The five most common ways to give drugs during treatment for childhood leukemia are:

• Intravenous (IV): Drugs are delivered directly into the bloodstream through a venous catheter in the chest or an IV in the arm or hand. IV medicines can be administered in a few minutes or as an infusion over a number of hours.
• Oral (PO): Drugs—taken by mouth in liquid, capsule, or tablet form—are absorbed into the blood through the lining of the stomach and intestines.
• Intramuscular (IM): Drugs that need to seep slowly into the bloodstream are injected into a large muscle such as the thigh or buttocks.
• Intrathecal (IT): Doctors perform a spinal tap and inject the drug directly into the cerebrospinal fluid (the fluid surrounding the brain and spinal cord).
• Subcutaneous (Sub-Q): Drugs are injected into the soft tissues under the skin of the upper arm, thigh, or abdomen.
• Sublingual (SL): Several drugs are available as lozenges that dissolve quickly when placed under the tongue.