of the pharmacokinetic (PK)/pharmacodynamics (PD) target (100% fT > 4 × MIC) and better therapeutic results in the patients with sepsis receiving CRRT.

Methods

This is a single-blinded, single-center, randomized, controlled, two-arm, and parallel-group trial. This trial will be carried out in Guangzhou First People’s Hospital, School of Medicine, South China University of Technology Guangdong, China. Adult patients (age ≥ 18 years) with critical sepsis or sepsis-related shock receiving CRRT will be included in the study. The subjects will be assigned to the control group and the intervention group (LD group) randomly at a 1:1 ratio, the estimated sample size should be 120 subjects in each group. In the LD group, the patient will receive a loading dose of 1.5-g meropenem resolved in 30-ml saline which is given via central line for 30 min. Afterward, 0.75-g meropenem will be given immediately for 30 min every 8 h. In the control group, the patient will receive 0.75-g meropenem for 30 min every 8 h. The primary objective is the probabilities of PK/PD target (100% fT > 4 × MIC) achieved in the septic patients who receive CRRT in the first 48 h. Secondary objectives include clinical cure rate, bacterial clearance rate, sepsis-related mortality and all-cause mortality, the total dose of meropenem, duration of meropenem treatment, duration of CRRT, Sequential Organ Failure Assessment (SOFA), C-reactive protein levels, procalcitonin levels, white blood cell count, and safety.

Discussion

This trial will assess for the first time whether administration of a loading dose of meropenem results in a more likely achievement of the PK/PD target and better therapeutic results in the patients with sepsis receiving CRRT. Since CRRT is an important therapeutic strategy for sepsis patients with hemodynamic instability, the results from this trial may help to provide evidence-based therapy for septic patients receiving CRRT.

Trial registration

Chinese Clinical Trials Registry, ChiCTR2000032865. Registered on 13 May 2020, http://www.chictr.org.cn/showproj.aspx?proj=53616.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-022-06264-2.

The necessity of a loading dose when prescribing intravenous colistin in critically ill patients with CRGNB-associated pneumonia: a multi-center observational study

Background

The importance or necessity of a loading dose when prescribing intravenous colistin has not been well established in clinical practice, and approximate one-third to half of patients with carbapenem-resistant gram-negative bacteria (CRGNB) infection did not receive the administration of a loading dose. The aim of this study is to investigate the efficacy and risk of acute kidney injury when prescribing intravenous colistin for critically ill patients with nosocomial pneumonia caused by CRGNB.

Methods

This was a multicenter, retrospective study that recruited ICU-admitted patients who had CRGNB-associated nosocomial pneumonia and were treated with intravenous colistin. Then, we classified the patients into colistin loading dose (N = 85) and nonloading dose groups (N = 127). After propensity-score matching for important covariates, we compared the mortality rate, clinical outcome and microbiological eradication rates between the groups (N = 67).

Results

The loading group had higher percentages of patients with favorable clinical outcomes (55.2% and 35.8%, p = 0.037) and microbiological eradication rates (50% and 27.3%, p = 0.042) at day 14 than the nonloading group. The mortality rates at days 7, 14 and 28 and overall in-hospital mortality were not different between the two groups, but the Kaplan–Meier analysis showed that the loading group had a longer survival time than the nonloading group. Furthermore, the loading group had a shorter length of hospital stay than the nonloading group (52 and 60, p = 0.037). Regarding nephrotoxicity, there was no significant difference in the risk of developing acute kidney injury between the groups.

Conclusions

The administration of a loading dose is recommended when prescribing intravenous colistin for critically ill patients with nosocomial pneumonia caused by CRGNB.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-03947-9.

Enhanced loading dose of teicoplanin for three days is required to achieve a target trough concentration of 20 μg/mL in patients receiving continuous venovenous haemodiafiltration with a low flow rate

INTRODUCTION

Because of its lower risk of renal toxicity than vancomycin, teicoplanin is the preferred treatment for methicillin-resistant Staphylococcus aureus infection in patients undergoing continuous venovenous haemodiafiltration (CVVHDF) in whom renal function is expected to recover. The dosing regimen for achieving a trough concentration (C_min) of ≥20 μg/mL remains unclear in patients on CVVHDF using the low flow rate adopted in Japan.

METHODS

The study was conducted in patients undergoing CVVHDF with a flow rate of <20 mg/kg/h who were treated with teicoplanin. We adopted three loading dose regimens for the initial 3 days: the conventional regimen, a high-dose regimen (four doses of 10 mg/kg), and an enhanced regimen (four doses of 12 mg/kg). The initial C_min was obtained at 72 h after the first dose.

RESULTS

Overall, 60 patients were eligible for study inclusion. The proportion of patients achieving the C_min target was significantly higher for the enhanced regimen than for the high-dose regimen (52.9% versus 8.3%, p = 0.003). In multivariate analysis, the enhanced regimen (odds ratio [OR] = 39.93, 95% confidence interval [CI] = 5.03-317.17) and hypoalbuminaemia (OR = 0.04, 95% CI = 0.01-0.44) were independent predictors of the achievement of C_min ≥ 20 μg/mL.

CONCLUSIONS

An enhanced teicoplanin regimen was proposed to treat complicated or invasive infections by methicillin-resistant Staphylococcus aureus in patients receiving CVVHDF even with a low flow rate.

The impact of delayed anti-vascular endothelial growth factor treatment for retinal diseases during the COVID-19 lockdown

Purpose

: To assess the clinical status of treatment-naive patients who had to delay 3-dose loading anti-VEGF (anti-vascular endothelial growth factor) injections during the COVID-19 lockdown, and to evaluate the effect of the delayed visual acuity treatment on spectral domain optical coherence tomography (SD-OCT) parameters.

Method

: A total of 55 eyes of 46 patients who were received in the study period participated in this retrospective study, including 28 patients (37 eyes) with diabetic macular edema (DME), 11 patients (11 eyes) with retinal vein occlusion (RVO), and 7 patients (7 eyes) with wet age-related macular degeneration (wet-AMD). The patients were diagnosed with DME, RVO, or wet-AMD in February 2020 and had planned 3-dose loading injections in March, April, and May 2020, but could not be injected due to the COVID-19 pandemic.

Results

: From the patients’ initial examination in February 2020, the mean best corrected visual acuity (BCVA) was 0.72 ± 59 logMAR. After the patients’ lockdown visit in July 2020, the mean BCVA was 0.76 ± 64 logMAR. BCVA was stable in 11 eyes, decreased in 12 eyes, and increased in 14 eyes for patients with DME. BCVA was stable in 6, decreased in 3, and increased in 2 eyes for patients with RVO, and it was stable in 4 eyes and decreased in 3 eyes for patients with wet-AMD.

Conclusion

: We concluded that 6-month delay in treatment of DME patients with non-proliferative DRP had no adverse effect on the visual acuity. However, the loading dose in wet-AMD and RVO patients should be applied as soon as possible.

Efficacy of a 3-day pretravel schedule of tafenoquine for malaria chemoprophylaxis: a network meta-analysis

BACKGROUND

Chemoprophylaxis with weekly doses of tafenoquine (200 mg/day for 3 days before departure [loading dose], 200 mg/week during travel and 1-week post-travel [maintenance doses]) is effective in preventing malaria. Effectiveness of malaria chemoprophylaxis drugs in travellers is often compromised by poor compliance. Shorter schedules that can be completed before travel, allowing 'drug-free holidays', could increase compliance and thus reduce travel-related malaria. In this meta-analysis, we examined if a loading dose of tafenoquine alone is effective in preventing malaria in short-term travellers.

