Lomustine

Lomustine, also known as CCNU and marketed as CeeNU in some regions, is an oral chemotherapy agent classified as a nitrosourea alkylating compound. It is lipophilic and crosses the blood–brain barrier, enabling activity against certain central nervous system tumors as well as systemic cancers.

Its mechanism of action involves alkylation of DNA and RNA, leading to cross-links that disrupt replication and transcription and ultimately cause tumor cell death. The prolonged tissue half-life of lomustine contributes to sustained anticancer effects but also to extended toxicity.

In humans, lomustine is used for selected brain tumors, including glioblastoma multiforme and anaplastic astrocytoma, and has been employed for other cancers in some settings. In veterinary medicine, lomustine is commonly used in the treatment of canine lymphomas and mast cell tumors, as well as other cancers in which conventional therapies are unsuitable or ineffective.

Lomustine is administered by mouth as capsules. Dosing is typically based on body weight or surface area and is given in cycles spaced several weeks apart to allow bone marrow recovery. Because of potential liver toxicity and bone marrow suppression, patients are closely monitored with blood counts and liver enzyme tests during and after treatment.

Common adverse effects include bone marrow suppression (which can raise infection risk and cause low blood counts), hepatotoxicity, vomiting, diarrhea, and reduced appetite. Caution is advised during pregnancy, lactation, or when used concomitantly with other myelosuppressive therapies.