Synopsis
Identify loss of individual or multiple pituitary axes, protect cortisol before other replacement, and provide lifelong cause-specific hormone, fertility, water-balance and emergency follow-up.
- Hypopituitarism may follow pituitary or hypothalamic tumour, surgery, radiotherapy, apoplexy, head injury, subarachnoid haemorrhage, infiltrative disease, infection, genetic disease or immune checkpoint therapy.
- Hormone loss can be isolated, sequential or complete; ACTH deficiency is the immediately dangerous component and may present with normal potassium because aldosterone remains renin-angiotensin regulated.
- In central hypothyroidism, free T4 is low with TSH that is low, normal or only mildly raised; TSH cannot be used as the levothyroxine dose target.
Key red flags
Shock, recurrent vomiting, severe weakness, altered consciousness or hypoglycaemia in a patient with pituitary disease demands immediate hydrocortisone and resuscitation for possible adrenal crisis.
Investigation priorities
Screen the ACTH-cortisol axis before elective replacement or dynamic testing.
Management branches
Pituitary disease or treatment creates symptoms compatible with partial or complete hormone loss.
- Identify urgent cortisol, visual, neurological and sodium threats before arranging non-urgent dynamic investigations.
- Measure paired target and trophic hormones, document exogenous steroids and hormone therapies, and obtain dedicated pituitary imaging where cause is unknown.
Key medicines
HydrocortisoneNICE first-choice replacement is 15 to 25 mg orally each day in two to three divided doses, with the larger dose earlier.
LevothyroxineBegin after cortisol safety is established and titrate an individual once-daily dose to free T4, symptoms, age and cardiovascular status.