Leucovorin rescue is related to:

Methotrexate (MTX) inhibits dihydrofolate reductase, resulting in a decreased supply of folates. In high doses, MTX inhibits purine and pyrimidine synthesis, rendering it useful for many malignancies. In low doses (< 20 mg/week), MTX is commonly used as a disease-modifying antirheumatic drug and is indicated for treatment of rheumatoid ahritis (RA).MTX&;s mechanism of action for this indication is unclear. Efficacy of low-dose MTX may ultimately be the result of anti-inflammatory, immunosuppressant, or immunotoxic effects. Leucovorin is a form of folic acid. Folic acid helps your body produce and maintain new cells, and also helps prevent changes to DNA that may lead to cancer. Folic acid is present in many foods such as dried beans, peas, oranges, spinach, and others. Leucovorin is used to reduce the side effects of large doses or accidental overdose of medications that can reduce the effects of folic acid in the body. This includes methotrexate (Rheumatrex), pyrimethamine (Daraprim), trimethoprim (Trimpex, Proloprim), and others. REFERENCE: www.drugs.com, www.medscape.com,