[Investigation of panipenem/betamipron levels in sera and various tissues in patients of orthopedic surgery].

Panipenem/betamipron (PAPM/BP), a new parenteral carbapenem antibiotic, was investigated with regard to their levels in sera and various tissues collected from patients under orthopedic surgery. The subjects were 17 patients, complaining low back pain and hospitalized for surgical operations. PAPM/BP was administered by intravenous drip infusion for 30 minutes of a dose of 500 mg/500 mg. Serum and cerebrospinal fluid (CSF) specimens were taken from 8 patients at 15-70 minutes after administration and assayed for PAPM and BP levels. Serum, bone, and joint capsule samples where taken from the other 9 cases at 25-127 minutes after administration and assayed. PAPM levels in CSF were considerably lower than those in serum. They were 23.74-1.11 micrograms/ml in sera, 0.31-0.05 micrograms/ml in CSF's during 15 to 70 minutes after administration. PAPM levels were 27.85-2.97 micrograms/ml in sera, 2.54-0.20 micrograms/g in bones, 5.63 and 1.67 micrograms/g in joint capsules during 25 to 127 minutes after administration. BP levels in sera and various tissues were low compared to those of PAPM. These results showed that PAPM was detected at higher levels than 0.2 microgram/g in various tissues, except CSF during 20 to 120 minutes after drip infusion of PAPM/BP 500 mg/500 mg for 30 minutes.