indication

For the treatment of primary and metastatic brain tumors as a component of combination chemotherapy in addition to appropriate surgical and/or radiotherapeutic procedures. Also used in combination with other agents as secondary therapy for the treatment of refractory or relapsed Hodgkin's disease.

pharmacology

Lomustine is an alkylating agent of the nitrosourea type. Lomustine and its metabolites interferes with the function of DNA and RNA. It is cell cycle–phase nonspecific. Cancers form when some cells within the body multiply uncontrollably and abnormally. These cells then spread and destroy nearby tissues. Lomustine acts by slowing this process down. It kills cancer cells by damaging the DNA (the genetic material inside the cells) and stops them from dividing.

mechanism of action

Lomustine is a highly lipophilic nitrosourea compound which undergoes hydrolysis in vivo to form reactive metabolites. These metabolites cause alkylation and cross-linking of DNA (at the O6 position of guanine-containing bases) and RNA, thus inducing cytotoxicity. Other biologic effects include inhibition of DNA synthesis and some cell cycle phase specificity. Nitrosureas generally lack cross-resistance with other alkylating agents. As lomustine is a nitrosurea, it may also inhibit several key processes such as carbamoylation and modification of cellular proteins.

toxicity

Oral, rat: LD₅₀ = 70 mg/kg. Pulmonary toxicity has been reported at cumulative doses usually greater than 1,100 mg/m2. There is one report of pulmonary toxicity at a cumulative dose of only 600 mg. The onset of toxicity has varied from 6 months after initiation of therapy, to as late as 15 years after.

biotransformation

Hepatic. Rapid and complete, with active metabolites.

absorption

Well and rapidly absorbed from the gastrointestinal tract.

half life

Approximately 94 minutes, however the metabolites have a serum half-life of 16 to 48 hours.

route of elimination

Following oral administration of radioactive CeeNU at doses ranging from 30 mg/m2 to 100 mg/m2, about half of the radioactivity given was excreted in the urine in the form of degradation products within 24 hours.

drug interactions

Atomoxetine: The CYP2D6 inhibitor could increase the effect and toxicity of atomoxetine

Terbinafine: Terbinafine may reduce the metabolism and clearance of Lomustine. Consider alternate therapy or monitor for therapeutic/adverse effects of Lomustine if Terbinafine is initiated, discontinued or dose changed.

Trastuzumab: Trastuzumab may increase the risk of neutropenia and anemia. Monitor closely for signs and symptoms of adverse events.