Pivmecillinam and trimethoprim/sulfamethoxazole in the treatment of bacteriuria

In a double-blind study the antibacterial effect of pivmecillinam 600 mg b.i.d. was compared with that of co-trimoxazole (80+400) mg b.i.d. in elderly hospitalized patients with bacteriuria. Both drugs were administered orally for 6 days. Out of 46 patients (23 in each group) all were cured except two in the pivmecillinam group. At follow-up 6 to 8 weeks later approximately one-third of the patients in both groups was found to have a recurrence. No development or selection of resistant organisms was observed in either group. Nausea and vomiting were the only side-effects seen, occurring in one patient from each group. A single oral dose of 600 mg pivmecillinam produced a mean peak serum concentration of 4.6 μg mecillinam/ml within 2 h, which was halved 2 h later. The day to day variation in mean serum concentration curves of mecillinam, trimethoprim and sulfamethoxazole were almost identical. The patient to patient variation in the peak serum concentration of the three compounds did not exceed more than about 3 fold.