METHODS

Four databases were searched in November 2020 for randomized controlled trials (RCTs) that assessed efficacy and/or safety of tafenoquine for chemoprophylaxis. Network meta-analysis using the generalized pair-wise modelling framework was utilized to estimate the odds ratio (OR) of malaria infection in long-term (>28 days) and short-term (≤28 days) travellers, as well as adverse events (AEs) associated with receiving loading dose of tafenoquine alone, loading dose of tafenoquine followed by maintenance doses, loading dose of mefloquine followed by maintenance doses, or placebo.

RESULTS

Nine RCTs (1714 participants) were included. In long-term travellers, compared to mefloquine, tafenoquine with maintenance doses (OR = 1.05; 95% confidence interval [CI]: 0.44-2.46) was equally effective in preventing malaria, while there was an increased risk of infection with the loading dose of tafenoquine alone (OR = 2.89; 95% CI: 0.78-10.68) and placebo (OR = 62.91; 95% CI: 8.53-463.88). In short-term travellers, loading dose of tafenoquine alone (OR = 0.98; 95% CI: 0.04-22.42) and tafenoquine with maintenance doses (OR = 1.00; 95% CI: 0.06-16.10) were as effective as mefloquine. The risk of AEs with tafenoquine with maintenance doses (OR = 1.03; 95% CI: 0.67-1.60) was similar to mefloquine, while loading dose of tafenoquine alone (OR = 0.58; 95% CI: 0.20-1.66) was associated with lower risk of AEs, although the difference was not statistically significant.

CONCLUSIONS

For short-term travellers, loading dose of tafenoquine alone was equally effective, had possibly lower rate of AEs, and likely better compliance than standard tafenoquine or mefloquine chemoprophylaxis schedules with maintenance doses. Studies are needed to confirm if short-term travellers remain free of infection after long-term follow-up.

REGISTRATION

The meta-analysis was registered in PROSPERO (CRD42021223756).

HIGHLIGHT

Tafenoquine is the latest approved drug for malaria chemoprophylaxis. A loading dose of tafenoquine (200 mg/day for 3 days before departure) is as effective in preventing malaria in short-term (≤28 days) travellers as chemoprophylaxis schedules of tafenoquine or mefloquine with maintenance doses, allowing travellers to have a 'drug-free holiday'.

Hemoadsorption with CytoSorb® and the early course of linezolid plasma concentration during septic shock

Hemoadsorption with CytoSorb^® becomes increasingly established in treatment of various, predominantly inflammation-associated diseases. In septic shock, results suggest improvements in hemodynamics and organ function. However, little is known about the in vivo adsorption properties for various antibiotics. We present the case of a 61-year-old female patient with known Ulrich Turner syndrome who treated supportively with CytoSorb^® and with linezolid due to a Staphylococcus epidermidis bloodstream infection as part of her intensive care treatment for septic shock. After establishment of a new adsorber, 600 mg of linezolid administered over 1 h. Linezolid levels measured before adsorber inlet (c_pre) and after adsorber outlet (c_post) at 0, 15, 60, 120 and 480 min after starting infusion. Out of the ten samples, only the cpre samples 60 min (3.25 mg/l) and 120 min (4.7 mg/l) showed sufficiently high linezolid levels (therapeutic range 3–9 mg/l). After 480 min, cpre decreased to 2.8 mg/l, cpost increased to 1.85 mg/l, and thus clearance decreased to 67.86 ml/min (from 200 ml/min at 60 min), with greatly reduced adsorption capacity of CytoSorb^® after 8 h. A loading dose (additional 600 mg) would have been urgently needed. Linezolid therapy under hemadsorption with CytoSorb^® requires a clear indication and close monitoring of levels to avoid underdosing.

No increased acute kidney injury rate through giving an intravenous colistin loading dose in pediatric patients

OBJECTIVES

A colistin loading dose is required to achieve adequate drug exposure for the treatment of multidrug-resistant Gram-negative bacteria. However, data on acute kidney injury (AKI) rates associated with this approach in children have been unavailable. The aim of this study was to examine AKI rates in children who were prescribed a colistin loading dose.

METHODS

A retrospective study was conducted in patients aged 1 month to 18 years who had received intravenous colistin for ≥48 h. Loading dose (LD) was defined as colistin methanesulfonate at 4-5 mg of colistin base activity/kg/dose. AKI was defined according to KDIGO serum creatinine (SCr) criteria - SCr ≥ 1.5 times the baseline, measured 3-7 days after colistin initiation. Augmented renal clearance (ARC) was defined as an estimated glomerular filtration rate (eGFR) >150 mL/min/1.73 m². The rates of AKI were compared between children receiving or not receiving an LD, and between different eGFR groups.

RESULTS

In total, 181 children were enrolled. The mean age was 4.3 years (95% confidence interval [CI], 3.6-4.9 years). Ninety-five of the subjects (52.5%) were male. There were 157 children with a baseline eGFR of ≥ 80 mL/min/1.73 m². The overall AKI rate within the first week in this group was 20.4% (95% CI, 14.4-27.6%): LD, 16.1% vs no LD, 23.2% (p = 0.29). Subgroup analysis, excluding patients with ARC, showed a lower AKI rate of 12.8% (95% CI, 6.8-21.3%): LD, 9.7% vs no LD, 14.3% (p = 0.53).

CONCLUSIONS

AKI rate was not different among children who received an intravenous colistin loading dose. This approach should be implemented to ensure the necessary drug exposure required for good treatment outcomes.

Safety, tolerability, and pharmacokinetics of weight-based IV loading dose of lacosamide in the ICU

Among the newer antiseizure medications, lacosamide (LCM) has been increasingly used for acute seizures and status epilepticus in intensive care unit (ICU). We reviewed retrospectively weight-based dosing of IV LCM in patients admitted to ICU with acute seizures and status epilepticus. We have analyzed 354/382 patient treated with IV LCM in ICU during the years 2013-2016. Data collected were age, total body weight, body mass index (BMI), loading dose, post-IV infusion LCM blood level, duration of infusion, blood pressure, heart rate, oxygen saturation, mean arterial pressures, and documented initiation of pressor agents during or within in 30 min of infusion. Larger doses >8 mg/kg of IV LCM that can be safely administered in ICU patients produce effective plasma levels of 15-20 μg/ml with relatively constant volume of distribution.

P2Y12 inhibitor loading dose before catheterization in ST-segment elevation myocardial infarction: Is this the best strategy?

INTRODUCTION AND OBJECTIVES

In ST-segment elevation myocardial infarction (STEMI) the benefit of dual antiplatelet therapy is unequivocal, but the optimal time to administer the loading dose (LD) of a P2Y₁₂ inhibitor is the subject of debate and disagreement. The main aim of this study was characterize current practice in Portugal and to assess the prognostic impact of P2Y₁₂ inhibitor LD administration strategy, before versus during or after primary percutaneous coronary intervention (PCI).

METHODS

This multicenter retrospective study based on the Portuguese National Registry on Acute Coronary Syndromes included patients with STEMI and PCI performed between October 1, 2010 and September 19, 2017. Two groups were established: LD before PCI (LD-PRE) and LD during or after PCI (LD-CATH).

