Infusion therapy involves the administration of medication through a needle or catheter. It is prescribed when a patient's condition is so severe that it cannot be treated effectively by oral medications or the required medication is not available or effective if used orally. Typically, "infusion therapy" means that a drug is administered intravenously, but the term also may refer to situations where drugs are provided through other non-oral routes, such as intramuscular, subcutaneously or via epidural or intrathecal routes (into the membranes surrounding the spinal cord).

Diseases commonly requiring infusion therapy include infections that are unresponsive to oral antibiotics, uncontrollable pain, dehydration, gastrointestinal diseases or disorders which prevent normal functioning of the gastrointestinal system, and more. Other conditions treated with specialty infusion therapies may include cancers, congestive heart failure, Crohn's Disease, hemophilia, immune deficiencies, multiple sclerosis, rheumatoid arthritis, immune deficiencies and more.

Until the 1980s, patients receiving infusion therapy had to remain in the inpatient setting for the duration of their therapy. Heightened emphasis on cost-containment in health care, as well as developments in the clinical administration of the therapy, led to strategies to administer infusion therapy in alternate settings. For individuals requiring long-term therapy, inpatient care is not only tremendously expensive but also prevents the individual from resuming normal lifestyle and work activities. Home infusion has been proven to be a safe and effective alternative to inpatient care for many disease states and therapies. For many patients, receiving treatment at home is preferable to inpatient care.