ABSTRACT
There are two main limiting factors for successful chemotherapy,
namely (a) development of chemo-resistance and (b) toxic effects of
chemo drugs to normal tissues.
Modulating agents are used to improve the therapeutic index of
chemotherapy. They can be divided into three main classes:
(a) agents that protect host tissue from a toxic effect of chemo drugs
(b) agents that potentiate anti-cancer drugs
(c) agents that reverse acquired drug resistance
Folinic acid is the reduced form of folic acid. It can readily be
converted to tetrahydrofolate, which does not require an action
of dihydrofolate reductase. Tetrahydrofolate has vitamin activity
equivalent to folic acid. Methotrexate (MTX) inhibits dihydrofolate
reductase.
