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Background Intraperitoneal (IP) administration of ceftazidime is recommended for the treatment of peritoneal dialysis-associated peritonitis (PDAP) from Pseudomonas. Patients with PDAP may also need IP heparin to overcome problems with drainage of turbid peritoneal dialysis (PD) fluids and blockage of catheters with fibrin. Physico-chemical stability of ceftazidime and heparin, and biological stability of heparin in many types of PD solutions is unknown. Therefore, we investigated the stability of ceftazidime and heparin in 4 types of PD solutions.Methods A total of 12 PD bags (3 for each type of solution) containing ceftazidime and heparin were prepared and stored at 4°C for 120 hours, and then at 25°C for 6 hours, and finally at 37°C for 12 hours. An aliquot was withdrawn after predefined time points and analyzed for the concentration of ceftazidime and heparin using high-performance liquid-chromatography (HPLC). Samples were assessed for pH, color changes, particle content, and anticoagulant activity of heparin.Results Ceftazidime and heparin retained more than 91% of their initial concentration when stored at 4°C for 120 hours followed by storage at 25°C for 6 hours and then at 37°C for 12 hours. Heparin retained more than 95% of its initial activity throughout the study period. Particle formation was not detected at any time under the storage conditions. The pH and color remained essentially unchanged throughout the study.Conclusions Ceftazidime-heparin admixture retains its stability over long periods of storage at different temperatures, allowing its potential use for PDAP treatment in outpatient and remote settings.

Introduction Intraperitoneal tigecycline is a potential option for the treatment of peritoneal dialysis (PD)-associated peritonitis caused by microorganisms resistant to commonly used antibiotics. However, the stability of tigecycline must be assessed in the PD solution before evaluating its safety and therapeutic efficacy in PD-associated peritonitis. The objective of this study was to investigate the stability of tigecycline in 3 types of PD solutions at different temperatures for various time points.Methods A total of 27 PD bags (9 PD bags for each type of PD solution; 1.5% glucose, 7.5% icodextrin, and 1.5% glucose pH neutral) containing 2 μg/mL of tigecycline were prepared and stored at either 4, 25, or 37°C. An aliquot was withdrawn immediately before (0 hour) and after pre-defined time points. Each sample was analyzed in duplicate for the concentration of tigecycline using a stability-indicating high-performance liquid chromatography (HPLC) technique. Samples were also assessed for pH, color changes, and evidence of precipitation immediately after preparation and on each day of analysis.Results Tigecycline in all 3 types of PD solutions retained more than 90% of its initial concentration for at least 216, 72, and 8 hours at 4, 25, and 37°C, respectively. There was no evidence of precipitation at any time under the tested storage conditions. The pH and color of tigecycline admixed PD solutions stored at 4, 25, and 37°C remained essentially unchanged for 336, 96, and 48 hours respectively.Conclusion The results obtained from the study provide a platform for future clinical studies aiming to determine the safety and therapeutic efficacy of intraperitoneally administered tigecycline for the treatment of PD-associated peritonitis.

To evaluate a program to discontinue intravenous antibiotics at two teaching hospitals, 102 inpatients meeting eligibility criteria were randomly assigned to two groups. In one group, patients' physicians were contacted by pharmacists with recommendations to discontinue intravenous antibiotic therapy; in the other, patients were simply observed. Measured outcomes were antibiotic costs, length of stay, need to restart intravenous antibiotics, in‐hospital mortality, and 30‐day readmissions. The intervention significantly reduced mean antibiotic costs per patient ($19.82 vs $35.84, p=0.03), but related labor costs exceeded this benefit. Readmissions were significantly more frequent in the intervention group than in the control group (29% vs 9.8% p=0.02), but they were not infection related. No impact was demonstrated on the other measured outcomes. Institutions considering such programs or with one in place should conduct similar evaluations.

The imported red fire ant (Solenopsis invicta) is a problematic pest in the Southern United States. The stages of development for these ants are as follows: egg, 1st, 2nd, 3rd, and 4th instar larvae, prepupae, pupae, and adult. The 4th instar larvae plays an important role in the survival of the colony in that it is totally responsible for the digestion of solid foods and the source of nutrients for the queen and adult workers. In our studies we have been successful in purifying and characterizing four proteinases from the 4th instar larvae. Based on substrate specificity, they appear to represent two chymotrypsin-like and two elastase-like proteinases. These are referred to as Soli C1, Soli C2, Soli E1, and Soli E2, with molecular masses of 25, 28, 23, and 24 kDa, respectively, based on SDS-PAGE. All enzymes were inhibited by diisopropyl fluorophosphate, a general serine class inhibitor. Various synthetic substrates with either Phe or Val in the P1position, were readily cleaved by Soli C1/C2 or E1/E2, respectively. Each enzyme has been characterized as to pH optimum, pH stability, isoelectrofocusing and susceptibility to inhibition by a broad range of natural and synthetic proteinase inhibitors. Such compounds may prove useful for the development of insecticides to control fire ant infestation.