RESULTS

A total of 4123 patients were included, 66.3% in the LD-PRE group and 32.4% in the LD-CATH group. Prehospital use of a P2Y₁₂ inhibitor was a predictor of the composite bleeding endpoint (major bleeding, need for transfusion or hemoglobin [Hb] drop >2g/dl), Hb drop >2g/dl and reinfarction. There were no differences between groups in major adverse events (MAE) (in-hospital mortality, reinfarction and stroke) or in-hospital mortality.

CONCLUSIONS

Prehospital use of a P2Y₁₂ inhibitor was associated with an increased risk of bleeding, predicting the composite bleeding outcome and Hb drop >2g/dl, with no differences in mortality or MAE, calling into question the benefit of this strategy.

What is the optimal loading dose of broad-spectrum β-lactam antibiotics in septic patients? Results from pharmacokinetic simulation modelling

Optimal loading doses of β-lactams to rapidly achieve adequate drug concentrations in critically ill patients are unknown. This was a post-hoc analysis of a prospective study that evaluated broad-spectrum β-lactams [piperacillin (PIP), ceftazidime (CAZ), cefepime (FEP) and meropenem (MEM)] pharmacokinetics (PKs) in patients with sepsis or septic shock (n = 88). Monte Carlo simulation was performed for 1000 virtual patients using specific sets of covariates for various dosing regimens and different durations of administration. Pharmacodynamic (PD) targets were considered as drug concentrations exceeding at least 50% of time above four times the minimum inhibitory concentration (T_>4 × MIC) of Pseudomonas aeruginosa, according to EUCAST criteria, for PIP, 70%T_>4 × MIC for CAZ and FEP and 40%T_>4 × MIC for MEM. The probability of target attainment (PTA) was derived by calculating the percentage of patients who attained the PK/PD target at each MIC. The optimal loading dose was defined as the one associated with a ≥90% probability to achieve the PD targets. Our simulation model identified an optimal loading dose for PIP of 8 g given as a 3-h infusion (PTA of 96.2%), for CAZ and FEP of 4 g given as a 3-h infusion (PTA of 96.5% and 98.4%, respectively), and for MEM of 2 g given as a 30-min infusion (PTA of 93.4%), with the following antibiotic dose administered 6 h thereafter regardless of the drug. A higher first dose of broad-spectrum β-lactams should be given to adequately treat less-susceptible pathogens in septic patients. These findings need to be validated in a prospective study.

Clinical efficacy and safety in patients treated with teicoplanin with a target trough concentration of 20 μg/mL using a regimen of 12 mg/kg for five doses within the initial 3 days

Background

A trough concentration (C_min) ≥20 μg/mL of teicoplanin is recommended for the treatment of serious methicillin-resistant Staphylococcus aureus (MRSA) infections. However, sufficient clinical evidence to support the efficacy of this target C_min has not been obtained. Even though the recommended high C_min of teicoplanin was associated with better clinical outcome, reaching the target concentration is challenging.

Methods

Pharmacokinetics and adverse events were evaluated in all eligible patients. For clinical efficacy, patients who had bacteremia/complicated MRSA infections were analyzed. The primary endpoint for clinical efficacy was an early clinical response at 72–96 h after the start of therapy. Five dosed of 12 mg/kg or 10 mg/kg was administered as an enhanced or conventional high loading dose regimen, respectively. The C_min was obtained at 72 h after the first dose.

Results

Overall, 512 patients were eligible, and 76 patients were analyzed for treatment efficacy. The proportion of patients achieving the target C_min range (20–40 μg/mL) by the enhanced regimen was significantly higher than for the conventional regimen (75.2% versus 41.0%, p < 0.001). In multivariate analysis, C_min ≥ 20 μg/mL was an independent factor for an early clinical response (odds ratio 3.95, 95% confidence interval 1.25–12.53). There was no significant difference in the occurrence of adverse events between patients who did or did not achieve a C_min ≥ 20 μg/mL.

Conclusion

A target C_min ≥ 20 μg/mL might improve early clinical responses during the treatment of difficult MRSA infections using 12 mg/kg teicoplanin for five doses within the initial 3 days.

Assessment of micafungin loading dosage regimens against Candida spp. in ICU patients by Monte Carlo simulations

OBJECTIVE

To assess the efficacy of loading dose on micafungin by simulating different dosage regimens.

METHODS

A published study of micafungin in ICU patients was employed to simulate nine different dosage regimens which were sorted out three groups in terms of three maintenance doses. Using pharmacokinetic parameters and pharmacodynamic data, 5000-subject Monte Carlo simulations were conducted to simulate concentration-time profiles of micafungin, calculate probabilities of target attainment (PTAs), and cumulative fractions of response (CFRs) in terms of AUC/MIC targets. PTAs were calculated using AUC/MIC cut-offs: 285 (Candida parapsilosis), 3000 (all Candida spp.), and 5000 (non-parapsilosis Candida spp.). PTA or CFR > 90% was considered optimal for a dosage regimen.

RESULTS

The concentration-time profiles of micafungin-simulated dosage regimens were obtained. PTA values were over 90% while applying the loading dose in each group of regimens: for Candida albicans and Candida glabrata (AUC/MIC = 5000), all regimens with loading dose provided PTAs of ≥ 90% for MIC ≤ 0.008 mg/L. The PTAs (AUC/MIC = 3000) were over 90% for MIC ≤ 0.008 mg/L in any regimen. However, for MIC inferior to 0.016 mg/L, only loading dosage regimens provided PTAs exceeding 90%. For C. parapsilosis (AUC/MIC = 285), the maximum MIC of achieving a PTA ≥ 90% was 0.25 mg/L both in the regimens of B (150 mg maintenance dose) and C (200 mg maintenance dose) with loading dose. In addition, CFR of any regimen with loading dose was ≥ 90% against C. albicans and C. glabrata. None of the dosage regimens achieved an expected CFR against C. parapsilosis.

CONCLUSIONS

The dosage regimen of micafungin which had a loading dose of 1.5 times was more suitable for ICU patients infected by Candida spp.

An optimised dosing regimen versus a standard dosing regimen of vancomycin for the treatment of late onset sepsis due to Gram-positive microorganisms in neonates and infants aged less than 90 days (NeoVanc): study protocol for a randomised controlled trial

BACKGROUND

Vancomycin has been used in clinical practice for over 50 years; however, validated, pharmacokinetic (PK) data relating clinical outcomes to different dosing regimens in neonates are lacking. Coagulase negative staphylococci (CoNS) are the most commonly isolated organisms in neonatal, late-onset sepsis (LOS). Optimised use to maximise efficacy while minimising toxicity and resistance selection is imperative to ensure vancomycin's continued efficacy.

METHODS

NeoVanc is a European, open-label, Phase IIb, randomised, controlled, non-inferiority trial comparing an optimised vancomycin regimen to a standard vancomycin regimen when treating LOS known/suspected to be caused by Gram-positive organisms (excluding Staphylococcus aureus) in infants aged ≤ 90 days. Three hundred infants will be recruited and randomised in a 1:1 ratio. Infants can be recruited if they have culture confirmed (a positive culture from a normally sterile site and at least one clinical/laboratory criterion) or clinical sepsis (presence of any ≥ 3 clinical/laboratory criteria) in the 24 h before randomisation. The optimised regimen consists of a vancomycin loading dose (25 mg/kg) followed by 5 ± 1 days of 15 mg/kg q12h or q8h, dependent on postmenstrual age (PMA). The standard regimen is a 10 ± 2 day vancomycin course at 15 mg/kg q24h, q12h or q8h, dependent on PMA. The primary endpoint is a successful outcome at the test of cure visit (10 ± 1 days after the end of vancomycin therapy). A successful outcome consists of the patient being alive, having successfully completed study vancomycin therapy and having not had a clinical/microbiological relapse/new infection requiring treatment with vancomycin or other anti-staphylococcal antibiotic for > 24 h. Secondary endpoints include clinical/microbiological relapse/new infection at the short-term follow-up visit (30 ± 5 days after the initiation of vancomycin), evaluation of safety (renal/hearing), vancomycin PK and assessment of a host biomarker panel over the course of vancomycin therapy.

