Studies on cefuroxime axetil (CXM-AX)-its skin tissue levels and clinical efficacy

The fundamental and clinical studies were performed on Cefuroxime axetil (CXM-AX, SN 407), a new oral cephalosporin, prodrug of Cefuroxime (CXM). The results are summarised below. 1. The mean serum levels of CXM at 120–150 minutes after oral administration of 250 mg and 500 mg of CXM-AX were 3. 25 μg/ml and 4. 30 μg/ml, and the corresponding mean skin tissue levels were 1.46 μg/g and 2.14 μg/g, respectively. The rates of transfer of CXM into skin tissues were 44.9% and 59.5%, respectively, showing dose response between 250 mg and 500 mg groups. 2. Out of 234 cases assessable for clinical efficacy, 122 cases were assessed as Cured, 58 Remarkably Improved, 28 Moderately Improved, 20 Slightly Improved, 5 Unchanged and 1 Aggravated, with the efficacy rate (“Moderately Improved” or better) being 88. 9%. When the clinical efficacy was compared among groups of different diagnosis, the efficacy rates were 81.4% (35/43) in the Group I, 92.5% (37/40) in the Group II, 95.7% (22/23) in the Group III, 90.9% (40/44) in the Group IV, 94.6% (53/56) in the Group V and 75. 0% (21/28) in the Group VI. 3. Concerning the bacteriological response of the causative organisms, isolated from 169 patients, the bacterial elimination rate was 92. 3% (132/143). The MIC peaks of CXM, against 96 strains of S. aureus and 39 strains of coagulase negative staphylococci (CNS), both of which were the major clinical isolates, were 1.56 μg/ml and 0. 78 μg/ml, respectively. The antibacterial activity of CXM was higher than that of Cephalexin (CEX) and comparable to that of Cefaclor (CCL). 4. Among 245 cases in which the safety of the drug was evaluated, adverse events were observed in 17 cases (6. 9%), most of them being gastrointestinal tract symptoms, c. g. diarrhoea, loose stool and gastric pain. The abnormal laboratory findings were noted in a total of 11 cases, i. e. decrease in WBC counts in 2 cases (1.4%), increase in eosinophil counts in 1 (0.7%), elevation of hepatic transaminase levels in 7 (5. 0%) and positive reaction in direct Coombs’ test in 1 (5. 6%).