Lomustine
Also known as: CeeNu, Belustine, Cecenu, CiNU, Citosta, Lomeblastin, Lucostin, Lucostine, Prava, CCNU, Gleostine, CeeNU
**Important Safety and Handling Guidelines:** * **Cytotoxic Precautions:** Lomustine is a chemotherapy drug. Wear disposable gloves when handling the capsules. **Do not open, crush, or split the capsules.** * **Waste Management:** The drug and its toxic metabolites can be detected in the pet's urine and feces for up to 24 hours (some protocols recommend precautions for 48-72 hours) after a dose. Wear gloves when cleaning up urine, feces, or vomit, and wash hands thoroughly afterward. Pregnant women or immunosuppressed individuals should avoid handling the drug or the pet's waste. **When to Contact the Veterinarian:** * Lomustine can cause severe suppression of the bone marrow and liver damage. * Contact your veterinarian **immediately** if your pet develops signs of infection, runs a fever, exhibits unusual bruising or bleeding, has yellowing of the whites of the eyes or gums (jaundice), experiences persistent vomiting, diarrhea, or simply becomes lethargic and ill.
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 (CNS neoplasms, lymphomas, mast cell tumors)
- Antineoplastic (CNS neoplasms, lymphomas, mast cell tumors)
- All uses
- Antineoplastic (CNS neoplasms, lymphomas, mast cell tumors, histiocytic sarcomas)
- All uses (brain tumours, mast cell tumours, lymphoma, histiocytic sarcoma)
How it is given
Possible side effects
- Bone marrow depression (anemia, thrombocytopenia, leukopenia) - nadirs typically at 1-6 weeks
- Hepatotoxicity (delayed, cumulative, chronic, and irreversible in dogs)
- Anorexia
- Vomiting
- Diarrhea
- Stomatitis
- Alopecia
- Corneal de-epithelization
- Renal toxicity (rare)
- Pulmonary infiltrates or fibrosis (rare)
- Myelosuppression (dose-limiting; severe neutropenia and thrombocytopenia)
- Hepatotoxicity (cumulative, dose-related, potentially irreversible in dogs)
- Gastrointestinal toxicity (vomiting, diarrhea, anorexia)
Cautions & contraindications
- Pre-existing severe bone marrow depression
- Active infections
- Pregnancy (Teratogenic - FDA Category D)
- Nursing/lactating animals
- Pre-existing bone marrow suppression
- Pre-existing liver disease
- Pregnancy and lactation
- Use only when potential benefits outweigh risks in patients with pre-existing anemia, bone marrow depression, pulmonary function impairment, current infection, impaired renal function, or sensitivity to lomustine. Extreme caution is required in patients who have received previous chemotherapy or radiotherapy due to compromised bone marrow reserves. **Hepatotoxicity** in dogs can be severe, delayed, and irreversible. **Teratogenic** in laboratory animals; suppresses gonadal function. Nursing puppies/kittens should receive milk replacer if the mother is treated.
Drug interactions
- Immunosuppressive drugs (e.g., azathioprine, cyclophosphamide, corticosteroids): May increase the risk of severe infection due to additive immunosuppression.
- Myelosuppressive drugs (e.g., chloramphenicol, flucytosine, amphotericin B, colchicine): Additive bone marrow depression; concurrent use should be avoided or strictly monitored.
- Live virus vaccines: Increased risk of vaccine-induced infection or decreased vaccine efficacy; use with extreme caution or avoid during therapy.
- Other myelosuppressive agents: Increased risk of severe and potentially fatal bone marrow suppression.
- Phenobarbital (and other liver enzyme inducers): Altered metabolism of lomustine, which requires hepatic microsomal enzyme hydroxylation. Use with caution.
- Cimetidine: Enhances the toxicity of lomustine (reported in humans).
Frequently asked questions
What is Lomustine used for in pets?
**Important Safety and Handling Guidelines:** * **Cytotoxic Precautions:** Lomustine is a chemotherapy drug. Wear disposable gloves when handling the capsules. **Do not open, crush, or split the capsules.** * **Waste Management:** The drug and its toxic metabolites can be detected in the pet's urine and feces for up to 24 hours (some protocols recommend precautions for 48-72 hours) after a dose. Wear gloves when cleaning up urine, feces, or vomit, and wash hands thoroughly afterward. Pregnant women or immunosuppressed individuals should avoid handling the drug or the pet's waste. **When to Contact the Veterinarian:** * Lomustine can cause severe suppression of the bone marrow and liver damage. * Contact your veterinarian **immediately** if your pet develops signs of infection, runs a fever, exhibits unusual bruising or bleeding, has yellowing of the whites of the eyes or gums (jaundice), experiences persistent vomiting, diarrhea, or simply becomes lethargic and ill.
Is Lomustine 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.
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