Fosaprepit 150mg Injection blocks the action of chemicals in the body that can make you feel or be sick. It is often used to prevent nausea and vomiting that may be caused due to some medicines or cancer treatment. This medicine helps you recover more comfortably from cancer treatments such as radiation therapy or chemotherapy. It is also effective at preventing nausea and vomiting after an operation (in adults only). It is given as an injection by a doctor and should not be self-administered.