Fosfomycin-ampicillin versus gentamicin-ampicillin in the treatment of critically ill patients with pneumonia.

Thirty-two patients with severe pneumonia (22 on assisted ventilation) were entered into a prospective randomised trial, in which fosfomycin plus ampicillin (17 patients) was compared with gentamicin plus ampicillin (15 patients). Treatment was either 4 g fosfomycin or 80 mg gentamicin every 8 h and 1 g ampicillin every 6 h. Complete or partial clinical success was attained in 94% (16/17) in the fosfomycin group and in 80% (12/15) in the gentamicin group. Bacteriological success was 87.5% with fosfomycin-ampicillin and 90% with gentamicin-ampicillin. An intermediary sensitive Klebsiella pneumoniae strain developed complete resistance in the fosfomycin group, and an in vitro sensitive Pseudomonas aeruginosa strain was resistant in vivo in the gentamicin group. Two of three patients in the fosfomycin group receiving the infusion through a peripheral vein developed thrombophlebitis. No other side-effects were observed. We conclude that fosfomycin is at least as effective as gentamicin. Since fosfomycin is widely atoxic and may be given in large doses, irrespective of kidney function, it is considered to have advantages over gentamicin in the combined therapy of pneumonia.