Ampicillin plus mecillinam vs. cefotaxime/cefadroxil treatment of patients with severe pneumonia or pyelonephritis: a double-blind multicentre study evaluated by intention-to-treat analysis.

In this double-blind multicentre study, using the intention-to-treat approach, a total of 293 patients with fever (> or = 38.5 degrees C), symptoms of sepsis and signs of pneumonia or pyelonephritis were randomly assigned to treatment with ampicillin and mecillinam (A+M) or cefotaxime followed by cefadroxil. In the febrile phase, treatment was given intravenously twice daily, either with 1,200 mg ampicillin together with 600 mg mecillinam or with 2 g cefotaxime alone. When the patients stayed afebrile, the intravenous administration was replaced by oral treatment twice daily for 14 days, either with 500 mg pivampicillin and 400 mg pivmecillinam or 1 g cefadroxil. In the A+M group, 33% (48/144) of the patients did not complete the full course of treatment as compared with 32% (47/149) in the cephalosporin group, the reasons being treatment failure in 27 and 29, respectively, or adverse effects (n = 16 in both groups). The median duration of fever was 47 h in the A + M group and 50 h in the cephalosporin group. Of 135 patients with pneumonia, 68% were completely cured in the A + M group, and 65% in the cephalosporin group, the main reasons for treatment failure being Mycoplasma pneumonia or ornithosis. Of 136 patients with pyelonephritis, 63% were cured in each group. The main reason for failure was bacteriological relapse. Side-effects were reported by 32 patients (22%) of the A+M group, as compared with 41 (28%) of the cephalosporin group. Epigastric complaints were equally frequent in both groups, but there was a tendency for a higher frequency of exanthema in the A+M group, and for antibiotic-associated diarrhoea and fungal superinfections in the cephalosporin group.