Subcutaneous Insulin Administration

Abstract

Insulin is administered mostly via the subcutaneous route. Because insulin is a protein, it is degraded by gastric secretions, and at present no oral formulations of insulin are commercially available. Insulin can be administered intravenously or by intramuscular injection, but these routes are reserved for treating metabolic emergencies or for specific management of hospital inpatients (Chaps. 6 and 7). Inhaled insulins were developed as a way of bypassing the gut. However, the only inhaled insulin to gain regulatory approval was withdrawn in 2007, because of fears about serious side effects. Insulin can be added to peritoneal dialysate, and implantable pumps in the abdominal wall can deliver insulin directly into the peritoneal cavity but are seldom used.