Mesna Injection is used to prevent ifosfamide-induced hemorrhagic cystitis (bleeding in the bladder that may be caused as a side effect due to treatment with a cancer chemotherapy drug called ifosfamide). However, it is not used to reduce the risk of bladder bleeding due to other medical conditions. Mesna Injection is given under the supervision of a doctor. The dose and duration of the treatment vary based on your need and response to treatment. You should take it exactly as your doctor has advised. Taking it in the wrong way or taking too much can cause very serious side effects. It may take several weeks or months for you to see or feel the benefits but do not stop taking it unless your doctor tells you to. Some common side effects of this medicine include nausea, headache, lightheadedness, lethargy, and abdominal pain. It is advised to drink at least 1 liter of fluid daily when you are on treatment with this medicine. You should seek immediate medical attention if you experience signs of severe allergic reactions like rash, itching, breathing difficulty, chest tightness, and swelling of the mouth, face, lips, or tongue while taking this medicine. Regular blood tests are required to check your blood cells along with the kidney, liver, and blood uric acid levels. Before taking it, tell your doctor if you have an autoimmune disorder, liver, or kidney problems or are taking any medicines to treat infections. Many other medicines can affect, or be affected by, this medicine so let your doctor know all medications you are using. This medicine is not recommended during pregnancy or while breastfeeding. The use of effective contraception by both males and females during treatment is important to avoid pregnancy.