Effect of glucose concentration on the stability of daptomycin in peritoneal solutions

Intraperitoneal daptomycin dosing for peritonitis may be inadequate: a Monte Carlo simulation approach to optimize dosing and outcomes

A two-compartmental mathematical pharmacokinetic model with first-order elimination of patients receiving CAPD of 4 exchanges for 6 h with 2 L of dialysate used in each cycle was developed to predict daptomycin disposition in 120 h of therapy. The pharmacodynamic target was plasma AUC/MIC equal to or greater than 666. The dose that achieved at least 90% of the probability of target attainment was defined as an optimal dose. Administering intraperitoneal 300 mg daily for 1 exchange daily regimen would be sufficient to treat peritonitis with S. aureus infection with MICs of 0.25 mg/L in patients undergoing CAPD. A higher dosage may be required for infections with a higher minimum inhibitory concentration. Pharmacodynamic targets and MICs significantly contributed to daptomycin doses in this setting. Clinical validation of our recommendations is recommended.

Stability and compatibility of intraperitoneal antimicrobials in peritoneal dialysate solutions

To optimise antimicrobial administration in patients with peritoneal dialysis (PD)-related peritonitis, healthcare providers need literature-based information to develop patient-centred pharmacotherapeutic plans. Traditional PD solutions promote osmosis using dextrose or icodextrin with a lactate buffer. Newer PD solutions have modified the osmotic vehicle and buffer. Knowledge of antimicrobial compatibility and stability with newer PD solutions will assist with determining the route of antimicrobial administration as compatible and stable solutions could be delivered directly to the peritoneum using intraperitoneal administration. This review updates the compatibility and stability of antimicrobial additives in newer PD solutions for PD-related peritonitis.

Culture-directed antibiotics in peritoneal dialysis solutions: a systematic review focused on stability and compatibility

BACKGROUND

This systematic review summarises the stability of less commonly prescribed antibiotics in different peritoneal dialysis solutions that could be used for culture-directed therapy of peritonitis, which would be especially useful in regions with a high prevalence of multidrug antibiotic-resistant strains.

METHODS

A literature search of Medline, Scopus, Embase and Google Scholar for articles published from inception to 25 January, 2023 was conducted. Only antibiotic stability studies conducted in vitro and not recently reviewed by So et al. were included. The main outcomes were chemical, physical, antimicrobial and microbial stability. This protocol was registered in PROSPERO (registration number CRD42023393366).

RESULTS

We screened 1254 abstracts, and 28 articles were included in the study. In addition to those discussed in a recent systematic review (So et al., Clin Kidney J 15(6):1071-1078, 2022), we identified 18 antimicrobial agents. Of these, 9 have intraperitoneal dosing recommendations in the recent International Society for Peritoneal Dialysis (ISPD) peritonitis guidelines, and 7 of the 9 had stability data applicable to clinical practice. They were cefotaxime, ceftriaxone, daptomycin, ofloxacin, and teicoplanin in glucose-based solutions, tobramycin in Extraneal solution only and fosfomycin in Extraneal, Nutrineal, Physioneal 1.36% and 2.27% glucose solutions.

CONCLUSIONS

Physicochemical stability has not been demonstrated for all antibiotics with intraperitoneal dosing recommendations in the ISPD peritonitis guidelines. Further studies are required to determine the stability of antibiotics, especially in icodextrin-based and low-glucose degradation products, pH-neutral solutions.

Daptomycin Pharmacokinetics in Adolescents Undergoing Hemodialysis and Peritoneal Dialysis: A Case Series With Pharmacokinetic Modeling

BACKGROUND

Children who undergo hemodialysis (HD) and peritoneal dialysis are at increased risk of infection. Daptomcyin is used to treat resistant infections; however, the pharmacokinetics of daptomycin in pediatric and adolescent dialysis patients remain unknown.

METHODS

We report the safety and pharmacokinetics of a single intravenous 5 mg/kg dose of daptomycin for 6 individuals age 12 to 17 years old who underwent HD or continuous cycling peritoneal dialysis (CCPD). Daptomycin concentrations from all samples were determined by high-performance liquid chromatography. A non-compartmental analysis was performed to compare the pharmacokinetic parameters among HD and CCPD patients. A population pharmacokinetic model was developed to describe the concentration-time profiles of daptomycin in plasma, urine, and dialysis effluent. Monte Carlo simulations were performed to assess the pharmacodynamic outcomes.

