Randomised comparison of ceftriaxone and cefamandole therapy in lower respiratory tract infections in an elderly population

Patients with pneumonia or bronchitis were randomized to receive ceftriaxone or cefamandole. A total of 30 of 38 patients were evaluable, 16 in the ceftriaxone group (average age 66.3 years) and 14 in the cefamandole group (average age 69.4 years). All but one had underlying diseases. Patients usually received 1 g of ceftriaxone intravenously every 12 h (mean duration 8.7 days) or 1.5 g of cefamandole intravenously every 6 h (mean duration 8.2 days). Adverse experiences attributable to the drugs were confined to one episode of discomfort at the infusion site in each group. Bacteriological results with ceftriaxone were 83% cured, 11% superinfected after eradication of pretherapy isolate, and 6% failed. Bacteriological results with cefamandole were 76% cured, 24% failed. Clinical results with ceftriaxone were 38% cured, 56% improved, 6% failed. Clinical results with cefamandole were 57% cured, 21% improved, 21% failed. Emergence of a resistant Serratia marcescens was seen in a ceftriaxone-treated patient. Disc diffusion susceptibility testing identified six of the seven pretherapy nonfastidious Gram-negative isolates as susceptible; however, two of the six could not be eradicated with the assigned drug and another two were eradicated with ensuing super-infection with susceptible isolates of Pseudomonas aeruginosa. In contrast, MBCs were an accurate guide to clinical outcome with nonfastidious Gram-negative bacilli.