Medicines for Hypopituitarism

What it is

Hypopituitarism is a condition in which the pituitary gland — the "master gland" at the base of the brain — does not produce enough of one or more of its hormones. Because the pituitary controls several other hormone-producing glands and functions, a lack of its hormones has knock-on effects: it can lead to underactivity of the thyroid, the adrenal glands (reducing cortisol), the sex glands (affecting periods, fertility and libido), a lack of growth hormone, and problems with the hormone that controls water balance (causing diabetes insipidus) or with prolactin. The symptoms therefore depend on which hormones are affected and can be wide-ranging and often non-specific — such as tiredness, weakness, weight changes, feeling cold, low mood, loss of periods or libido, and, in children, effects on growth. It can develop gradually and be easily overlooked. Causes include pituitary tumours (and their treatment with surgery or radiotherapy), other conditions affecting the pituitary or the area around it, head injury, and, in some cases (such as severe bleeding after childbirth, Sheehan's syndrome), damage to the gland. One particularly important aspect is a lack of cortisol (from reduced ACTH), because cortisol is essential for the body to cope with stress and illness, and a severe lack can be life-threatening — so people with hypopituitarism affecting cortisol need to know how to manage this during illness. Hypopituitarism is diagnosed with hormone blood tests (and often scans), and is managed by replacing the missing hormones.

How it is treated

Hypopituitarism is managed by endocrine specialists, and the mainstay of treatment is replacing the hormones that are lacking, tailored to which ones are affected — this treatment is usually very effective at relieving symptoms and keeping the person well. Assessment involves hormone blood tests to determine which pituitary hormones are deficient, and investigation of the underlying cause (often including a pituitary scan). Replacement may include: cortisol replacement (such as hydrocortisone) if adrenal function is affected; thyroid hormone (levothyroxine) if the thyroid is affected; sex hormone replacement; growth hormone in some cases; and treatment for diabetes insipidus (with desmopressin) if water balance is affected. A crucial part of care where cortisol is affected is education about "sick day rules" — the person is taught to increase their steroid dose during illness, injury or surgery, and to have emergency injectable steroid and a medical-alert identification, because a lack of cortisol during physical stress can cause a life-threatening adrenal crisis. The underlying cause (such as a pituitary tumour) is treated as needed. Regular monitoring adjusts the hormone replacement and tracks the condition. With appropriate hormone replacement and careful management (especially of cortisol during illness), most people with hypopituitarism can live well. The reassuring message is that hypopituitarism is manageable by replacing the missing hormones, that this effectively relieves symptoms, and that understanding how to manage cortisol replacement during illness is a key safety measure.