RESULTS

All subjects tolerated the single dose of daptomycin. During HD, significant drug removal was observed, compared with CCPD (26% vs 5% of total dose). A low daptomycin renal clearance (<12% of total clearance) with moderate variability (40.5%) was observed among subjects with residual renal function. An anuric and obese subject who received CCPD treatment appeared to have >80% higher daptomycin area under the plasma concentration-time curve than the other CCPD subjects. Dosing regimens that achieved predefined pharmacodynamic targets were reported.

CONCLUSIONS

Daptomycin clearance was faster in 12- to 17-year-old patients receiving HD than CCPD. Administration of daptomycin immediately after HD reduces drug loss. The CCPD treatment, anuria, and obesity may increase the risk for drug accumulation. Our pharmacokinetic model can be further used to optimize dosing regimens of daptomycin in this population.

Pharmacokinetics of Intraperitoneal Daptomycin in Patients with Peritoneal Dialysis-Related Peritonitis

Background

Antibiotics are preferentially delivered via the peritoneal route to treat peritoneal dialysis-related peritonitis (PDRP) to ensure that maximal concentrations are delivered to the site of infection. Our study focused on the pharmacokinetics of daptomycin (DAP) administered via the intraperitoneal (IP) route in patients with PDRP.

Methods

According to the DaptoDP protocol (Clinical Trial No. 2012-005699-33), IP DAP was administered daily, i.e., during the 6-h Nutrineal (Baxter Healthcare Corporation, Deerfield, IL, USA) dwell time period, for 14 days, in addition to administration of the antibiotics used for the usual care of patients with PDRP. The plasma and IP levels of DAP were measured on days 1 and 5. The tested dose was 200 mg/day. The principal endpoint was the dialysate concentration after 6 hours of dwell time > 16 mg/L (corresponding to 4 x minimum inhibitory concentration [MIC] for E. faecalis).

Results

Three participants were evaluated. On day 5, the IP concentrations after 6 hours of dwell time were between 6.3 and 23.4 mg/L, and the peak plasma concentrations were between 13.0 and 15.3 mg/L.

Conclusion

The results suggest that 200 mg/day is very likely sufficient for the treatment of PDRP by Staphylococci or Streptococci whereas it could be insufficient to treat PRDP by Enterococci. The good peritoneal bioavailability of DAP was quantitatively established, suggesting that IP administration could also be used as an alternate route for patients with damaged venous access. No DAP accumulation that could lead to toxic concentrations after repeated administration is expected, even in anuric patients. The protocol will further continue to assess whether a higher dose achieves the pharmacokinetic objectives.

Stability of daptomycin reconstituted vials and infusion solutions

OBJECTIVES

Daptomycin is a cyclic lipopeptide with selective action against drug-resistant Gram-positive bacteria. The stability of daptomycin solutions in different containers while stored at different temperatures was assessed.

METHODS

Daptomycin vials were reconstituted with NaCl (50 mg/mL). Daptomycin infusion solutions (5.6 and 14.0 mg/mL) were prepared in polypropylene infusion bags. All test solutions were stored either under refrigeration or at room temperature over 7 days. Samples were withdrawn on days 0, 2, 4 and 7 and assayed in triplicate using a stability-indicating high-performance liquid chromatography (HPLC) method.

RESULTS

The HPLC analysis revealed no significant loss in daptomycin concentration in vials or bags when stored at 2-8°C. All samples remained clear and colourless and there were no significant changes in pH throughout the study period.

CONCLUSIONS

Reconstituted daptomycin vials (50 mg/mL) and infusion bags (5.6 and 14 mg/mL) were found to be physicochemically stable over a period of 1 week when stored at 2-8°C.

Intracavitary and Systemic Daptomycin for Successful Treatment of a Postpneumonectomy Intrathoracic Infection

Treatment of an infected postpneumonectomy cavity is very difficult. We present a patient with an infection of a postpneumonectomy cavity by Staphylococcus epidermidis treated with local daptomycin for different dwell times, maintaining high antibiotic levels above the MIC. Clinical and microbiological cure were achieved successfully.

