Peripheral Blood Toxicity of Topical 5-Fluorouracil on the Syrian Hamster Cheek Pouch

¹ Division of Biological Dental Sciences, Section of Oral Diagnosis, Medicine, Pathology, and Dental Research Institute, School of Dentistry, the Center for the Health Sciences, University of California, Los Angeles, California 90024, USA

Toxicological studies on the peripheral blood after topical application of 5-fluorouracil to the buccal pouch of the Syrian hamster showed that a daily application of 10 µl (0.5 mg) was the maximum ideal dose for this animal. This dose did not depress to a significant degree the white blood cell count, red blood cell count, hemoglobin level, hematocrit value, or the peripheral differential blood counts after 14 daily applications. Doses of increased concentration either daily or periodically were less effective and toxic.