Bacteriological and clinical studies on biapenem

Abstract

We performed bacteriological and clinical studies on biapenem (BIPM), a new parenteral carbapenem antibiotic, with the following results.
1. Antibacterial activity
The MICs of BIPM against various clinical isolates were determined with an inculum size of 10⁶ cells/ml. The MIC₉₀ was 0.2μg/ml for methicillin-sensitive Staphylococcus aureus (MSSA), 100 for methicillin-resistant Staphylococcus. aureus (MRSA) and Enterococcus faecalis, 0.78 for Escherichia coil, Klebsiella pneumoniae and Citrobacter freundii, 1.56 for Enterobacter spp., 3.13 for Proteus spp., and 12.5 for Pseudomonas aeruginosa. Its activity against gram-positive cocci was almost the same as meropenem (MEPM), and less than imipenem (IPM) and panipenem (PAPM). Its activity against gram-negative rods was less than MEPM, but almost the same as PAPM, more potent than IPM.
2. Clinical efficacy
Two patients with acute bronchitis, 9 with pneumonia, 6 with chronic respiratory tract infection, 1 with sepsis, and 3 with pyelonephritis were treated with BIPM at a daily dose of 300-600mg for 3-22days. Clinical response was excellent in 2, good in 17, fair in 1 and unknown in 3 patients. The causative organisms were all eradicated. Eruption was seen in one patient, and elevation of RBC, Ht, basophil, eosinophil, GOT and ALP were noted in 3 patients.