The pharmacology of fenbufen, 3-(4-biphenylylcarbonyl)propionic acid, and 4-biphenylacetic acid, interesting antiinflammatory-analgesic agents.

Fenbufen [3-(4-biphenylylcarbonyl)propionic acid] was shown to be an orally and parenterally effective nonsteroidal antiinflammatory analgetic and antipyretic agent in animals. Like clinically useful drugs (aspirin, phenylbutazine and indomethacin) it has potent antiinflammatory activity in a wide spectrum of laboratory tests in mice, rats, guinea pigs, and dogs and was of particular interest since it appears to have high analgetic efficacy and a long duration of antiinflammatory and analgetic action. While shown to have ulcerogenic potential in rats at toxic doses, it appeared to have a superior margin of gastrointestinal safety in treatment of dogs with urate synovitis. Evidence was also presented to show that BPAA (4-biphenylacetic acid), a metabolite of fenbufen, has a similar profile of antiinflammatory activity, although appearing to produce slightly more gastrointestinal injury. It appears that BPAA may be the agent responsible for at least part of fenbufen's pharmacologic effects. The data presented suggest that fenbufen has the potential to be used safely and effectively to provide relief for patients with inflammatory disease.