DISCUSSION

Based on previous pre-clinical data and a large meta-analysis of neonatal, PK/pharmacodynamic data, NeoVanc was set up to provide evidence on whether a loading dose followed by a short vancomycin course is non-inferior, regarding efficacy, when compared to a standard, longer course. If non-inferiority is demonstrated, this would support adoption of the optimised regimen as a way of safely reducing vancomycin exposure when treating neonatal, Gram-positive LOS.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02790996. Registered on 7 April 2016. EudraCT, 2015-000203-89. Entered on 18 July 2016.

Variability of voriconazole concentrations in patients with hematopoietic stem cell transplantation and hematological malignancies: influence of loading dose, procalcitonin, and pregnane X receptor polymorphisms

AIMS

Voriconazole (VCZ) displays highly variable pharmacokinetics affecting treatment efficacy and safety. We aimed to identify the factors affecting VCZ steady-state trough concentration (Cssmin) to provide evidence for optimizing VCZ treatment regimens.

METHODS

A total of 510 Cssmin of 172 patients with hematopoietic stem cell transplantation and hematologic malignancies and their clinical characteristics and genotypes of FMO, POR, and PXR were included in this study.

RESULTS

In univariate analysis, the standard loading dose of VCZ significantly increased the Cssmin of VCZ (P < 0.001). The Cssmin of VCZ was significantly correlated with patients' total bilirubin (TB) (P < 0.001) and procalcitonin (PCT) (P < 0.001). FMO3 rs2266780 (P = 0.025), POR rs10954732 (P = 0.015), PXR rs2461817 (P = 0.010), PXR rs7643645 (P = 0.003), PXR rs3732359 (P = 0.014), PXR rs3814057 (P = 0.005), and PXR rs6785049 (P = 0.013) have a significant effect on Cssmin of VCZ. Loading dose, TB, PCT level, and PXRrs3814057 polymorphism were independent influencing factors of VCZ Cssmin in the analysis of multivariate linear regression. And loading dose, PCT, and PXR rs3814057 had significant effects on the probability of the therapeutic window of VCZ.

CONCLUSION

The high variability of VCZ Cssmin may be partially explained by loading dose, liver function, inflammation, and PXR polymorphisms. This study suggests the VCZ standard loading dose regimen significantly increased Cssmin and probability of the therapeutic window providing treatment benefits. Patients in the high PCT group may be more likely to exceed 5.5 μg/mL, thus suffering from VCZ toxicity.

[Status of the clopidogrel use in ACS patients and related factors among county hospitals in China]

Objective: To observe the use of clopidogrel and related factors for patients with acute coronary syndrome (ACS) in terms of early use, loading dose, dual antiplatelet therapy (DAPT) and maintenance dose hospitalized in non-PCI country hospitals in China. Methods: Patients hospitalized for ACS from 101 non-PCI country hospitals across China were recruited prospectively from October 2011 to November 2014. In-hospital clopidogrel use rate, the proportions of early use (within 24 hours), loading dose use (≥300 mg), DAPT (early use combined with aspirin) and maintenance dose use (following dose≥75 mg/d) were analyzed. Generalized estimated equation (GEE) model was used to explore factors associated to in-hospital clopidogrel use and loading dose use in both univariate and multivariate analyses, adjusting for cluster effect. Results: A total of 14 809 ACS patients were included, with an average age of (64.1±11.6) years and 60% (8 888/14 809) were male. The in-hospital clopidogrel use rate was 66.4% (9 828/14 809), which varied across different regions, years and sub-types of ACS (all P<0.05). Among users, the proportions of patients with early use, DAPT and maintenance dose use were 91.3% (8 734/9 562), 89.2% (8 526/9 562) and 95.1% (9 094/9 562), respectively, but the proportion of patients received loading dose was only 41.8% (3 995/9 562). Multivariate analyses showed that patients who admitted to hospital in earlier years and with non-ST elevation ACS, ≥75 years old, female, non-smoking, illiterate, heart rate≥100 beats per minute, atrial fibrillation, not on ECG monitoring, and not using other anti-ACS drugs were less likely to receive clopidogrel (all P<0.05). And those clopidogrel users who with non-ST elevation ACS, ≥75 years old, non-smoking, illiterate, not using other anti-ACS drugs were less likely to receive loading dose (all P<0.05). Conclusion: The use rate of clopidogrel and the loading dose among in-hospital ACS patients are both low and remain to be improved in non-PCI county hospitals in China. Special attention should be paid on non-ST elevation ACS, ≥75 years old, female, and illiterate patients to increase the rational use of clopidogrel and the loading dose.

Relationship Status between Vancomycin Loading Dose and Treatment Failure in Patients with MRSA Bacteremia: It's Complicated

INTRODUCTION

A one-time vancomycin loading dose of 25-30 mg/kg is recommended in the current iteration of the vancomycin consensus guidelines in order to more rapidly achieve target serum concentrations and hasten clinical improvement. However, there are few clinical data to support this practice, and the extents of its benefits are largely unknown.

METHODS

A multicenter, retrospective, cohort study was performed to assess the impact of a vancomycin loading dose (≥ 20 mg/kg) on clinical outcomes and rates of nephrotoxicity in patients with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia. The study matched patients in a 1:1 fashion based on age, Pitt bacteremia score, and bacteremia source. The primary outcome was composite treatment failure (30-day mortality, bacteremia duration ≥ 7 days after vancomycin initiation, persistent signs and symptoms of infection ≥ 7 days after vancomycin initiation, or switch to an alternative antimicrobial agent). Secondary outcomes included duration of bacteremia, length of stay post-bacteremia onset, and nephrotoxicity.

RESULTS

A total of 316 patients with MRSA bacteremia were included. Median first doses in the loading dose and non-loading dose groups were 23.0 mg/kg and 14.3 mg/kg, respectively (P < 0.001). No difference was found in composite failure rates between the non-loading dose and loading dose groups (40.5% vs. 36.7%; P = 0.488) or in the incidence of nephrotoxicity (12.7% vs. 16.5%; P = 0.347). While multivariable regression modeling showed receipt of a vancomycin loading dose on a mg/kg basis was not significantly associated with composite failure [aOR 0.612, 95% CI (0.368-1.019)]; post hoc analyses demonstrated that initial doses ≥ 1750 mg were independently protective against failure [aOR 0.506, 95% CI (0.284-0.902)] without increasing the risk for nephrotoxicity [aOR 0.909, 95% CI (0.432-1.911)].

CONCLUSION

These findings suggest that initial vancomycin doses above a certain threshold may decrease clinical failures without increasing toxicity and that weight-based dosing might not be the optimal strategy.

Determination of optimal loading and maintenance doses for continuous infusion of vancomycin in critically ill patients: Population pharmacokinetic modelling and simulations for improved dosing schemes

OBJECTIVES

Despite extensive clinical use, limited data are available on optimal loading and maintenance doses of vancomycin in critically ill patients. This study aimed to develop a rational approach for optimised dosage of vancomycin given in a continuous infusion in critically ill patients.

