Pharmacokinetic considerations for treatment of bacterial peritonitis during continuous ambulatory peritoneal dialysis

Compatibility of fosfomycin with different commercial peritoneal dialysis solutions

For treatment of peritoneal dialysis-related peritonitis, intraperitoneal administration of antibiotics remains the preferable route. For home-based therapy, patients are commonly supplied with peritoneal dialysis fluids already containing antimicrobial agents. The present study set out to investigate the compatibility of fosfomycin with different peritoneal dialysis fluids, namely, Extraneal^®, Nutrineal^®, Physioneal^® 1.36% and Physioneal^® 2.27%, under varying storage conditions. The peritoneal dialysis fluid bags including 4 g fosfomycin were stored over 14 days at refrigeration temperature (6°C) and room temperature (25°C) and over 24 h at body temperature (37°C). Drug concentrations over time were determined by using high-performance liquid chromatography coupled to a mass spectrometer. In addition, drug activity was assessed by a disk diffusion method, diluent stability by visual inspection and drug adsorption by comparison of the measured and calculated concentrations. Blank peritoneal dialysis fluids and deionized water were used as comparator solutions. Fosfomycin was stable in all peritoneal dialysis fluids and at each storage condition investigated over the whole study period. The remaining drug concentrations ranged between 94% and 104% of the respective initial concentrations. No significant drug adsorption was observed for any peritoneal dialysis fluid at any storage condition. No relevant reduction of antimicrobial activity was observed. Fosfomycin is compatible with Extraneal^®, Nutrineal^® and Physioneal^® for up to two weeks at refrigeration or room temperature and may be used for home-based therapy. No dose adjustment is needed due to adsorption or degradation.

Cefotaxime. A reappraisal of its antibacterial activity and pharmacokinetic properties, and a review of its therapeutic efficacy when administered twice daily for the treatment of mild to moderate infections

Cefotaxime is well established as an effective and well tolerated antibacterial drug for 3 times daily parenteral treatment of a variety of moderate to severe infections in hospitalised patients. Its frequency of administration has recently been reassessed with a 12-hourly regimen. Comparative studies in hospitalised patients with nosocomial or community-acquired lower respiratory tract infections, demonstrate the similar clinical and bacteriological efficacy of twice daily cefotaxime 1 or 2 g and the same daily dose of ceftriaxone, usually administered once daily. Cefotaxime 2 g twice daily was also similar in efficacy to ceftriaxone 2 g once daily. Retrospective and post-marketing studies also reveal the similar efficacy of cefotaxime administered twice and 3 times daily, and pharmacoeconomic studies suggest that total direct costs of treatment with cefotaxime compared is similar to that with other third generation cephalosporins in currently used dosage regimens. When administered twice daily, cefotaxime is, thus, an effective antibacterial agent for the treatment of hospitalised patients outside the intensive care unit with a variety of mild to moderate non-CNS infections caused by susceptible organisms. When appropriately administered twice daily there is potential to lower the cost of antibacterial treatment without compromising efficacy.

Comparison of a fluorescence polarization immunoassay of netilmicin in plasma, peritoneal dialysate, and urine with a high-performance liquid chromatographic method

The quantitative analysis of netilmicin in plasma, peritoneal dialysate, and urine using the fluorescence polarization immunoassay (FPIA) of the Abbott TDx system is compared with the modified high-performance liquid chromatography (HPLC) method of Peng et al., which was chosen as a reference. Using the least square method, we found that the results of the FPIA (y) correlated well with those obtained with HPLC (x). The three regression equations for the plasma, peritoneal dialysate, and urine samples, respectively, were y = 0.71x + 0.44 with r = 0.88 and n = 45; y = 0.94x + 1.22 with r = 0.93 and n = 95; and y = 0.92x + 0.70 with r = 0.93 and n = 61. The corresponding mean errors (FPIA-HPLC) with their 95% confidence intervals were -0.19 (-0.38 to -0.02), 0.69 (-0.42 to 1.81), and -0.13 (-1.13 to 0.87) microgram/ml. According to results of the Wilcoxon matched-pairs signed-ranks test, these errors did not represent a significant bias. The FPIA is thus suitable for analyzing netilmicin in the three biological fluids studied except when dialysate is contaminated with Amuchina. In this case, HPLC should be used.

Pharmacokinetics of cefotaxime in dialysis patients

A literature review was carried out to assess the effect of hemodialysis, hemofiltration, and continuous ambulatory peritoneal dialysis on the pharmacokinetics of cefotaxime, particularly in patients with severe renal impairment. It was concluded that the dosage of cefotaxime, adjusted for renal function, would require no further adjustment during peritoneal dialysis or hemofiltration.

Clinical Pharmacy Care in Continuous Ambulatory Peritoneal Dialysis Patients

Continuous ambulatory peritoneal dialysis (CAPD) continues to grow as a treatment modality for end-stage renal disease (ESRD). The high cost of care, multiplicity of drugs used by each patient, high cost of individual drugs, and high incidence of complications, make this patient population a challenging area for clinical pharmacy input. This article discusses the mechanics of CAPD, together with patient selection criteria, monitoring of the dialysis prescription, and infectious complications. The potential for research involving clinical pharmacists is discussed. Apart from studies on the pharmacokinetic disposition of drugs administered to CAPD patients, there remains a relative lack of information on many aspects of drug therapy. Recommendations for areas of continued study include the optimization of antibiotic therapy for peritonitis and exit-site infections, use of the intraperitoneal route for systemic effects of drugs, quality-of-life investigations, and stability studies of drugs in dialysate.