An Open, Randomized, Single-Center, Crossover Pharmacokinetic Study of Meropenem after Intraperitoneal and Intravenous Administration in Patients Receiving Automated Peritoneal Dialysis

Population pharmacokinetics of meropenem in patients undergoing automated peritoneal dialysis

BACKGROUND

Meropenem is a second-line agent for the treatment of peritoneal dialysis-associated peritonitis (PD peritonitis), while information on pharmacokinetics (PK) of intraperitoneal (i.p.) meropenem is limited in this patient group. The objective of the present evaluation was to assess a pharmacokinetic rationale for the selection of meropenem doses in automated PD (APD) patients based on population PK modelling.

METHODS

Data were available from a PK study in six patients undergoing APD who received a single 500 mg dose of meropenem intravenous or i.p. A population PK model was developed for plasma and dialysate concentrations (n = 360) using Monolix. Monte Carlo simulations were carried out to assess the probability of achieving meropenem concentrations above minimum inhibitory concentrations (MICs) of 2 and 8 mg/L, representing susceptible and less susceptible pathogens respectively, for at least 40% of the dosing interval (T >MIC ≥ 40%).

RESULTS

A two-compartment model for each plasma and dialysate concentrations with one transit compartment for the transfer from plasma to dialysate fluid described the data well. An i.p. dose of 250 and 750 mg, for an MIC of 2 and 8 mg/L respectively, was sufficient to attain the pharmacokinetic/pharmacodynamic target (T >MIC ≥ 40%) in more than 90% patients in plasma and dialysate. Additionally, the model predicted that no relevant meropenem accumulation in plasma and/or peritoneal fluid would occur with prolonged treatment.

CONCLUSION

Our results suggest that an i.p. dose of 750 mg daily is optimal for pathogens with an MIC 2-8 mg/L in APD patients.

Azithromycin concentrations during long-term regimen, a pilot study in patients with MALT lymphoma

In view of the antineoplastic effects of the macrolide clarithromycin in mucosa associated lymphatic tissue (MALT)-lymphoma, we performed a pilot study assessing levels of azithromycin in plasma, peripheral blood mononuclear cells (PBMC) and polymorphonuclear leukocytes (PMN) of MALT-lymphoma patients to determine the pharmacokinetics and potential influences of respective concentrations on the therapeutic outcome. In total 16 patients with MALT-lymphoma received 1.5 g of oral azithromycin once-weekly over 6 months. Blood was sampled directly prior to the following dose every 4 weeks during treatment. Drug levels were analysed by high performance liquid chromatography in plasma and intracellularly in PBMC and PMN. They were correlated with patients’ age, weight and body-mass-index and compared between patients responsive or unresponsive to treatment. Mean azithromycin plasma levels of all patients were 58.97 ± 30.48 ng/ml, remaining stable throughout the treatment period. Correlation analysis of plasma azithromycin showed no significance. Intracellular PBMC concentrations were 6648 ± 8479 ng/ml, without any significant difference between responders and non-responders. Mean PMN levels were 39,274 ± 25,659 ng/ml and significantly higher in patients unresponsive to treatment (t = 2.858, p = 0.017). Our drug regime led to continuously high plasma and exceedingly high intracellular concentrations of azithromycin in PBMC and PMN. Age, weight or body-mass-index had no significant influence on plasma levels and thence should not be considered in dosage finding. High AZM levels in PBMC did not lead to a better treatment response, whereas enrichment in PMN suggested a poorer outcome. The threshold for immunomodulatory effects on lymphoma cells might not have been reached. Additionally, the finding of stable plasma and intracellular concentrations over months with high-dose azithromycin administered in intervals might also be important for the further design of azithromycin-based trials against MALT-lymphoma.

Trial registration: EudraCT 2016-001521-13, 14/06/2016.

