The safety and tolerance of azlocillin

631 patients treated with azlocillin were evaluated for adverse reactions. Azlocillin doses ranged from 37-714 mg/kg/day (mean 260 mg/kg/day) and duration of treatment ranged from 1 to 276 days (mean 11.1 days). 82% of patients were treated for more than 7 days. 92 (14.6%) experienced systemic and 20 patients (3.2%) experienced local adverse reactions. Hypersensitivity, manifest by drug fever, cutaneous reactions, or eosinophilia occurred in 0.3, 1.8 and 1.1%, respectively. Hypokalemia developed in 0.5% overall and was dose and duration related. Hepatotoxicity occurred in 1.7%, diarrhea in 1.9% and leukopenia in 0.3%. Nephrotoxicity, expressed as elevated serum creatinine, was seen in 0.5%. Bleeding was seen in one group of patients that received cefamandole concomitantly. As these complications were not seen in other patients, these complications are probably due to cefamandole. In comparison with ticarcillin, carbenicillin, piperacillin, and mezlocillin, a similar number and severity of adverse reactions were seen. Although the incidence of certain adverse reactions may be underestimated due to the short duration of therapy, azlocillin appears to be exceptionally safe and well tolerated.