Name
- Doxorubicin.
Class of drug
- Cytotoxic anthracycline antibiotic.
Uses
Action
- Binds to DNA and inhibits nucleic acid synthesis.
- Free radical formation.
- Topoisomerase inhibition.
Indications
- Lymphosarcoma , soft tissue sarcomas , hemangiosarcoma , carcinomas (thyroid and mammary) in the dog. Lymphoma, soft tissue sarcomas (including vaccine associated sarcomas) and mammary carcinomas in the cat.
- It may be used alone or in combination with other antineoplastic therapies.
Adverse reactions
Other reported reactions
- Severe vesicant if given perivascularly, therefore should be given through well-placed IV catheter. Damage may be severe enough to require amputation.
- Anorexia, vomiting, severe leukopenia, thrombocytopenia, hemorrhagic gastroenteritis and nephrotoxicity (may occur in cats if cumulative dosages exceed 100 mg/m²).
- Allergic reactions have been reported.
- Dose-dependent cumulative cardiotoxicity in dogs (dilated cardiomyopathy and congestive heart failure ). The risk increases in dogs after a cumulative dose of 240 mg/m².
- Tachycardia and arrhythmias on administration.
Investigation of adverse reaction
- Dogs should be periodically monitored with ECGs and/or echocardiograms.
- A complete CBC and platelet count should be monitored whenever therapy is given. If the neutrophil count drops below 3x10³/dl or if the platelet count drops below 150x10³/dl, treatment should be suspended. Once the counts have stabilized doxorubicin can then be restarted at the same dose.
- If hematological toxicity occurs again, or if gastrointestinal toxicity is recurrent the dose should be reduced to 20 mg/m².
Treatment
Extravasation
- Stop injection, aspirate through needle used for injection. Reported treatment strategies include: application of warm compresses, application of topical DMSO, Dexrazoxane, local injection of corticosteroids and surgical debridement. None of these strategies have proven to be consistently effective.
Acute anaphylactic reaction
- Epinephrine, steroids and fluids.
