Injection site reactions (ISRs) are reactions that occur at the site of injection of a drug. They may be mild or severe and may or may not require medical intervention. Some reactions may appear immediately after injection, and some may be delayed.[1] Such reactions can occur with subcutaneous, intramuscular, or intravenous administration.
Drugs commonly administered subcutaneously include local anesthetics, drugs used in palliative care (e.g., fentanyl and morphine), and biopharmaceuticals (e.g., vaccines, heparin, insulin, growth hormone, hematopoietic growth factors, interferons, and monoclonal antibodies).