Aztreonam in the treatment of serious gram-negative infections in the elderly.

The efficacy and safety of aztreonam in the treatment of serious gam-negative infections were investigated in 20 patients, 19 of whom were more than 60 years old. There were 13 cases of upper urinary tract infection, 6 of septicemia and one of peritonitis. Half the patients were in a critical clinical condition with significant severe underlying disease. Aztreonam was given i.v. or i.m. in doses ranging from 1.5 to 4 g/day according to the severity of the infection. The duration of treatment ranged from 7 to 20 days. In 5 patients with mixed infections due to gram-positive and anaerobic organisms in addition to gram-negative pathogens, aztreonam was given in combination with clindamycin and metronidazole as appropriate. Clinical and bacteriological cures were observed in all 20 patients. There were two cases of reinfection and 3 of superinfection--all occurred in patients with severe underlying disease. Untoward effects were few and of minor severity. Creatinine clearance remained stable or improved during aztreonam treatment, even in patients with significant renal impairment. In conclusion, aztreonam was shown to be both effective and safe in the treatment of serious gram-negative infections in elderly patients--even those with impaired renal function. In such indications aztreonam appears to be a good alternative to potentially toxic drugs such as the aminoglycosides.