Lomustine is a nitrosourea alkylating agent used primarily in the treatment of certain brain tumors and Hodgkin's lymphoma. It is a cell cycle-non-specific antineoplastic agent that crosses the blood-brain barrier, making it particularly valuable for central nervous system malignancies. In India, it is a critical component of chemotherapy regimens for refractory cancers.
Adult: 130 mg/m² as a single oral dose every 6 weeks. Dosage adjustments are made based on nadir blood counts from prior cycle. For patients with compromised bone marrow function, the initial dose is often reduced to 100 mg/m² every 6 weeks.
Note: Administer orally as a single dose on an empty stomach (at least 2 hours after and 2 hours before a meal) to minimize nausea/vomiting. Capsules should be swallowed whole with water. Do not crush or break capsules due to carcinogenic risk. Dosing interval is typically every 6 weeks, pending recovery of blood counts.
Lomustine exerts its cytotoxic effects through alkylation and carbamoylation. It cross-links DNA and RNA strands, inhibiting DNA replication and transcription. It also carbamoylates proteins, interfering with DNA repair processes and RNA production.
Pregnancy: FDA Pregnancy Category D. Lomustine is teratogenic and embryotoxic. Can cause fetal harm. Contraindicated in pregnancy. Women of childbearing potential must use effective contraception during and for at least 6 months after therapy.
Driving: May cause dizziness, lethargy, or disorientation. Patients should be cautioned against driving or operating machinery, especially shortly after dosing.
| Cimetidine | Increased myelosuppression due to potential inhibition of lomustine metabolism. | Major |
| Phenobarbital, Phenytoin | May increase metabolism of lomustine, potentially reducing efficacy. | Moderate |
| Other Myelosuppressive Agents (e.g., Cyclophosphamide, Azathioprine) | Additive bone marrow toxicity. Requires careful monitoring and dose adjustment. | Major |
| Live Vaccines (e.g., MMR, Varicella) | Risk of disseminated infection due to immunosuppression. Contraindicated. | Major |
| Digoxin | Lomustine may reduce absorption of digoxin. | Moderate |