METHODS

Vancomycin pharmacokinetic (PK) data (total serum concentrations) were obtained from 55 intensive care unit (ICU) patients (Bach Mai Hospital, Hanoi, Vietnam) receiving a 20 mg/kg loading dose followed by continuous infusion stratified by creatinine clearance (CLCr). Population PK modelling and Monte Carlo simulations were performed using a nonlinear mixed-effects modelling (NONMEM) program for a target of 20-30 mg/L to optimise efficacy and minimise nephrotoxicity.

RESULTS

A two-compartment model with first-order elimination best fitted the PK data with central and peripheral volumes of distribution of 1.01 and 2.39 L/kg, respectively (allometric scaling to a 70 kg standard subject). The population total clearance of 3.63 L/h was only explained by renal function in the covariate and final model. The simulations showed that a 25-mg/kg loading dose infused over 90 minutes was optimal to reach the target range. The optimal maintenance dose for low renal function (CLCr < 45 mL/min) was 1000-1500 mg/day. For augmented renal clearance (CLCr > 130 mL/min) the dose should be up to 3500 mg/day or even 4500 mg/day to achieve adequate exposure. These simulated maintenance doses were larger than previously proposed for non-ICU patients.

CONCLUSION

Large loading and maintenance doses of vancomycin are generally needed in critically ill patients. Because of high interindividual variability in vancomycin PK, drug monitoring may still be necessary.

Retrospective study on clinical efficacy and safety for daptomycin intermittent doses with or without loading dose in renal failure patients

This retrospective study is to evaluate the efficacy and safety of daptomycin (DAP) intermittent doses and the effectiveness of DAP loading dose in renal failure patients received DAP intermittent doses. One hundred and ninety-seven patients received DAP for at least 3 days from 2014 to 2017. Clinical and microbiological outcomes and the safety were assessed. A total of 183 patients (93, 60 and 30 patients received DAP daily dose, every 48 h dose and thrice per week dose) were included. DAP intermittent doses, such as every 48 h dose (28.3%) and thrice per week dose (30.0%), showed significantly higher mortality rates than that of DAP daily dose (6.5%) (p = 0.0320). Especially for bacteremia patients, significantly higher mortality was admitted, compared with patients received DAP daily doses (p = 0.0160). Moreover, patients received DAP intermittent doses were admitted slower improvements of their inflammation after DAP therapy started, compared with patients received daily dose. Additionally, DAP loading dose for renal failure patients decreased their mortality and improved patients' inflammation early. Especially for patients received DAP thrice per week dose, they showed significantly lower mortality than patients received non-loading dose (p = 0.0306). Additionally, these clinical enhancements of DAP therapy with loading dose were admitted without any enhancements of its adverse effect risks, except alkaline phosphatase elevation, compared with non-loading dose. In conclusion, DAP intermittent doses showed poor clinical outcomes, compared with daily dose. Then, DAP loading dose would be better clinical option for patients received DAP intermittent doses.

Evaluating the optimal dose of teicoplanin with therapeutic drug monitoring: not too high for adverse event, not too low for treatment efficacy

Therapeutic drug monitoring (TDM) of teicoplanin is aimed at minimizing the clinical impact of pharmacokinetic variability; however, its benefits are still being defined. We performed a retrospective study of teicoplanin TDM focusing on the dose-serum concentration relationship and clinical outcomes in a clinical setting. From January 2017 to December 2018, patients receiving teicoplanin ≥ 72 h with TDM were enrolled. Patients were divided into three groups: non-loading (NL) group, low-dose loading (LD) group (loading dose < 9 mg/kg), and high-dose loading (HD) group (≥ 9 mg/kg). Serum teicoplanin trough concentration (C_min) and adverse events (AEs) were evaluated in each regimen. A subgroup of patients with bacteremia was analyzed to evaluate clinical efficacy. Among 65 patients, 12, 18, and 35 were grouped in NL, LD, and HD, respectively. Achievement rates of C_min > 20 mg/L within 10 days were significantly different among the groups (25.0%, 38.9%, and 68.6% in the NL, LD, and HD groups, respectively; P = 0.014). Fourteen patients (21.5%) had AEs, and higher C_min over 10 days (adjusted odds ratio 2.08 per every 20 mg/L increases, 95% CI 1.13-3.84, P = 0.019) and age ≥ 65 years (P = 0.009) were identified as independent risk factors. In the subgroup analysis, HD regimen (P = 0.050) and high mean C_min over 10 days (P = 0.025) were significantly associated with treatment success. Although HL regimen could achieve C_min targets and improve clinical outcome during teicoplanin treatment, high C_min was associated with AEs during treatment. Routine TDM can be helpful to optimize teicoplanin administration.

Comparison of lower loading dose of prasugrel with conventional loading dose of prasugrel in Indian patients undergoing percutaneous coronary interventions

Background

Although conventional 60 mg of prasugrel allows for rapid and potent platelet inhibition within 30 min after loading dose, the efficacy and safety of lower doses of prasugrel in Indian patients has not yet been investigated.

Objective

The study sought to compare the efficacy of a lower loading dose of prasugrel with conventional loading dose of prasugrel in Indian patients.

Material and methods

Three hundred thirty-two Indian patients undergoing elective percutaneous coronary intervention (PCI) were enrolled in the study. Participants were randomly administered loading doses of prasugrel 60 mg (group A, n = 166) or 30 mg (group B, n = 166) before undergoing elective PCI in a 1:1 manner. Primary efficacy end point was composite of in-hospital death and stent thrombosis at 96 h, while safety end point was in-hospital bleeding.

Results

The two groups did not differ in their baseline characteristics. The primary efficacy end point was 0.6% in both the conventional 60 mg loading dose (LD) and lower 30 mg LD groups (p = not significant). Minor bleeding was significantly less in group B [Bleeding Academic Research Consortium 1, A = 6.63% vs B = 1.81%, odds ratio (OR) = 3.86, 95% confidence interval (CI) = 1.06–14.08, P = 0.05]. Major bleeding was higher in group A (A = 3.61%, vs B = 1.81%, OR = 2.04, 95% CI = 0.50–8.29, P = 0.50).

Conclusion

In Indian patients, 30 mg of prasugrel loading is as effective as 60 mg of prasugrel with significantly less minor bleeding.

Intravenous lacosamide (LCM) in status epilepticus (SE): Weight-adjusted dose and efficacy

BACKGROUND

Some studies suggest higher efficacy of lacosamide (LCM) in status epilepticus (SE) with higher loading doses; however, this weight-adjusted dose has not been evaluated.

OBJECTIVE

The objective was to evaluate the relationship between loading weight-adjusted dose and efficacy of LCM in SE.

METHODS

A group of patients with SE treated with LCM from Spanish hospitals was examined retrospectively. Demographic data, type of SE, etiology, response rate, last antiepileptic drug (AED) used, treatment line in which LCM was used, total loading dose, and weight-adjusted dose were collected.

