Dactinomycin
Also known as: Cosmegen, Lyovac
Dactinomycin is a potent chemotherapy drug used to treat certain cancers. Because it is very strong, it requires careful monitoring. * **Toxicity Signs:** Contact your veterinarian *immediately* if your pet shows signs of serious illness, including bloody vomiting or diarrhea, abnormal bleeding or bruising, straining to urinate, severe lethargy/depression, signs of infection (fever), or shortness of breath. * **Oral Sores:** Check your pet's mouth periodically for sores or ulcers, which can make eating painful. * **Safety at Home:** Because this drug is eliminated in your pet's waste and has the potential to cause cell damage, wear gloves when handling your pet's urine, feces, or vomit for a few days after treatment. Wash your hands thoroughly afterward. * **Breeding/Pregnancy:** This drug can cause birth defects. Do not breed pets receiving this medication.
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
What it is used for
- Antineoplastic protocols (e.g., rescue therapy for lymphomas, sarcomas)
- Lymphoma (rescue protocols), sarcomas, and carcinomas
How it is given
Possible side effects
- Bone marrow depression (anemia, leukopenia, thrombocytopenia)
- Gastrointestinal toxicity (diarrhea, ulcerative stomatitis, GI ulceration)
- Severe tissue damage and pain (if extravasated)
- Hyperuricemia (may require allopurinol)
- Hepatotoxicity
Cautions & contraindications
- Hypersensitivity to dactinomycin
- Pregnancy (teratogenic and embryotoxic)
- **WARNING: Severe Vesicant and Highly Toxic** * **Extravasation Risk:** Can cause extensive pain and tissue damage. Must be administered via a perfectly placed IV catheter, ideally using a 'two-needle' technique and slow infusion into a running IV line. * **MDR1 Mutation:** Use with extreme caution or avoid in breeds susceptible to the MDR1-allele mutation (Collies, Australian Shepherds, Shelties, Long-haired Whippets) due to high risk of fatal toxicity. * **Organ Dysfunction:** Use with caution in patients with preexisting bone marrow depression, hepatic dysfunction, or active infections. * **Hazardous Drug:** Chronic exposure increases mutagenic, teratogenic, and carcinogenic risks for healthcare workers. Strict hazardous drug handling, preparation, and disposal protocols are required. * **Pregnancy/Nursing:** Embryotoxic and teratogenic (FDA Category C). Avoid use in pregnant or nursing animals.
Drug interactions
- Doxorubicin: Additive cardiotoxicity may occur if used concurrently or sequentially.
- Myelosuppressive drugs (e.g., chloramphenicol, flucytosine, colchicine, other antineoplastics): May cause additive myelosuppression.
- Vitamin K: Patients may require higher dosages of vitamin K when receiving dactinomycin.
Frequently asked questions
What is Dactinomycin used for in pets?
Dactinomycin is a potent chemotherapy drug used to treat certain cancers. Because it is very strong, it requires careful monitoring. * **Toxicity Signs:** Contact your veterinarian *immediately* if your pet shows signs of serious illness, including bloody vomiting or diarrhea, abnormal bleeding or bruising, straining to urinate, severe lethargy/depression, signs of infection (fever), or shortness of breath. * **Oral Sores:** Check your pet's mouth periodically for sores or ulcers, which can make eating painful. * **Safety at Home:** Because this drug is eliminated in your pet's waste and has the potential to cause cell damage, wear gloves when handling your pet's urine, feces, or vomit for a few days after treatment. Wash your hands thoroughly afterward. * **Breeding/Pregnancy:** This drug can cause birth defects. Do not breed pets receiving this medication.
Is Dactinomycin safe for my pet?
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
This article is for general education and is not a substitute for professional veterinary advice. If your pet is unwell, please consult a veterinarian.
Worried about your pet?
Peqaboo’s AI helps you track symptoms, understand lab reports, and know when to see a vet.
Get the Peqaboo app