Ceftazidime in the treatment of serious Pseudomonas aeruginosa sepsis.

28 patients with serious Pseudomonas aeruginosa sepsis were enrolled into a prospective open study using ceftazidime (CAZ). 10 patients had rapidly fatal underlying pathology, including 5 neutropenic (neutrophils less than 1.0 X 10(9)/l) patients with malignancy. 9 patients including all those with neutropenia also received concomitant therapy with other active antipseudomonal antibiotics (mainly aminoglycosides). All isolates were initially sensitive to CAZ. A favourable response was seen in 18/27 (67%) evaluable cases. Genitourinary infection and osteomyelitis responded well with 100% and 83% favourable responses respectively. Soft tissue and respiratory tract infection responded less well. Results with biliary sepsis were disappointing (all 3 failed therapy). Of the 9 patients failing treatment 5 responded to alternative antibiotics (usually combination therapy of ureidopenicillin plus aminoglycoside). 2 died primarily from underlying pathology and 2 as a direct result of Ps. aeruginosa sepsis. Toxicity was minimal. In the few cases observed other agents and underlying pathology possibly contributed. The most disturbing feature of the study was the emergence of multiple beta-lactam resistance in organisms whilst treated with CAZ. 5 cases occurred, 4 in the infected strain and 1 in a superinfecting strain, occurring in 4 patients within 10 days of starting therapy. 2 cases occurred in patients receiving concomitant aminoglycosides.