Per the National Institutes of Medicine:
Leucovorin Calcium (loo koe vor' in) is in a class of medications called folic acid analogs. It works by protecting healthy cells from the effects of chemotherapy medications while allowing them to enter and kill cancer cells.
Before taking leucovorin:
- Tell your doctor and pharmacist if you are allergic to leucovorin, levoleucovorin, folic acid (Folicet, in multivitamins), any other medications, or any of the ingredients in leucovorin tablets. Ask your pharmacist for a list of the ingredients.
- Tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: certain medications for seizures such as phenobarbital, phenytoin (Dilantin), and primidone (Mysoline); and trimethoprim-sulfamethoxazole (Bactrim, Septra). Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
- Tell your doctor if you have anemia (low number of red blood cells) caused by lack of vitamin B12 or inability to absorb vitamin B12. Your doctor will not prescribe leucovorin to treat this type of anemia.
- Tell your doctor if you have or have ever had a buildup of fluid in the chest cavity or the stomach area or kidney disease. Also tell your doctor if you are nauseated.
- Tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking leucovorin, call your doctor.
- Unless your doctor tells you otherwise, continue your normal diet.