A comparative trial of pivmecillinam and ampicillin in bacteriuria of pregnancy.

A comparative trial of pivmecillinam and ampicillin was performed on 100 women with bacteriuria of pregnancy. They received either 400 mg pivmecillinam four times daily or 500 mg ampicillin four times daily for seven days. Cure rates at two weeks were 88% in the pivmecillinam group and 85% in the ampicillin group. At six weeks the respective rates were 76% and 64%. Failure of therapy was not associated with the appearance of bacterial resistance in either treatment group. Side-effects, particularly vomiting and premature cessation of therapy, were significantly more frequent in the pivmecillinam group. No significant effects on liver function were found. In subsequent patients treated in a non-comparative manner with 200 mg pivmecillinam three times daily, the incidence of side effects was markedly reduced with no loss of efficacy.