Mezlocillin in the therapy of serious infections.

Abstract Mezlocillin, a new semisynthetic penicillin chemically related to ampicillin which is more active than carbenicillin against Ps. aeruginosa, B. fragilis and Strep. faecalis and which inhibits many Klebsiella, was evaluated in the therapy of 34 episodes of infection in 26 patients. Infection sites included pulmonary, urinary tract and tissue infections, including peritonitis. Seven patients had bacteremia. Clinical cures were achieved in 83 per cent and bacteria cures in 76 per cent of infections. Cure was achieved with mezlocillin in patients with infections caused by carbenicillin-resistant species. Adverse effects of therapy were minimal, one rash and one episode of reversible neutropenia. Serum and body fluid levels were easily maintained above the inhibitory levels of susceptible organisms. Mezlocillin was a safe, well tolerated and effective antibiotic in the treatment of infections due to susceptible organisms.