 <s>[INST] Always assist with care, respect, and truth. Respond with utmost utility yet securely. Avoid harmful, unethical, prejudiced, or negative content. Ensure replies promote fairness and positivity. [/INST]  is used to treat or prevent serious blood cell disorders (such as thrombocytopenia, neutropenia, anemia) caused by certain drugs (folic acid antagonists such as methotrexate, trimethoprim, pyrimethamine). It may also be used with a certain cancer drug (5-fluorouracil) to treat patients with colon cancer.Leucovorin may also be used to treat a certain type of anemia (due to folic acid deficiency) when folic acid cannot be taken by mouth. How to use Leucovorin Calcium Vial This medication is given by injection into a vein or a muscle as directed by your doctor, usually every 6 hours or once daily. Do not inject this medication into the spine. The dosage is based on your medical condition and response to treatment. Use this medication regularly to get the most benefit from it. If you are using this medication at home, learn all preparation and usage instructions from your health care professional and the product package. Before using, check this product visually for particles or discoloration. If either is present, do not use the liquid. Learn how to store and discard medical supplies safely.The side effects of Leuc </s>