Sometimes when people become very ill with a complex disease, they cannot eat, let alone take medications orally. In addition, some medications cannot be given orally because the stomach acids will destroy them, and they will no longer be affective to treat your disease. There are many reasons why medications are introduced into the body other than through the mouth. An alternate to oral treatment is infusion therapy administering medication through the use of a sterile catheter that is inserted into a vein and secured. Infusion therapy refers to any administration of medications in the form of a fluid which is not administered orally.