 <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]  cancer (peripheral T-Cell lymphoma-PTCL). Pralatrexate works by slowing or stopping the growth of cancer cells. How to use Folotyn Vial Read the Patient Information Leaflet if available from your pharmacist before you start using pralatrexate and each time you get a refill. If you have any questions, ask your doctor or pharmacist. This medication is given by a health care professional in a clinic or hospital. It is injected into a vein as directed by your doctor, usually once a week for 6 weeks. Tell your doctor or nurse right away if you notice redness, pain, or swelling during your injection. The dosage is based on your body size, medical condition, and response to treatment. Use this medication regularly to get the most benefit from it. To help you remember, mark the days on the calendar when you need to receive the medication. To help prevent mouth sores, your doctor may also direct you to take folic acid and give you vitamin B12 shots. Carefully follow your doctor's directions for all your medications.The side effects of Folotyn Intravenous: Pain or sores in the mouth and throat may occur. Brush your teeth carefully/gently, avoid </s>