Panhypopitutarism

S Atkin

Reader in Medicine, University of Hull

Endocrine Nurses Training Course 10-12 September 2003
St Aidan's College, University of Durham, Windmill Hill, Durham DH1 3LJ

Panhypopituitarism refers to decreased pituitary hormone secretion as a result of pituitary or hypothalamic dysfunction resulting in loss of all of the anterior pituitary hormones of ACTH, TSH, LH, FSH, Prolactin, with or without loss of antidiuretic hormone from the posterior pituitary gland. This is caused by either pituitary or hypothalamic damage.

The most common cause (76%) is through a pituitary tumour or its treatment by surgery and/or radiotherapy, although other conditions, such as a craniopharyngeoma affecting the hypothalamus (13% of cases) may also cause the problem.

The symptoms of panhypopituitarism depend on whether it has been caused acutely, such as pituitary infarction or surgery, or has developed slowly and insidiously, such as due to a large pituitary tumour or craniopharyngeoma. The symptoms that result are due to loss of the target gland. Thus, the effect due to loss of TSH results in those symptoms due to thyroid deficiency. However, loss of the anterior pituitary hormone secretion may be total or partial, such as in ACTH secretion that may only need replacing in times of stress.

Whilst base line investigation with a single blood test may identify hormonal secretory loss, such as for FSH, LH, prolactin and TSH, the secretion of ACTH and GH often needs to be investigated dynamically using the insulin stress test or glucagon stimulation.

Once identified then hormonal replacement to maintain health and wellbeing is necessary: for ACTH deficiency hydrocortisone is given; for TSH deficiency thyroxine is given; for LH/FSH deficiency testosterone is given in men (?women) and estradiol is given to premenopausal women. Growth hormone therapy is available and in my opinion should be given to all patients who have severe deficiency, although this is not agreed by all. Prolactin does not need to be replaced as the only known presentation of prolactin deficiency is the inability to lactate after delivery.

Education is key in ensuring patients are aware of why they are taking their medication and what to do when they are unwell. All patients must carry a steroid card and ideally all patients should wear an SOS bracelet etc. Follow up of these patients when they are established on their medication is for life, but need not be too frequent, perhaps six monthly or so depending on need. However, as general practitioners may distance themselves from these patients as they are seen as complex, a process where they can contact the endocrine service directly should problems arise is optimal.

The opinions expressed in this paper are those of the speaker and do not necessarily reflect the views of the Society