Lomustine (or CCNU) is classified as a nitrosurea antitumor alkylating agent. It is used in the veterinary field to treat mast cell tumors and lymphosarcoma.

How Does Lomustine Work?

Lomustine bonds with the DNA of rapidly dividing cancer cells, causing genetic defects in the cells and ultimately resulting in the death of the cancer cells. Since malignant cancer cells are among the fastest dividing cells in the body, the drug focuses on those cells. Of course, other rapidly dividing cells in the body can also be affected, like those found in the hair and the gastrointestinal lining, which is the primary cause for the side effects associated with this treatment.

Possible Side Effects of Lomustine

Lomustine is a very potent anti-cancer drug and therefore, it may cause some patients to experience side effects such as hair loss, nausea, vomiting, diarrhea and loss of appetite. In rare cases, more severe side effects may present themselves. These include anemia, bone marrow suppression and the development of lymphoid tissue.

Lomustine Precautions

Lomustine should be avoided in patients with a known allergy to the medication. In some cases, it can be used if the patient has pre-existing kidney disease or liver disease, but it should be administered with extreme caution, since the drug itself can cause kidney or liver damage.

If the animal patient is currently taking other medications, the drugs should be revealed to the veterinarian so a potential drug interaction doesn’t not occur. This is important because lomustine may interact with certain drugs, including amphotericin B, chloramphenicol, cyclophosphamide and azathioprine.

How Is Lomustine Administered?

Lomustine is only available in an oral formulation, the strength of which depends on the animal under treatment and the condition in question. When an animal is prescribed lomustine, it is important to follow the veterinary directions, to monitor the patient as recommended, and to finish the complete course of treatment, unless otherwise directed by the veterinarian.