Serum Concentration of Flomoxef in Administration of One Hour Infusion Every Eight Hours a Day
Flomoxef (FMOX) is a new, parenteral oxacephem antibiotic with strong, broad-spectrum antimicrobial activity. To compensate for short half time of this drug, multi-divided administration of the drug was attempted, and the concentrations of FMOX in the blood were determined. The treatment by dripping intravenous infusion of FMOX thrice daily or one hour infusion every eight hours were carried out in six patients with an indwelling intravenous catheter. Four patients had pneumonia and the other two suffered from respiratory infections with lung cancer. With the patient's permission, six blood samples were drawn from each patient just before and after infusions, and the concentration of FMOX was determined by bioassay. The mean serum concentration in the six patients ranged between three troughs just before infusion and three peaks just after infusion, being 1.40 μg/ml, 2.59 μg/ml and 1.84 μg/ml, and 47.32 μg/ml, 52.17 μg/ml and 50 μg/ml, respectively. These concentrations, even troughs, were higher than the MIC90 of almost all bacteria considered to be sensitive to FMOX. In fact, five out of six patients showed a good response to this treatment. No side effects were observed, except mild and transient elevation of transaminase in one case. In conclusion, we recommend the administration of FMOX thrice daily for patients with severe pulmonary infections, especially from the standpoint of its blood concentration.