Pipemidic acid is a member of the pyridopyrimidine class of antibacterials, which display some overlap in mechanism of action with analogous pyridone-containing quinolones. It was introduced in 1979 and is active against gram negative and some gram positive bacteria. It was used for gastrointestinal, biliary, and urinary infections.[1] The marketing authorization of pipemidic acid has been suspended throughout the EU.[2]