Treatment of pneumonia and other serious bacterial infections with cephapirin.

Nineteen patients with pneumonia due to Streptococcus pneumoniae, Staphylococcus aureus, Klebsiella pneumoniae, or Escherichia coli were treated with 4 to 18 g of cephapirin daily. There were three treatment failures. One patient each with pneumonia due to E. coli or S. pneumoniae died despite apparent eradication of the pathogen. Lobar pneumonia due to K. pneumoniae progressed during therapy in a third patient to lung gangrene, necessitating pneumonectomy. Five additional patients with pneumococcal pericarditis or septic bursitis, empyema, cannula-associated bacteremia, and thoractomy wound infection due to S. aureus were cured. All isolates of S. aureus, S. pneumoniae, and group A Streptococcus were inhibited by 0.8 mug of cephapirin per ml; minimal inhibitory concentrations of cephalothin were similar. Ninety percent of K. pneumoniae, 85% of Proteus mirabilis, 73% of E. coli, and 30% of Enterobacter were inhibited by 12.5 mug cephapirin per ml. All isolates of Pseudomonas, Serratia and indole-positive Proteus had a cephapirin minimal inhibitory concentration of [Formula: see text] 100 mug/mg. Serum concentrations after intravenous and intramuscular injection were similar to those reported for cephalothin. The intramuscular injections were moderately painful, and intravenous infusions caused phlebitis in three of nine patients treated with doses up to 18 g per day. Cephapirin appears comparable to cephalothin in vitro and is an effective agent in treatment of infection due to S. aureus and S. pneumoniae.