The nitrosoureas carmustine and lomustine are alkylating agents that crosslink DNA after being bioactivated by P450 enzymes in the liver. These drugs have a unique ability to cross the blood-brain barrier, making them useful for treating brain tumors, but this ability can also lead to CNS toxicity in patients taking these medications. 

Key Points

  • Nitrosoureas
    • Drugs
      • Carmustine
      • Lomustine
    • Mechanism
      • Crosslinks DNA
        • Requires bioactivation by liver (P450)
        • Crosses blood-brain barrier (BBB) into the CNS
    • Clinical Use
      • Brain tumors
        • Because it crosses BBB
        • Including glioblastoma multiforme 
    • Adverse Effects
      • CNS toxicity
        • Symptoms including ataxia, convulsions, dizziness