Peritoneal Dialysis Guidelines 2019 Part 1 (Position paper of the Japanese Society for Dialysis Therapy)

Approximately 10 years have passed since the Peritoneal Dialysis Guidelines were formulated in 2009. Much evidence has been reported during the succeeding years, which were not taken into consideration in the previous guidelines, e.g., the next peritoneal dialysis PD trial of encapsulating peritoneal sclerosis (EPS) in Japan, the significance of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), the effects of icodextrin solution, new developments in peritoneal pathology, and a new international recommendation on a proposal for exit-site management. It is essential to incorporate these new developments into the new clinical practice guidelines. Meanwhile, the process of creating such guidelines has changed dramatically worldwide and differs from the process of creating what were “clinical practice guides.” For this revision, we not only conducted systematic reviews using global standard methods but also decided to adopt a two-part structure to create a reference tool, which could be used widely by the society’s members attending a variety of patients. Through a working group consensus, it was decided that Part 1 would present conventional descriptions and Part 2 would pose clinical questions (CQs) in a systematic review format. Thus, Part 1 vastly covers PD that would satisfy the requirements of the members of the Japanese Society for Dialysis Therapy (JSDT). This article is the duplicated publication from the Japanese version of the guidelines and has been reproduced with permission from the JSDT.

Pharmacokinetics of culture-directed antibiotics for the treatment of peritonitis in automated peritoneal dialysis: A systematic narrative review

The objectives of this study were to provide a summary of the pharmacokinetic data of some intraperitoneal (IP) antibiotics that could be used for both empirical and culture-directed therapy, as per the ISPD recommendations, and examine factors to consider when using IP antibiotics for the management of automated peritoneal dialysis (APD)-associated peritonitis. A literature search of PubMed, EMBASE, Scopus, MEDLINE and Google Scholar for articles published between 1998 and 2020 was conducted. To be eligible, articles had to describe the use of antibiotics via the IP route in adult patients ≥18 years old on APD in the context of pharmacokinetic studies or case reports/series. Articles describing the use of IP antibiotics that had been recently reviewed (cefazolin, vancomycin, gentamicin and ceftazidime) or administered for non-APD-associated peritonitis were excluded. A total of 1119 articles were identified, of which 983 abstracts were screened. Seventy-three full-text articles were assessed for eligibility. Eight records were included in the final study. Three reports had pharmacokinetic data in patients on APD without peritonitis. Each of cefepime 15 mg/kg IP, meropenem 0.5 g IP and fosfomycin 4 g IP given in single doses achieved drug plasma concentrations above the minimum inhibitory concentration for treating the susceptible organisms. The remaining five records were case series or reports in patients on APD with peritonitis. While pharmacokinetic data support intermittent cefepime 15 mg/kg IP daily, only meropenem 0.5 g IP and fosfomycin 4 g IP are likely to be effective if given in APD exchanges with dwell times of 15 h. Higher doses may be required in APD with shorter dwell times. Information on therapeutic efficacy was derived from case reports/series in individual patients and without therapeutic drug monitoring. Until more pharmacokinetic data are available on these antibiotics, it would be prudent to shift patients who develop peritonitis on APD to continuous ambulatory peritoneal dialysis, where pharmacokinetic information is more readily available.

Vancomycin in peritoneal dialysis: Clinical pharmacology considerations in therapy

Intraperitoneal vancomycin is the first-line therapy in the management of peritoneal dialysis (PD)-related peritonitis. However, due to the paucity of data, vancomycin dosing for peritonitis in patients on automated peritoneal dialysis (APD) is empiric and based on clinical experience rather than evidence. Studies in continuous ambulatory peritoneal dialysis (CAPD) patients have been used to provide guidelines for dosing and are often extrapolated for APD use, but it is unclear whether this is appropriate. This review summarizes the available pharmacokinetic data used to inform optimal dosing in patients on CAPD or APD. The determinants of vancomycin disposition and pharmacodynamic effects are critically summarized, knowledge gaps explored, and a vancomycin dosing algorithm in PD patients is proposed.

