A comparison of toxicity of two dosing schemes for doxorubicin in the cat

• Published in: Journal of feline medicine and surgery 2008-08, Vol.10 (4), p.324-331
• Main Authors: Reiman, Rachel A., Mauldin, Glenna E., Neal Mauldin, Guy
• Format: Article
• Language: English
• Subjects: Animals; Anorexia - chemically induced; Anorexia - veterinary; Antibiotics, Antineoplastic - adverse effects; Antibiotics, Antineoplastic - therapeutic use; Antibiotics, Antineoplastic - toxicity; Cat Diseases - chemically induced; Cat Diseases - drug therapy; Cats; dose response; Dose-Response Relationship, Drug; doxorubicin; Doxorubicin - adverse effects; Doxorubicin - therapeutic use; Doxorubicin - toxicity; drug toxicity; Female; Kidney - drug effects; Kidney - pathology; Male; Neoplasms - drug therapy; Neoplasms - veterinary; Neutrophils - immunology; Weight Loss - drug effects
• ISSN: 1098-612X; 1532-2750
• DOI: 10.1016/j.jfms.2007.12.009

Doxorubicin is a commonly used and effective treatment for a variety of tumors in both people and cats. However, the use of this drug in cats has been associated with side effects such as renal injury, myelosuppression, anorexia, and weight loss. The goal of this study was to compare the toxicities associated with two dosing schemes for doxorubicin in tumor-bearing cats. Group A cats received 1 mg/kg of doxorubicin, while group B cats received 25 mg/m 2 of doxorubicin plus 22 ml lactated Ringer's solution per kilogram body weight subcutaneously. Toxicities were evaluated using laboratory data, physical examination, and history, and were graded using a standardized scale and compared between groups. Post-treatment neutrophil counts were significantly lower among cats in group B compared to cats in group A ( P ≤ 0.001), although complete blood counts were not evaluated at identical intervals in all cases. No other significant differences in the type, frequency or severity of clinical or laboratory toxicities were noted between groups, and no episodes of sepsis were recognized in either group. The results of this study suggest that higher doses of doxorubicin may not be associated with an increased risk of toxicity in the cat. Additional studies are still indicated to determine optimal dosing for doxorubicin in this species.