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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

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

Frequency

q3–6 weeks

🐈

Cat

Used for lymphoma, mast cell tumors, feline injection-site sarcomas

Dose

40–60 mg/m²

Route

Frequency

q3–6 weeks

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 →

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

Educational reference only

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).

Educational reference only

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.

Educational reference only

References

The PetCare.AI drug reference is built from 13 authoritative sources cited across 580 drug monographs.

Textbooks & handbooks — 5

Plumb's Veterinary Drug Handbook
Withrow & MacEwen's Small Animal Clinical Oncology
Merck Veterinary Manual
NRC Nutrient Requirements of Dogs and Cats
Veterinary Pharmacology and Therapeutics (Riviere & Papich)

Clinical guidelines & consensus — 4

ASPCA Animal Poison Control Center Guidelines
AAHA Diabetes Management Guidelines
ASPCA Poison Control Guidelines
RECOVER CPR Guidelines

Journals & peer-reviewed studies — 2

EPIC Study (J Vet Intern Med 2016)
JVIM FAT CAT Study

Regulatory & approvals — 1

CDSCO Veterinary Drug Approval Registry (1969–2026)

Databases — 1

Washington State University VCPL MDR1 Database

Related medicines

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

Streptozocin

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.

dogcat