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Lomustine (CCNU)

Prescription
Nitrosourea Alkylating Agent (Chemotherapy)
Last reviewed 21 Apr 2026 · PetCare.AI Editorial Team
Species
Dog, Cat
Brands
2 available
Interactions
1 documented
Formulations
1

Mechanism of action

Lipophilic nitrosourea that alkylates and crosslinks DNA strands, and carbamylates proteins. Excellent CNS penetration due to lipid solubility. Cell-cycle non-specific.

At a glance

Class
Nitrosourea Alkylating Agent (Chemotherapy)
Schedule
Prescription (Chemotherapy)
Storage
Store at room temperature 15–30°C; handle with gloves (chemotherapy)

Dosing

🐕

Dog

Used for lymphoma, mast cell tumors, brain tumors, histiocytic sarcoma
Dose
60–90 mg/m²
Route
PO
Frequency
q3–6 weeks
🐈

Cat

Used for lymphoma, mast cell tumors, feline injection-site sarcomas
Dose
40–60 mg/m²
Route
PO
Frequency
q3–6 weeks

Formulations

💊

Other — 1

Strength
—

Storage

Store at room temperature 15–30°C; handle with gloves (chemotherapy)

Safety

Monitoring parameters

CBC at nadir and before each doseHepatic enzymes (ALT, ALP) before each doseRenal function

Interactions

Major — 1

Phenobarbital
major
Both are hepatotoxic. Phenobarbital causes chronic hepatic enzyme elevation; lomustine causes cumulative hepatotoxicity. Combined: significantly increased risk of fatal hepatic failure.
Management: Monitor hepatic enzymes before every lomustine dose. Consider hepatoprotectants (SAMe, silymarin). If ALT >3x baseline, withhold lomustine. Consider alternative anticonvulsant (levetiracetam — not hepatotoxic).

Brands

Other markets

CeeNU
Gleostine

FAQs

Frequently asked questions

›What is Lomustine (CCNU)?
Lomustine (CCNU) is a nitrosourea alkylating agent (chemotherapy) used in pets. Lipophilic nitrosourea that alkylates and crosslinks DNA strands, and carbamylates proteins. Excellent CNS penetration due to lipid solubility. Cell-cycle non-specific.
›What is Lomustine (CCNU) used for in pets?
Lomustine (CCNU) is used in veterinary medicine for: Used for lymphoma, mast cell tumors, brain tumors, histiocytic sarcoma; Used for lymphoma, mast cell tumors, feline injection-site sarcomas.
›What is the Lomustine (CCNU) dose for dogs?
For dogs, Lomustine (CCNU) is typically dosed as follows — Used for lymphoma, mast cell tumors, brain tumors, histiocytic sarcoma: 60–90 mg/m² PO q3–6 weeks. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›What is the Lomustine (CCNU) dose for cats?
For cats, Lomustine (CCNU) is typically dosed as follows — Used for lymphoma, mast cell tumors, feline injection-site sarcomas: 40–60 mg/m² PO q3–6 weeks. Always consult your veterinarian for a dose tailored to your pet's weight, age, and condition.
›Does Lomustine (CCNU) need a prescription?
Yes. Lomustine (CCNU) is a prescription medication and should only be administered under veterinary supervision.

References

References

Textbooks & handbooks

  • Plumb, D.C. Plumb's Veterinary Drug Handbook. 10th ed., Wiley-Blackwell, 2023.
  • Vail, D.M., Thamm, D.H., & Liptak, J.M. (eds.). Withrow & MacEwen's Small Animal Clinical Oncology. 6th ed., Saunders/Elsevier, 2020.
  • Riviere, J.E., & Papich, M.G. (eds.). Veterinary Pharmacology and Therapeutics. 10th ed., Wiley-Blackwell, 2018.
  • National Research Council. Nutrient Requirements of Dogs and Cats. National Academies Press, Washington DC, 2006.
  • The Merck Veterinary Manual. Merck & Co., Online edition. https://www.merckvetmanual.com/

Clinical guidelines & consensus

  • Fletcher, D.J., Boller, M., Brainard, B.M., et al. "RECOVER Evidence and Knowledge Gap Analysis on Veterinary CPR." Journal of Veterinary Emergency and Critical Care, 2012;22(S1):S102–S131.
  • American Animal Hospital Association. 2018 AAHA Diabetes Management Guidelines for Dogs and Cats. AAHA Press.

Journals & peer-reviewed studies

  • Hogan, D.F., Fox, P.R., Jacob, K., et al. "Secondary prevention of cardiogenic arterial thromboembolism in the cat: The FAT CAT study." Journal of Veterinary Cardiology, 2015;17(Suppl 1):S306–S317.
  • Boswood, A., Häggström, J., Gordon, S.G., et al. "Effect of Pimobendan in Dogs with Preclinical Myxomatous Mitral Valve Disease and Cardiomegaly: The EPIC Study — A Randomized Clinical Trial." Journal of Veterinary Internal Medicine, 2016;30(6):1765–1779.
  • ASPCA Animal Poison Control Center. Toxicology and Poison Management Guidelines. American Society for the Prevention of Cruelty to Animals. https://www.aspca.org/pet-care/animal-poison-control

Regulatory & approvals

  • Central Drugs Standard Control Organisation (CDSCO), Government of India. Veterinary Drug Approval Registry, 1969–2026. Directorate General of Health Services. https://cdsco.gov.in/

Databases

  • Washington State University, College of Veterinary Medicine. Veterinary Clinical Pharmacology Laboratory (VCPL) — MDR1 Multidrug Sensitivity Database. https://vcpl.vetmed.wsu.edu/
Educational reference only
This information is provided for educational purposes and is not a substitute for professional veterinary advice, diagnosis, or treatment. Always consult a qualified veterinarian before administering any medication to your pet. Find a vet near you →

Related medicines

Other medicines in the same class (Nitrosourea Alkylating Agent).

Streptozocin
Rx
Naturally occurring nitrosourea antibiotic from Streptomyces achromogenes that alkylates DNA and selectively destroys pancreatic beta cells (used therapeutically for insulinoma). Also inhibits DNA synthesis via carbamylation.
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