Daptomycin compatibility in peritoneal dialysis solutions

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.

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.

Compatibility of aztreonam in four commercial peritoneal dialysis fluids

The preferable route for treatment of peritoneal dialysis related peritonitis remains the intraperitoneal administration of antibiotics admixed to peritoneal dialysis fluids. It is important to know whether the administered drug is compatible with the PD fluids and its container. In the present study the compatibility of aztreonam with four commercial PDFs at storing temperatures and duration representative for storing conditions in the clinical settings was investigated. Aztreonam concentrations were determined using high-performance liquid chromatography. The antimicrobial activity of aztreonam was evaluated using an E. coli diffusion disk inhibition assay and P. aeruginosa time-kill curves. In Extraneal evaluated at 6 °C, 25 °C and 37 °C aztreonam was stable over the whole study period of 14 days and 24 hours, respectively. In Physioneal and Nutrineal aztreonam was stable at 6 °C for up to 14 days. Antimicrobial activity was retained in all PD fluids over the whole study period. Aztreonam remained stable and was compatible with the PD fluids, particularly with Extraneal or Nutrineal, and no compensatory dose adjustment is needed when stored for up to 14 days at refrigeration temperature before use.

Effect of High Blood Glucose Level on the Antimicrobial Activity of Daptomycin against Staphylococcus aureus in Streptozotocin-Induced Diabetic Mice

Daptomycin is active against Staphylococcus aureus including methicillin-resistant S. aureus (MRSA), demonstrating efficacy in the treatment of infections in diabetic patients. However, daptomycin degrades in 5% glucose solution, and data on the efficacy of daptomycin in hyperglycemic patients are limited. Therefore, we investigated the effect of high levels of blood glucose on the efficacy and concentration of daptomycin. The efficacy of simulated human exposure to daptomycin against S. aureus was compared in a neutropenic murine thigh model, with and without hyperglycemia. A clinically isolated MRSA strain and S. aureus ATCC25923 standard strain were used. Daptomycin concentrations, in the serum and at the infected site, were preliminarily analyzed using the high-performance liquid chromatography assay. Even in hyperglycemic mice, the mean concentration of daptomycin in hyperglycemic mice was equivalent to that in untreated mice within the physiological blood glucose levels. Additionally, the efficacy of daptomycin against MRSA was equal to that observed in the untreated and hyperglycemic mice. Based on similar studies using S. aureus ATCC25923, the efficacy in hyperglycemic mice was equal to or greater than that observed in untreated mice. In conclusion, daptomycin is an alternative therapeutic option in diabetic mice with serious staphylococcal infections, regardless of blood glucose control in this animal model.

Pharmacokinetics of 300 mg/d Intraperitoneal Daptomycin: New Insight from the DaptoDP Study

The DaptoDP (NCT 2012-005699-33) study aimed to evaluate the pharmacokinetic parameters of daptomycin (DAP) in peritoneal dialysis-related peritonitis (PDRP) patients following intraperitoneal (IP) administration. The authors have already reported the findings on the 200-mg dosing and present here the follow-up results of the 300-mg dosing. The primary endpoint was a dialysate concentration of DAP above the effective concentration in situ during 6 hours of dwell time i.e., 16 mg/L. Secondary endpoints were to avoid the toxic threshold of 120 mg/L DAP and to be above 16 mg/L DAP for 2 hours in plasma. Pharmacokinetic parameters were evaluated on days 1 and 5. Safety data were evaluated on days 1 to 14 based on clinical and biological parameters. Daptomycin was administered in Nutrineal during 6 hours of dwell time for 14 days plus the usual antibiotic therapy in a separate dwell. Because the 200-mg dosing objectives were not reached, a higher DAP dose of 300 mg was tested in the next 3 patients. Effective dialysate and plasma concentrations were achieved at the 300-mg DAP dose with the plasma concentration well below the toxic threshold, even at steady state, during which the accumulation factor never exceeded 3. The optimal DAP dose of 300 mg daily by the IP route, as determined by the pharmacokinetic data, needs to be clinically confirmed prior to routine use. The peritoneal bioavailability of DAP supports using the IP route as an alternative to the intravenous route for peritonitis and systemic infections.

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.

Successful Treatment of a Pacemaker Infection with Intraperitoneal Daptomycin

We investigated the pharmacokinetics of intraperitoneal administration of daptomcyin in a peritoneal dialysis (PD) patient treated for a pacemaker infection with Staphylococcus epidermidis. After initial start of intravenous daptomycin at 9 mg/kg body weight every 48 hours, the therapy was switched to intraperitoneal administration of 5.3 mg/kg body weight in 1 L icodextrin 7.5% with a dwell time of 12 hours overnight every 48 hours. Therapeutic drug monitoring (TDM) was performed at 4 hours and 24 hours after dose administration. Due to high peak concentration above target peak concentration, the dose was reduced to a final maintenance dose of 3.2 mg/kg body weight. Data from this single case suggest that serum drug concentration above the minimal inhibitory concentration (MIC) can be easily achieved with intraperitoneal administration of daptomycin every 48 hours even with a lower dose, as recommended for the intravenous administration, but measurement of serum concentration and dose adjustments are mandatory in such cases.

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.

Treatment of enterococcal peritonitis with intraperitoneal daptomycin in a vancomycin-allergic patient and a review of the literature

BACKGROUND

Intraperitoneal (IP) administration of antibiotics is a mainstay of therapy in the treatment of peritoneal dialysis-related peritonitis. The therapeutic options against gram-positive organisms in patients intolerant to vancomycin are limited.

METHODS

This case report and review of the literature used a search of PubMed with the terms "daptomycin," "intraperitoneal," and "peritoneal" for 2004 through 7 February 2013 to find relevant publications.

RESULTS

In addition to our patient, we identified 6 case reports of IP daptomycin for the treatment of peritonitis. Our patient was treated with a 14-day course of IP daptomycin, with resolution of signs and symptoms of peritonitis. She presented again 7 weeks later with signs and symptoms of peritonitis and was treated with a repeat course of IP daptomycin. Among the 6 patients reported in the literature, 4 received loading doses of daptomycin. Daptomycin 20 mg per liter of dialysate was administered in 4 patients, and the other 2 patients received higher doses based on body weight (milligrams per kilogram). Treatment duration averaged 10 or 14 days. In all 6 cases, clinical cure was reported.

CONCLUSIONS

Although limited to case reports, the available literature suggests that IP daptomycin is a viable alternative for peritoneal dialysis-related peritonitis. However, routine use of this agent must be cautioned, because further prospective studies are required.