Anthony S. Ridolfo

Effects of fenoprofen and aspirin on gastrointestinal microbleeding in man.

The 51Cr‐labeled erythrocyte assay was used to compare the effects of equipotent doses of fenoprofen and aspirin—600 mg.:1 Gm.; 400 mg.:650 mg. Based on the appearance of label in the feces of normal men, we conclude that (1) both fenoprofen and aspirin produced measurable gastrointestinal microbleeding in man and (2) the amount of microbleeding after fenoprofen was significantly less than that after the aspirin preparations used in this study.

Section 2 A profile of the physiological disposition and gastro-intestinal effects of fenoprofen in man

SummaryPharmacodynamic studies have shown that fenoprofen is readily absorbed from the gastro-intestinal tract following oral administration and that the disposition of absorbed fenoprofen does not differ significantly whether given orally or intravenously. Results indicate that fenoprofen is rapidly eliminated, in both children and adults, despite its high degree of protein binding. This is because almost all the drug is converted to metabolites which are readily excreted in urine. The evidence suggests that, at the recommended therapeutic dosages, there is unlikely to be any significant accumulation of fenoprofen or its metabolites with chronic administration. Possible pharmacodynamic interactions between fenoprofen and other drugs, e.g. aspirin and phenobarbital, are discussed, and the evidence is reviewed that at equi-effective doses fenoprofen causes less gastro-intestinal microbleeding than does aspirin.

Screening rapidly acting anti-inflammatory agents in patients with rheumatoid arthritis.

Two screening tests by means of subjective responses of patients with active rheumatoid arthritis are described. In both, daily telephone interviews were used to gather data concerning drug preference or a comfort index. These studies adhered to the requirements for meaningful evaluations of subjective data. In the first study, one drug—aspirin or fenoprofen (dl-2-[3-phenoxyphenyl] propionic acid)-and placebo were compared over a four-day interval. The interpretations of the results of this study were supported by those of the second study in which each medication was given continuously for seven days. The patients preferred aspirin and fenoprofen to placebo, and reported placebo to provide less comfort than either of the other medications.

Tracer microspheres as a fecal marker in balance studies

The use of radio labeled microspheres as fecal markers was investigated and compared in vivo to chromium sesquioxide and β‐sitosterol. They proved to be chemically inert, uniformly distributed in feces, and fully recoverable. The advantages over the other markers include minimal handling of specimen and direct measurement without complex analytic procedures.

Section 2 Clinical experience with fenoprofen, a new antirheumatic agent

SummaryThe authors review the studies which have been carried out on fenoprofen. Fenoprofen has been demonstrated to have anti-inflammatory, analgesic and antipyretic activity in both animals and man. It is an effective and well tolerated agent in the symptomatic treatment of patients with rheumatoid arthritis, degenerative joint disease, ankylosing spondylitis, acute gout and non-articular rheumatism. Fenoprofen is also useful in the symptomatic treatment of a variety of conditions associated with pain and fever.The main adverse reactions have been minor skin rashes and gastro-intestinal disturbances. Although less irritating than aspirin, fenoprofen should be used with caution in patients with a history of peptic ulcer disease. The risk-to-benefit ratio suggests that fenoprofen will be a useful therapeutic agent.