Abstract
Fundamental and clinical studies of pipemidic acid (PPA) were made with the following results.
1. In vitro antibacterial activity of PPA was compared with that of piromidic acid (PA), β-hydroxypiromidic acid (β-OHPA) and nalidixic acid (NA) using 242 strains isolated from various infections in the field of obstetrics and gynecology. Most of gram-negative bacteria were inhibited by 6.25 μg of PPA per ml which were generally more active than PA, β-OHPA and NA. About 50 % of pseudomonads was inhibited by 50 μg of PPA per ml, whereas more than 90% was resistant to 100 pg of PA, β-OHPA or NA per ml.
2. Concentrations of PPA in various tissues and body fluids were determined after a single oral administration of 250 mg. Its peak levels were about 2-3 μg/ml in maternal serum 2-4 hours after administration, about 2-μg/ml in amniotic fluid 3 hours, and about 2.7 μg/ml in maternal milk 2 hours. PPA was not detected in fetal tissues.
3. PPA was administered to 11 cases of infections at daily doses of 750-1, 000 mg for 5-45 days with favorable results in 7 cases (efficacy rate : 63.6%).
4. Side effects were not observed at all.
