Pipemidic acid: its activities against various experimental infections.

Pipemidic acid, a structural relative of piromidic and nalidixic acids, exhibited substantial therapeutic activity when it was administered orally to mice bearing either widely disseminated or relatively localized infections with Staphylococcus aureus and a variety of gram-negative bacilli. The activity of pipemidic acid was always greater than that of piromidic and nalidixic acids; in infections with Pseudomonas aeruginosa and in bacilli resistant to the latter two drugs, pipemidic acid exhibited significant activity. In limited comparative studies, the activities of pipemidic acid were generally superior to the activities of cephalexin, ampicillin, and carbenicillin. Gentamicin, administered subcutaneously, was more active than pipemidic acid, given either orally or subcutaneously, against both systemic and localized infections with P. aeruginosa. The therapeutic accomplishments of pipemidic acid were attained with well-tolerated doses.