RESULTS

One hundred sixty-five cases of SE were collected; 87 (52.7%) patients had nonconvulsive SE. Mean age was 64.2 ± 17.2 and 60.6% (n = 100) were men. Regarding etiology, SE was considered as acute symptomatic in 85 (51.5%), remote symptomatic in 51 (30.9%), progressive symptomatic in 10 (6.1%), and cryptogenic in 19 (11.5%). Lacosamide was used as the third drug in 46.1%, and as a second option in 28%. In 115 patients, clonazepam had been used as the first option, and no benzodiazepines had been administered in the remaining 50. The median loading dose was 400 mg (100-600 mg), and the weight-adjusted dose was 5 mg/kg (3-6 mg/kg). The response rate was 63.3%, and 55.1% responded within the first 12 h. Efficacy was significantly higher in patients who had taken benzodiazepines at LCM loading doses >5.3 mg/kg (p = 0.006). This relationship was maintained independent of using other concomitant AEDs. However, if benzodiazepines were not taken, this relationship was not found.

CONCLUSIONS

In adults with benzodiazepine-resistant SE, the response rate to LCM was higher, with weight-adjusted doses above 5.3 mg/kg.

Effects of an Unlabeled Loading Dose on Tumor-Specific Uptake of a Fluorescently Labeled Antibody for Optical Surgical Navigation

PURPOSE

Intraoperative optical imaging to guide surgeons during oncologic resections offers a unique and promising solution to the ambiguity of cancer margins to tactile and visual assessment that results in devastatingly high rates of positive margins. Sequestering of labeled antibodies by normal tissues with high expression of the antibody target, or "antigen sinks", diminishes the efficacy of these probes to provide contrast between the tumor and background tissues by decreasing the amount of circulating probe available for uptake by the tumor and by increasing the fluorescence of non-tumor tissues. We hypothesized that administering a dose of unlabeled antibody prior to infusion of the near-infrared (NIR) fluorescently labeled antibody would improve tumor-specific uptake and contrast of the fluorescently labeled probe by occupying extra-tumoral binding sites, thereby increasing the amount of labeled probe available for uptake by the tumor.

PROCEDURES

In this study, we explore this concept by testing two different "pre-load" doses of unlabeled cetuximab (the standard 10-mg test dose, and a larger, experimental 100-mg test dose) in six patients receiving cetuximab conjugated to the fluorescent dye IRDye800CW (cetuximab-IRDye800CW) in a clinical trial, and compared the amount of fluorescent antibody in tumor and background tissues, as well as the tumor-specific contrast of each.

RESULTS

The patients receiving the larger preload (100 mg) of unlabeled cetuximab demonstrated significantly higher concentrations (9.5 vs. 0.1 μg) and a longer half-life (30.3 vs. 20.6 days) of the labeled cetuximab in plasma, as well as significantly greater tumor fluorescence (32.3 vs. 9.3 relative fluorescence units) and tumor to background ratios (TBRs) (5.5 vs. 1.7).

CONCLUSIONS

Administering a preload of unlabeled antibody prior to infusion of the fluorescently labeled drug may be a simple and effective way to improve the performance of antibody-based probes to guide surgical resection of solid malignancies.

Modified Colistin Regimen for Critically Ill Patients with Acute Renal Impairment and Continuous Renal Replacement Therapy

Colistin is a last resort antibiotic to treat multidrug-resistant Gram-negative bacteria infections. Colistin is administered intravenously in the form of its inactive prodrug colistin methanesulfonate (CMS). For patients with acute kidney impairment and continuous renal replacement therapy high extracorporeal clearance may cause a substantial removal of active colistin from the bloodstream, eventually decreasing its antibacterial efficacy. Currently recommended doses of CMS may therefore be inadequate for these patients. We report on the potential value of a modified regimen that adopts a loading dose of CMS (bolus of 9 MU vs. conventional 3 MU every 8 h), followed by maintenance (3 MU every 8 h). Preliminary pharmacokinetic evidence for the feasibility and efficacy of this regimen is described for 2 patients.

Optimal Trough Concentration of Teicoplanin in Febrile Neutropenic Patients with Hematological Malignancy

BACKGROUND

Teicoplanin is a glycopeptide antibiotic currently used for the treatment of methicillin-resistant Staphylococcus aureus. The need for therapeutic drug monitoring of teicoplanin has been increasingly highlighted as important. It is generally accepted that whereas a plasma trough concentration (Cmin) of ≥10 mg/L is appropriate for the majority of infections, it should exceed 20 mg/L for severe infections. The target Cmin of teicoplanin in patients with febrile neutropenia (FN) has not been reported. The aim of this study was to estimate the target Cmin for the treatment of FN in patients with hematological malignancy.

METHODS

In this retrospective, single-center, observational cohort study, the records of 52 hospitalized patients with hematological malignancy who were treated with teicoplanin for FN due to bacteriologically documented or presumptive gram-positive infections were analyzed.

RESULTS

A significant difference in the first Cmin of teicoplanin was observed between the response and nonresponse groups in patients with bacteremia. The areas under the receiver operating characteristic curves were 0.80 for clinical efficacy. The cut-off value of teicoplanin Cmin on days 4-6 was 15.2 mg/L (sensitivity 80.0%, specificity 75.0%).

CONCLUSIONS

The authors propose a target teicoplanin Cmin of ≥15.2 mg/L for FN in patients with hematological malignancy.

Colistin loading dose enhanced antimicrobial activity for in vivo mouse thigh infection model with Pseudomonas aeruginosa with highly antimicrobial resistant

This is the first report to test the loading dosage of colistin against Pseudomonas aeruginosa, including MDRP. Using in vivo murine thigh infection model, in the loading dosage regimen (Day 1:50 mg/kg q12 h, Day 2-3: 25 mg/kg q12 h) group, 5 to 6 log10 CFU/ml reduction compared with control were observed for both strains of P. aeruginosa with colistin MIC 0.5 and 1 μg/mL at 72 h. But, similar reduction was observed for the strains with colistin MIC 0.5 μg/mL only in normal dosage regimen (Day 1-3: 25 mg/kg q12 h) group. For P. aeruginosa with colistin MIC 1 μg/mL, colistin loading dosage regimens showed greater antimicrobial activity than that of without loading dosage group (p < 0.05). These data suggest that the colistin loading regimen would be one of the useful options for P. aeruginosa with antimicrobial resistance infection treatment.

Challenge for higher colistin dosage in critically ill patients receiving continuous venovenous haemodiafiltration

Traditionally, reduced daily doses of colistin methanesulphonate (CMS) in critically ill patients receiving continuous venovenous haemodiafiltration (CVVHDF) have resulted in suboptimal colistin concentrations. The necessity of a loading dose (LD) at treatment initiation has been proposed. A LD of 9 million IU (MU) [ca. 270 mg of colistin base activity (CBA)] was administrated with a maintenance dose of 4.5 MU (ca. 140 mg CBA) every 12 h (q12h) to eight critically ill patients receiving renal replacement therapy. Blood samples were collected immediately before and at different time intervals after the LD and the fourth dose, whilst pre-filter and post-filter blood samples were also collected. CMS and colistin concentrations were determined using an LC-MS/MS assay. Median maximum observed concentrations after the LD were 22.1 mg/L for CMS and 1.55 mg/L for colistin, whereas during maintenance dosing the corresponding values were 12.6 mg/L and 1.72 mg/L, respectively. CVVHDF clearance was determined as 2.98 L/h for colistin, equivalent to 62% of total apparent colistin clearance in CVVHDF patients. Both CMS and colistin were cleared by CVVHDF. Application of a LD of 9 MU CMS resulted in more rapid achievement of the target colistin concentration. Following implementation of a predicted pharmacokinetic model on plasma CMS/colistin concentrations, a LD of 12 MU CMS appears more appropriate, whilst a CMS maintenance dosage of at least 6.5-7.5 MU q12h is suggested in patients undergoing CVVHDF. However, further clinical studies are warranted to assess the safety of a LD of 12 MU CMS in patients receiving CVVHDF.

