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. |
Pharmacodynamics |
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. |
Absorption |
Well and rapidly absorbed from the gastrointestinal tract. |
Volume of distribution |
Not Available |
Protein binding |
50% |
Metabolism |
Hepatic. Rapid and complete, with active metabolites. |
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. |
Half life |
Approximately 94 minutes, however the metabolites have a serum half-life of 16 to 48 hours. |
Clearance |
Not Available |
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. |