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Toxicologic effects of ribavirin in cats
R C Weiss1, N R Cox, M K Boudreaux
1Scott-Richey Research Center, AL.
Journal of Veterinary Pharmacology and Therapeutics
|September 1, 1993
Summary
Ribavirin, an antiviral drug, caused significant bone marrow toxicity in cats, particularly affecting platelet production. Higher doses also led to reduced white blood cell counts and other adverse effects, limiting its use in feline medicine.
Area of Science:
- Veterinary Pharmacology
- Toxicology
- Antiviral Research
Background:
- Ribavirin is a broad-spectrum antiviral agent used for severe human viral infections.
- Its efficacy and safety in cats, a common companion animal, are not well-established.
- Previous studies indicate potential toxicity in laboratory animals and humans.
Purpose of the Study:
- To evaluate the feasibility and safety of using ribavirin in cats.
- To determine the effects of oral, intramuscular, and intravenous ribavirin doses on feline health.
- To assess dose-related toxicity and identify target organs in cats.
Main Methods:
- Twenty-seven 9-month-old specific-pathogen-free cats received daily oral, intramuscular, or intravenous ribavirin (11, 22, or 44 mg/kg) for 10 days.
- Evaluations included hematology, clinical chemistries, bone marrow biopsies, and histopathology.
- Cats were euthanized and necropsied post-treatment.
Main Results:
- Thrombocytopenia (reduced platelet count) was the most significant hematologic change, occurring in a dose-dependent manner.
- Anorexia, weight loss, diarrhea, and mucous membrane pallor were observed at higher doses (22 and 44 mg/kg).
- Bone marrow analysis revealed dose-related megakaryocytic hypoplasia and dysplasia, with more severe effects at higher doses.
Conclusions:
- Daily ribavirin administration in cats induces dose-related bone marrow toxicity, primarily affecting megakaryocytes and erythroid precursors.
- Higher dosages also suppressed circulating leukocytes and caused clinical signs like anorexia and weight loss.
- These findings suggest significant safety concerns for ribavirin use in cats, especially at therapeutic doses.
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