Hypopituitarism

Hypopituitarism is the consequence of diseases or interventions resulting in deficiency of pituitary hormones. Pituitary hormone replacement is one of the most frequent clinical interventions in pituitary disease, yet is rarely been the subject of rigorous scientific evaluation. With the exception of growth hormone, anterior pituitary hormones are replaced with target hormones (sex steroids, cortisol, and thyroxine), in preference to pituitary trophic hormones, as the former have longer half-lives allowing for oral administration. The precise reason for increased morbidity and mortality associated with hypopituitarism is unclear, but underlines the importance of replacing hormones close to physiological patterns. In an era of ‘evidence-based’ medicine, recommendations are frequently based on clinical experience, consensus guidelines, and retrospective reviews rather than on randomized trials. Within these limitations, this chapter will attempt to give a balanced view on current best practice for replacement therapy in adrenocorticotropic hormone (ACTH), thyroid-stimulating hormone (TSH), and gonadotrophin deficiency.