While observing in the oncology clinic, a student nurse is reviewing chemotherapy orders for a client with advanced colorectal cancer. The nurse providing care explains the client is to receive "high dose methotrexate with leucovorin rescue." The student understands the leucovorin calcium is given for which of the following reasons?
A) As a catalyst to increase the number of cancer cells destroyed by the methotrexate.
B) As an antidote to the methotrexate to reduce the destruction of blood cells.
C) As a second chemotherapeutic agent that will destroy cancer cells using a different mechanism.
D) As a carrying agent to ensure delivery of the methotrexate into the cells.

Question

Quizplus · Accepted Answer

Leucovorin calcium is given as a rescue therapy to reduce the toxic effects of methotrexate on the normal cells of the body. Methotrexate is a folate antagonist and it inhibits the folate-dependent enzymes responsible for the synthesis of DNA and RNA needed for the growth and division of cells. Leucovorin is a reduced form of folic acid that rescues normal cells from the toxic effects of methotrexate by acting as a replacement for the lost folate. This allows cells to continue to grow and divide normally, while still allowing methotrexate to target the cancer cells.

While Observing in the Oncology Clinic, a Student Nurse Is