Initiation of intravitreal aflibercept injection treatment in patients with diabetic macular edema: a review of VIVID-DME and VISTA-DME data

Background

Diabetic macular edema (DME) shows a gradual and sustained functional and morphologic response to anti-vascular endothelial growth factor (VEGF) drugs, but the optimal schedule for initiation of anti-VEGF therapy is not known. This study evaluates the treatment response behavior of DME in the Phase 3 trials of intravitreal aflibercept, with 5 initial intravitreal aflibercept injections (IAI), 2 mg every 4 weeks (2q4), in the upload phase.

Methods

This post hoc pooled analysis of the VISTA-DME (NCT01363440) and VIVID-DME (NCT01331681) trials evaluated the change in best-corrected visual acuity (BCVA) and central retinal thickness (CRT) during the upload phase, using pooled data from both IAI treatment groups [2q4 and 2 mg every 8 weeks (2q8)]. The mean visit-to-visit change in BCVA and CRT, and the respective rate of gainers and losers was calculated for each successive visit. A secondary analysis compared the visit-to-visit change in BCVA between the 2q4 and 2q8 treatment arms during the upload period and the first year treatment period.

Results

The majority of eyes showed a continuing improvement of BCVA after the first IAI. The proportions of eyes gaining BCVA (≥5 letters) at each visit compared with the previous visit during the IAI 2q4 upload phase were 60 (4-weeks), 19 (8-weeks), 16 (12-weeks), 15 (16-weeks), and 14 % (20-weeks). In contrast, the proportions of eyes losing BCVA (≥5 letters) were 3 (4-weeks), 7 (8-weeks), 7 (12-weeks), 9 (16-weeks), and 8 % (20-weeks), respectively. The odds of BCVA (≥5 letters) gain/loss exceeded 1.7 at each visit (range 1.7–20). Overall, the proportion of patients with BCVA gain ≥5 letters at week 20 (compared with baseline) was 76 and 80 % in the 2q4 and 2q8 groups, respectively. The proportions of eyes showing a visit-to-visit decrease in CRT of ≥30 µm during the first 5 IAI were 77 (4-weeks), 27 (8-weeks), 21 (12-weeks), 17 (16-weeks), and 12 % (20-weeks). In the secondary analysis, the BCVA outcomes were similar for the 2q8 and 2q4 treatment arms.

Conclusions

The data presented here are consistent with continual functional and anatomic improvement following the fourth and fifth initial 2q4 injections, suggesting that an intensive and sufficiently long upload may be beneficial.

Trial registration VIVID-DME: Clinicaltrials.gov: NCT01331681; VISTA-DME: Clinicaltrials.gov: NCT01363440

Platelet reactivity in patients receiving a maintenance dose of P2Y12-ADP receptor antagonists undergoing elective percutaneous coronary intervention

BACKGROUND

P2Y12-ADP receptor blockade during percutaneous coronary intervention (PCI) is critical to prevent thrombotic events. In patients under chronic P2Y12 blockers, the use of additional loading dose (LD) before an elective PCI is debated. We aimed to investigate the rate of high on-treatment platelet reactivity (HTPR) in patients undergoing elective PCI during chronic clopidogrel or ticagrelor therapy.

METHODS AND RESULTS

We performed a sub-group analysis of a randomized trial comparing ticagrelor and clopidogrel in acute coronary syndrome (ACS) patients undergoing PCI. Multi-vessel disease patients requiring a staged PCI one month after the ACS were included. The VASP (vasodilatatory phosphoprotein) index, which is a specific and reproducible platelet assay to measure P2Y12-ADP receptor activity, was used to assess the biological efficacy of the maintenance dose (MD) of ticagrelor and clopidogrel before PCI. Forty-one patients in each group of randomization required a staged PCI. They were similar regarding the baseline demographic, clinical and angiographic characteristics. The mean VASP index in the ticagrelor group was 20.7±8.8% compared to 51.8±17% in the clopidogrel group (p<0.001) before PCI. No patients had a VASP index ≥50% in the ticagrelor group compared to 56% in the clopidogrel group (p<0.001). Following PCI the rate of peri-procedural MI was higher in the clopidogrel group (p=0.02).

CONCLUSIONS

Unlike clopidogrel MD, ticagrelor MD achieves an optimal PR inhibition in all patients during a staged PCI.

Post-hoc analysis showing better clinical response with the loading dose of certolizumab pegol in Japanese patients with active rheumatoid arthritis

Objectives: To compare the efficacy and safety of certolizumab pegol (CZP) with and without loading dose (LD) in a post-hoc analysis of two Japanese clinical studies.

Methods: Data from the double-blind trials (DBT) J-RAPID and HIKARI, and their open-label extension (OLE) studies, were used. Patients randomized to CZP 200 mg every 2 weeks (Q2W) groups starting with LD (400 mg Weeks 0/2/4; LD group; J-RAPID: n = 82, HIKARI: n = 116) and patients randomized to placebo groups who subsequently started CZP Q2W without LD in the OLEs (No-LD group; J-RAPID: n = 61, HIKARI: n = 99) were analyzed. Efficacy and pharmacokinetics were assessed during 24 weeks. Adverse events were reported from all studies.

Results: In both trials, the LD groups showed more rapid initial ACR20/50/70 kinetics, and maintained higher ACR50/70 responses until 24 weeks, compared with the No-LD groups. Anti-CZP antibody development was less frequent in the LD groups (J-RAPID: 1.2% versus 4.9%; HIKARI: 17.2% versus 27.3%). Similar safety profiles were reported between LD and No-LD groups (any AEs: 281.8 versus 315.7 [J-RAPID], 282.6 versus 321.3 [HIKARI] [incidence rate/100 patient-years]).

Conclusions: Despite limitations, including comparing DBT and OLE studies, these results suggest that a CZP LD improves clinical response in active rheumatoid arthritis without altering the safety profile.

Inadvertent overinfusion of norepinephrine using infusion pump loading dose

Programming infusion pumps has been recognised as a high-risk step and a source of adverse events (Nuckols et al., 2008; Hyman, 2010). Literature describing infusion pump loading dose errors and NORepinephrine complications is scarce (Girard et al., 2010). This case study presents the first ever report of an inadvertent overinfusion of NORepinephrine due to the loading dose option on the infusion pump, and resulting cardiac arrest of the patient. A patient was admitted to the emergency room and started on a NORepinephrine infusion inadvertently as a loading dose rather than a primary infusion. Historical values for the loading dose volume to be infused (VTBI) and primary rate were not adjusted during the setup. Eight hours and 58minutes later, the loading dose VTBI reached 0mL and the pump reverted to the historical primary rate of 999mL/hour. The event log showed that 37.1mL of NORepinephrine was infused resulting in an equivalent calculated bolus dose of 1.8mg administered in two minutes. The patient suffered a cardiac arrest and the infusion was stopped. No faults were found with the pump. Herein, we discuss our analysis of the pump event logs and propose further safety strategies and interventions.

