Pharmacological properties : תכונות פרמקולוגיות

Pharmacodynamic Properties

5.1      Pharmacodynamic properties

Pharmacotherapeutic Group: Antineoplastic medicine, alkylating agent, nitrosourea ATC-Code: L01AD01

Carmustine alkylates DNA and RNA, has also been shown to inhibit several enzymesby carbamoylation of amino acids in proteins. It is thought that the antineoplastic andtoxic activities of Carmustine may be due to metabolites.

Pharmacokinetic Properties

5.2      Pharmacokinetic properties
Distribution
Intravenously administered Carmustine is rapidly degraded, with no drug intact detectable after 15 minutes. Because of the good lipid solubility and the lack of ionization at the physiological pH, Carmustine is very well transferred through theblood-brain barrier.
Levels of radioactivity in the CSF are at least 50% higher thanthose measured concurrently in plasma.
The kinetic of carmustine in humans is characterized by a two-chamber model. Afterthe intravenous infusion over 1 hour, the carmustine-plasma level drops in a biphasicmanner. The half life α accounts to 1-4 minutes and the half life β accounts to 18-69 minutes.

Metabolism
It is presumed that the metabolites of carmustine causes its antineoplastic and toxicactivity.

Elimination
Approximately 60-70% of a total dose is excreted in the urine in 96 hours and about10% as respiratory CO2. The fate of remainder is undetermined.