Cefamandole treatment of pulmonary infection caused by gram-negative rods.

The increasing incidence of pneumonia caused by H. influenza and the problem of beta lactamase production (18% of strains in recent reports) are important considerations in the therapy of pneumonia. An antibiotic that is effective for these strains and other common respiratory pathogens will be useful for the therapy of pneumonia. Cefamandole nafate is a new cephalosporin antibiotic with an antimicrobial spectrum similar to cephalothin with increased activity against Escherichia coli, Proteus spp., Enterobacter spp., and Haemophilus influenzae. Seventeen patients with pneumonia presumed to be due to susceptible gram-negative organisms isolated from transtracheal aspirate or sputum were treated with 6 to 8 g/day of parenteral cefamandole nafate. Organisms isolated were Haemophilus influenzae in 6, E. coli in 3, Proteus mirabilis in 2, Klebsiella pneumoniae in 1, Serratia marcescens in 1 and mixed gram-negative rods in 4. The Serratia were resistant (MIC greater than 100 microgram/ml and 50 microgram/ml): other MIC's ranged from 0.2 to 6.2 microgram/ml; median 1.6 microgram/ml. Satisfactory clinical response (improvement in pulmonary function; resolution of infiltrate; decrease in temperature, sputum production and white count) was noted in 13 of 17 patients. Two patients died from their underlying disease. Adverse clinical reactions questionably related to cefamandole included SGOT rises in 3 and rash in one. Serum antibiotic levels were 22.0 to 88.0 microgram/ml (peak) and 1.1 to 12.5 microgram/ml (trough). Sputum levels were 0.27 to 2.5 microgram/ml. Cefamandole appears to be an effective antibiotic for treatment of gram-negative pneumonia caused by susceptible organisms.