Safety & pK of IV loading dose of lacosamide in the ICU

A restrospective review of patients treated in the ICU for refractory status epilepticus who had received an initial IV loading dose of lacosamide (LCS) was performed. A total of 142 patients were identified. The first 34 patients received 400mg which by weight-based measurement ranged from 2 to 11 mg/kg. Higher mg/kg dosing had been used subsequently with doses up to 13 mg/kg. No patient required reduction in rate or cessation of infusion. Initiation of pressor agents was not needed during the infusion of the loading dose. Postinfusion LCS blood levels were drawn, and dosing of 10-12 mg/kg and higher resulted in blood levels above 15 μg/ml while doses of 2-6 mg/kg resulted in levels below 10 μg/ml. We conclude that a weight-based loading dose of 10-12 mg/kg at an infusion rate of 0.4 mg/kg/min is safe and will produce levels of 15 μg/ml and higher. This article is part of a Special Issue entitled "Status Epilepticus".

Enhancing Patient Flexibility of Subcutaneous Immunoglobulin G Dosing: Pharmacokinetic Outcomes of Various Maintenance and Loading Regimens in the Treatment of Primary Immunodeficiency

Introduction

Standard treatment for patients with primary immunodeficiency (PID) is monthly intravenous immunoglobulin (IVIG), or weekly/biweekly subcutaneous immunoglobulin (SCIG) infusion. We used population pharmacokinetic modeling to predict immunoglobulin G (IgG) exposure following a broad range of SCIG dosing regimens for initiation and maintenance therapy in patients with PID.

Methods

Simulations of SCIG dosing were performed to predict IgG concentration–time profiles and exposure metrics [steady-state area under the IgG concentration–time curve (AUC), IgG peak concentration (C_max), and IgG trough concentration (C_min) ratios] for various infusion regimens.

Results

The equivalent of a weekly SCIG maintenance dose administered one, two, three, five, or seven times per week, or biweekly produced overlapping steady-state concentration–time profiles and similar AUC, C_max, and C_min values [95% confidence interval (CI) for ratios was 0.98–1.03, 0.95–1.09, and 0.92–1.08, respectively]. Administration every 3 or 4 weeks resulted in higher peaks and lower troughs; the 95% CI of the AUC, C_max, and C_min ratios was 0.97–1.04, 1.07–1.26, and 0.86–0.95, respectively. IgG levels >7 g/L were reached within 1 week using a loading dose regimen in which the weekly maintenance dose was administered five times in the first week of treatment. In patients with very low endogenous IgG levels, administering 1.5 times the weekly maintenance dose five times in the first week of treatment resulted in a similar response.

Conclusions

The same total weekly SCIG dose can be administered at different intervals, from daily to biweekly, with minimal impact on serum IgG levels. Several SCIG loading regimens rapidly achieve adequate serum IgG levels in treatment-naïve patients.

Electronic supplementary material

The online version of this article (doi:10.1007/s13554-014-0018-0) contains supplementary material, which is available to authorized users.

Therapeutic drug concentrations of teicoplanin in clinical settings

Background

Teicoplanin is a glycopeptide antibiotic that is widely used in clinical practice for the treatment of infections caused by drug-resistant Gram-positive bacteria. The aim of this study was to analyze plasma teicoplanin concentrations to determine the percentage of patients in whom therapeutic concentrations of teicoplanin were achieved in clinical practice.

Materials and Methods

The plasma teicoplanin concentrations of hospitalized patients receiving treatment at a teaching hospital were retrospectively analyzed. The target level was defined as a plasma teicoplanin concentration of 10 mg/L or greater, since this was generally regarded as the lower limit of the optimal concentration range required for the effective treatment of a majority of infections.

Results

Patients with sub-optimal (< 10 mg/L) plasma teicoplanin concentrations constituted nearly half of the total study population. The majority of these patients received the recommended loading dose, which were three 400 mg doses administered every 12 hours. Sub-group analysis showed a trend that the group receiving loading dose was more likely to reach the optimal teicoplanin concentration.

Conclusions

The data revealed that a significant proportion of patients in clinical practice achieved only sub-optimal teicoplanin concentrations, which emphasizes the importance of the mandatory use of loading dose and routine therapeutic drug monitoring. Treatment reassessment and simulation of individual dose regimens may also be necessary to achieve optimal drug concentrations.

A phase II/III, multicenter, safety, efficacy, and pharmacokinetic study of dexmedetomidine in preterm and term neonates

OBJECTIVE

To investigate the safety, efficacy, and pharmacokinetic profile of dexmedetomidine in preterm and full-term neonates ≥ 28 to ≤ 44 weeks gestational age.

STUDY DESIGN

Forty-two intubated, mechanically ventilated patients (n = 42) were grouped by gestational age into group I (n = 18), ≥ 28 to <36 weeks, and group II (n = 24), ≥ 36 to ≤ 44 weeks. Within each age group, there were 3 escalating dose levels, including a loading dose (LD, μg/kg) followed by a maintenance dose (MD, μg · kg(-1) · h(-1)) for 6-24 hours: level 1, 0.05 LD/MD; level 2, 0.1 LD/MD; and level 3, 0.2 LD/MD. The primary endpoint was the number of patients requiring sedation as determined by the Neonatal Pain, Agitation, Sedation Scale.

RESULTS

During dexmedetomidine infusion, 5% of Neonatal Pain, Agitation, Sedation Scale scores were >3, indicating agitation/pain, with 4 patients (10%) requiring more sedation and 17 (40%) requiring more analgesia. Though there was significant variability in pharmacokinetic variables, group I appeared to have lower weight-adjusted plasma clearance (0.3 vs 0.9 L · h(-1) · kg(-1)) and increased elimination half-life (7.6 vs 3.2 hours) compared with group II. Fifty-six adverse events (AEs) were reported in 26 patients (62%); only 3 AEs (5%) were related to dexmedetomidine. There were no serious AEs and no AEs or hemodynamic changes requiring dexmedetomidine discontinuation.

CONCLUSION

Dexmedetomidine is effective for sedating preterm and full-term neonates and is well-tolerated without significant AEs. Preterm neonates had decreased plasma clearance and longer elimination half-life.

High-dose regimen to achieve novel target trough concentration in teicoplanin

In the treatment of severe MRSA infections such as endocarditis, more than 20 mg/L of plasma trough concentration (C(min)) is recommended for teicoplanin; however, in the treatment of common MRSA infections, recommended C(min) remains more than 10 mg/L. In this study, we set C(min) as 15-30 mg/L to obtain a favorable clinical outcome in the treatment of common MRSA infections, and investigated the optimal loading regimen that achieved the target C(min) in patients with normal renal function. Seventy-eight patients received the high-dose regimen A (6 mg/kg every 12-h for initial two days) and 60 patients received the high-dose regimen B (the first five loading doses of 10-12 mg/kg at 12-h intervals for initial three days, followed by 6 mg/kg once daily). The mean C(min) on the 4th day was 13.7 ± 5.3 mg/L in regimen A, and 20.0 ± 6.6 mg/L in regimen B (P < 0.001), and the proportion of patients achieving the 15-30 mg/L was 25.6% and 68.3% (P < 0.001). Clinical response at end-of treatment were 66.7% and 85.0% (P = 0.014). The patients of initial C(min) with ≥15 mg/L had tended to be higher clinical response than those with <15 mg/L (80.9% vs 68.6%, P = 0.084). There were no significant differences in the occurrence of adverse effects in regimen A and B (nephrotoxicity; 1.3% vs 3.3%, P = 0.413, hepatotoxicity; 5.1% vs 3.3%, P = 0.608). In conclusion, to obtain C(min) 15-30 mg/L, the first five loading doses of 10-12 mg/kg at 12-h intervals was required in patients with normal renal function.