FIP & Propentofylline

Anecdotal reports have described the use of the methylxanthine derivative pentoxifylline (PTX) as a palliative therapy for cats with feline infectious peritonitis (FIP). While PTX did not cure the disease, it reportedly improved quality of life, possibly by decreasing vasculitis. In this placebo-controlled double-blind study, investigators used propentofylline (PPF), another methylxanthine derivative similar to PTX, for the treatment of 23 pet cats diagnosed with FIP.

Cats were randomly assigned to either the treatment group (n = 7) or placebo group (n = 16). Patients also received low-molecular-weight heparin to minimize the risk for disseminated intravascular coagulation, as well as glucocorticoids, antibiotics, and nutritional support. Tumor necrosis factor-alpha (TNF-α) was measured via ELISA on days 0, 7, 14, and 28. During the first 7 days of the study, cats were examined daily and their general condition characterized by the Karnofsky score for assessing quality of life. There were no significant differences between the 2 groups in the parameters measured, including amount of effusion, Karnofsky score (quality of life), TNF-α, or survival time. Median survival time of treated cats and that of the placebo group was 8 days and 7.5 days, respectively. These results suggest that PPF is not an effective treatment for cats with late-stage FIP.

CommentaryThis article demonstrates the lack of efficacy of PPF for the treatment of FIP. Theoretically, a drug that prevents the viral mechanism of tissue damage would be effective; however, as demonstrated in this study, theory does not always translate into clinical efficacy. Treatments recommended or prescribed based only on anecdotal evidence of efficacy may not only be ineffective but also costly and have adverse effects. More studies are needed; it is important for both novel and currently unevaluated therapies to be prospectively and blindly evaluated to determine safety and clinical efficacy. Only through this method of investigation can we start to truly define the most productive therapies for a given disease.—Jennifer Ginn, DVM, MS, DACVIM

SourceRandomized, placebo controlled study of the effect of propentofylline on survival time and quality of life of cats with feline infectious peritonitis. Fischer Y, Ritz S, Weber K, et al. J VET INTERNMED25:1270-1276, 2011.