Antibiotic Dosing in Chronic Kidney Disease and End-Stage Renal Disease: A Focus on Contemporary Challenges

Infections are an important cause of morbidity and mortality among patients with chronic kidney disease. Therefore, appropriate antibiotic dosing is imperative to achieve positive patient outcomes while minimizing antibiotic dose-related toxicity. Accurately assessing renal function and determining the influence of renal replacement therapy on antibiotic clearance makes drug dosing in this patient population challenging. Furthermore, as technological advances in hemodialysis and peritoneal dialysis occur, research incorporating newer dialysis parameters to guide drug dosing may not be readily available. Currently, there are limited data to guide drug dosing in the setting of automated peritoneal dialysis, short daily hemodialysis, and nocturnal hemodialysis. Antibiotic-dosing recommendations should be carefully evaluated considering the accuracy of the renal function assessment, the similarity of the operating characteristics of the renal replacement therapy studied compared with those being used, and whether the dosing strategy takes advantage of the pharmacodynamic profile of the antibiotic under consideration. After implementing the antibiotic-dosing regimen, therapeutic drug monitoring should occur when possible along with careful monitoring for antibiotic efficacy and safety.

Pharmacokinetic evaluation of meropenem and vaborbactam for the treatment of urinary tract infection

INTRODUCTION

Meropenem/vaborbactam (M/V) represents the first carbapenem and β-lactamase inhibitor combination approved for treatment of complicated urinary tract infections (cUTIs), including pyelonephritis. Vaborbactam is a novel boronic acid, β-lactamase inhibitor with a high affinity for serine β-lactamases, including Klebsiella pneumoniae carbapenemase (KPC). This combination, Vabomere™, was approved in August 2017 by the United States Food and Drug Administration for the treatment of cUTIs in patients 18 years or older, including pyelonephritis, caused by the following susceptible microorganisms: Escherichia coli, K. pneumoniae, and Enterobacter cloacae species complex. Areas covered: Relevant literature regarding microbiology, pharmacokinetics, pharmacodynamics, and clinical trials evaluating efficacy, safety, and tolerability will be discussed. Expert opinion: Current treatment options for KPC-producing infections such as aminoglycosides, polymyxins, fosfomycin, and tigecycline are associated with concerns regarding efficacy, toxicities, optimal dosing, and/or development of resistance. Additionally, resistance to the new combination product of ceftazidime/avibactam has also emerged. Current clinical evidence supporting the use of M/V for KPC-producing infections is limited to an open-label, randomized, phase III study in a small number of patients with serious infections due to carbapenem-resistant Enterobacteriaceae. Although M/V is not approved for KPC-producing infections, we believe that M/V will become a preferred agent for KPC-producing Enterobacteriaceae infections.

Colonoscopy in automated peritoneal dialysis patients: value of prophylactic antibiotics: a prospective study on a single antibiotic

OBJECTIVE

To evaluate the need for prophylactic antibiotics in automated peritoneal dialysis (APD) patients undergoing flexible colonoscopy.

PATIENTS AND METHODS

A total of 93 patients on automated peritoneal dialysis (APD) undergoing diagnostic colonoscopy were enrolled in a prospective, randomized study. Patients were randomized into 2 age- and sex-matched groups; group A (46 patients) with intraperitoneal (IP) ceftazidime prior to colonoscopy and group B (47 patients) without prophylactic antibiotics. The relations between peritonitis and different parameters were analyzed.

RESULTS

Of all colonoscopies, 60.2% showed normal findings, 17.2% with colonic polyps at different sites, 12.9% with angiodysplastic-like lesions, 5.4% with colonic ulcer(s), 3.2% with diverticulae without diverticulitis and 1.1% had transverse colon stricture. Post-colonoscopy peritonitis was documented in 3 (6.5%) and 4 (8.5%) patients in groups A and B, respectively (p = 0.2742); the causative organisms were mainly gram negative bacteria. Polypectomy was not associated with increased peritonitis episodes. By multiple logistic regression analysis, diabetes mellitus was the only independent variable that entered into the best predictive equation over the development of post-colonoscopy peritonitis but not antibiotic use.

CONCLUSIONS

The relation between prophylactic antibiotic use prior to colonoscopy in APD patients and the risk of peritonitis was lacking. Only diabetes mellitus appears to be of significance. Polypectomy did not increase peritonitis episodes.