Cefpimizole

High-performance liquid chromatography was used to determine the penetration of 19 antimicrobial agents into human polymorphonuclear leukocytes. The ratios of the intracellular concentration to the extracellular concentration of ampicillin, piperacillin, cefazolin, ceftizoxime, cefpimizole, and ceftazidime were all less than 0.6. Lincomycin showed a high intracellular-to-extracellular ratio (3.0), while clindamycin achieved a ratio of 15.5, which was the highest ratio of all of the 19 tested antibiotics. Ratios for rifampin, isoniazid, chloramphenicol, and trimethoprim were 8.2, 1.1, 9.6, and 6.1, respectively. Six quinolone-class antimicrobial agents had ratios from 2.2 to 8.2. Flucytosine showed a penetration ratio of 4.6. Clindamycin uptake was temperature dependent and occurred best with live polymorphonuclear leukocytes; sodium fluoride, adenosine, and puromycin were inhibitory. The results obtained in this study correlate well with the results of other studies involving radioisotopic methods.

In order to clarify the mechanisms of the in vivo antibacterial activity of a cephalosporin, cefodizime (CDZM), the effect of this antibiotic on Pseudomonas aeruginosa E7 infection was examined in rats whose neutrophils had been selectively depleted by monoclonal antibody RP-3. CDZM was less effective in RP-3-treated rats than in untreated rats. However, treatment of rats with recombinant human granulocyte-colony stimulating factor (rhG-CSF) augmented the in vivo activity of this antibiotic. Furthermore, the in vivo antibacterial activity of two other cephalosporins, cefpimizole (CPIZ) and cefoperazone (CPZ), was bilaterally affected by a rise or fall in the neutrophil number, although to a lesser degree than was the case with CDZM. Taken together, neutrophils play an important role in the in vivo antibacterial activity of certain cephalosporins.

Cefpimizole natrium (CPIZ), an antibiotic belonging to the cephalosporins, was examined regarding its influence on neutrophil functions. Neutrophil superoxide (O2-) generation increased by intravenous CPIZ in patients with maxillofacial diseases. In vitro examination revealed that CPIZ directly stimulates neutrophils to generate O2- in a dose-dependent manner, though the induction ability is not as strong as phorbol myristate acetate (PMA). Protein kinase C (PKC) activity in the neutrophil plasma membrane increased after CPIZ treatment, while the activity in the cytosol fraction decreased. CPIZ cooperated with biological response modifiers (BRMs) such as sizofilan, lentinan, OK-432, rIL-2 and rIFN-gamma in neutrophil O2- generation. Non-specific cytotoxicity against K562 cells and candida cells was also enhanced by neutrophil pretreatment with both CPIZ and one of the BRMs except for sizofilan and rIL-2. From these results it can be concluded that CPIZ directly enhanced neutrophil O2- generation and that these CPIZ activations are further beneficial to protection against bacterial infections.

We evaluated the ingestion of anti-sheep erythrocyte (anti-E) IgG- and IgM-coated sheep erythrocytes by murine peritoneal macrophages exposed to cefodizime, a new semisynthetic cephalosporin, and other antibiotics. Cefodizime enhanced the ingestion of anti-E IgG-coated erythrocytes by peritoneal macrophages from CD-1 and BALB/c mice in a dose-dependent manner, but had no effect on uncoated or IgM-coated erythrocytes. Similar enhancement was observed only in the case of cefpimizole (AC-1370), among the other antibiotics examined. These results suggest that the favorable in vivo activity of cefodizime and cefpimizole may result from their phagocytosis-enhancing as well as antimicrobial properties.