Newer antibiotics for the treatment of peritoneal dialysis-related peritonitis

Peritonitis is a debilitating infectious complication of peritoneal dialysis (PD). Drug-resistant bacterial peritonitis typically has a lower response rate to antibiotics. In the past 15 years, newer antibiotics with activities against drug-resistant Gram-positive bacteria have been developed. In most circumstances, peritonitis due to methicillin-resistant staphylococci responds to vancomycin. If vancomycin cannot be used due to allergy and/or non-susceptibility, there is increasing evidence that linezolid and daptomycin are the drugs of choice. It is reasonable to start linezolid orally or intravenously, but subsequent dose reduction may be necessary in case of myelosuppression. Daptomycin can be given intravenously or intraperitoneally and has excellent anti-biofilm activity. Other treatment options for drug-resistant Gram-positive bacterial peritonitis include teicoplanin, tigecycline and quinupristin/dalfopristin. Teicoplanin is not available in some countries (e.g. the USA). Tigecycline can only be given intravenously. Quinupristin/dalfopristin is ineffective against Enterococcus faecalis and there is only low-quality evidence to support its efficacy in the treatment of peritonitis. Effective newer antibiotics against drug-resistant Gram-negative bacteria are lacking. Polymyxins can be considered, but evidence on its efficacy is limited. In this review, we will discuss the potential use of newer antibiotics in the treatment of drug-resistant bacterial peritonitis in PD patients.

Stability of daptomycin in peritoneal dialysis solutions packaged in dual-compartment infusion bags

Background

Intraperitoneal daptomycin is used for the treatment of peritoneal dialysis (PD)-associated peritonitis caused by vancomycin-resistant bacteria. This study investigated the stability of daptomycin in a pH-neutral PD solution.

Methods

Reconstituted solution of daptomycin was added to a total of nine PD bags to obtain a concentration of 20 mg/L and stored at 1 of 3 different temperatures: 4 or 25°C for up to 168 h or 37°C for up to 48 h. Stabilities were determined by visual inspection, pH measurement and high-performance liquid chromatography.

Results

Daptomycin retained more than 90% of its initial concentration for 120, 72 and 12 h at 4°C, 25°C and 37°C, respectively. No physical precipitation or pH change was observed during the study.

Conclusions

Daptomycin in a pH-neutral PD solution is physically and chemically stable for 120 and 12 h at 4°C and 37°C, respectively.

The influence of different peritoneal dialysis fluids on the in vitro activity of ampicillin, daptomycin, and linezolid against Enterococcus faecalis

Intraperitoneal administration of antibiotics is recommended for the treatment of peritoneal dialysis-related peritonitis. However, little data are available on a possible interference between peritoneal dialysis fluids and the activity of antimicrobial agents. Thus, the present in vitro study set out to investigate the influence of different peritoneal dialysis fluids on the antimicrobial activity of ampicillin, linezolid, and daptomycin against Enterococcus faecalis. Time-kill curves in four different peritoneal dialysis fluids were performed over 24 h with four different concentrations (1 × MIC, 4 × MIC, 8 × MIC, 30 × MIC) of each antibiotic evaluated. Cation-adjusted Mueller-Hinton broth was used as the comparator solution. All four peritoneal dialysis fluids evaluated had a bacteriostatic effect on the growth of Enterococcus faecalis. Compared to the cation-adjusted Mueller-Hinton broth comparator solution, the antimicrobial activity of all antibiotics tested was reduced. For ampicillin and linezolid, no activity was found in any peritoneal dialysis fluid, regardless of the concentration. Daptomycin demonstrated dose-dependent activity in all peritoneal dialysis fluids. Bactericidal activity was observed at the highest concentrations evaluated in Dianeal® PDG4 and Extraneal®, but not in concentrations lower than 30 × MIC and not in Nutrineal® PD4 and Physioneal® 40. The antimicrobial activity of ampicillin and linezolid is limited in peritoneal dialysis fluids in vitro. Daptomycin is highly effective in peritoneal dialysis fluids and might, thus, serve as an important treatment option in peritoneal dialysis-related peritonitis. Further studies are needed to evaluate the clinical impact of the present findings.