[A study on serum level and urinary excretion of fosfomycin-Na in man with special reference to pharmacokinetic analysis (author's transl)].

FOM-Na was investigated on its distribution after a continuous intravenous drip infusion in 3 healthy adult volunteers, and its serum levels and urinary excretion were pharmacokinetically analyzed, while the excreted substance into urine was also analyzed with GC/MS. The results obtained are summarized as follows: 1. The distribution volume of FOM-Na in one-compartment open model was 0.183 L/kg, half life in human body 1.66 hours and renal clearance 0.0737 L/hr/kg. 2. With these pharmacokinetic constants, the mean values following various doses demonstrated almost equal irrespective of its dosage schedule, keeping an almost constant level in each individual tested. 3. The area under serum level-time curve was approximately 216 microgram.hr/ml per 1 g (potency), and increased in proportion to an infused dose within the range of 1 approximately 6 g (potency). Three consecutive administrations showed no trend of accumulation of the agent in the serum. 4. Urinary excretion of the agent was found to be very fast, and its recovery rate from urine within 10 approximately 11 hours after the completion of an i. v. drip infusion was approximately 95 approximately 99%. 5. As a result of GC/MS on the substance excreted into urine, it was noted that FOM-Na was not metabolized in human body and excreted into urine in its original form. 6. There was seen no specific change in electrocardiogram during and/or after an intravenous drip infusion in 1 hour of 2 g (potency) FOM-Na dissolved in a 300 ml 5% glucose solution.