Just Ask the Expert: Transitional cell carcinoma of the bladder and piroxicam
Dr. Fan welcomes oncology questions from veterinarians and veterinary technicians.
Q: Does piroxicam have any effect in cats with transitional cell carcinoma of the bladder? If so, what is the recommended dosage?
A. Piroxicam is a mixed COX-1/COX-2 inhibitor that reduces the production of various inflammatory lipid mediators. Such lipid mediators, including prostaglandin E2, may favor the development and growth of tumors through various mechanisms, including the promotion of new blood vessel growth, immunosuppression, and reduced death signaling. Because of these effects, piroxicam has demonstrated modest activity in dogs with transitional cell carcinoma.1
The potential anticancer effects of piroxicam in cats with transitional cell carcinoma have not been thoroughly described,2 but, anecdotally, piroxicam appears to be well-tolerated at a dosage of 0.3 mg/kg by mouth two or three times a week.2 Using this dosing scheme in cats with transitional cell carcinoma should be safe based on prior pharmacokinetic studies of oral piroxicam conducted in healthy cats3,4; however, its anticancer effectiveness remains poorly characterized in cancer-bearing cats.
Timothy M. Fan, DVM, PhD, DACVIM (internal medicine and oncology)
The intent of Just Ask the Expert is to address non-urgent medical questions and to share this information through the Web site with other practitioners. The recommendations are for informational purposes only. It is each clinician’s responsibility to carefully weigh these recommendations and determine the right course of action for each patient. Please verify any drug dosages discussed. Questions may be edited for style and length.