Xprab 150 IU injection contains pegfilgrastim, a medication used to stimulate the production of white blood cells. It is commonly prescribed to patients undergoing chemotherapy to reduce the risk of infection due to low white blood cell counts. Pegfilgrastim works by promoting the growth of neutrophils, a type of white blood cell crucial for fighting infections. The injection is usually given subcutaneously (under the skin) once per chemotherapy cycle, typically at least 24 hours after chemotherapy. Common side effects may include bone pain, fever, and site reactions like redness or swelling. Regular monitoring by a healthcare provider is necessary to manage side effects and assess effectiveness.