Methotrexate is a folate antagonist. It inhibits enzymes required for DNA base synthesis. To prevent harm to normal cells, a fully activated form of folic acid known as leucovorin (folinic acid; citrovorum factor) can be administered. Administration of leucovorin is known as:
A. Induction therapy.
B. Consolidation therapy.
C. Pulse therapy.
D. Rescue therapy.
Correct Answer: B. Consolidation therapy.
Leucovorin is used to save or “rescue” normal cells from the damaging effects of chemotherapy allowing them to survive while the cancer cells die. Therapy to rapidly reduce the number of cancerous cells is the induction phase. Consolidation therapy seeks to complete or extend the initial remission and often uses a different combination of drugs than that used for induction.
Option A: The first treatment given for a disease. It is often part of a standard set of treatments, such as surgery followed by chemotherapy and radiation. When used by itself, induction therapy is the one accepted as the best treatment. If it doesn’t cure the disease or it causes severe side effects, other treatment may be added or used instead. Also called first-line therapy, primary therapy, and primary treatment.
Option C: Chemotherapy is often administered in intermittent courses called pulse therapy. Pulse therapy allows the bone marrow to recover function before another course of chemotherapy is given. Pulse therapy means the administration of large (supra pharmacologic) doses of drugs in an intermittent manner to enhance the therapeutic effects and reduce the side-effects.
Option D: Salvage therapy, also known as rescue therapy, is a form of therapy given after an ailment does not respond to standard therapy. The most common diseases that require salvage therapy are HIV and various cancers. The term is not clearly defined; it is used both to mean a second attempt and a final attempt.