Addison's disease

Question 1

What hormone is involved in Addison’s disease?

Answer 1

Low aldosterone and low cortisol

Question 2

Symptoms and signs

Answer 2

Weightloss, weakness
Hypotension (postural symptoms)
Dry skin
Vitiligo
Low BG

Question 3

Causes of Addison’s are?

Answer 3

Can be primary or secondary disease
Causes of primary:
Primary adrenal insufficency
Infiltration, Iatrogenic, Infection, Invasion, Infarction, Immune destruction (most common)

Congenital adrenal hyperplasia- 21-hydroxylase deficiency

Question 4

If immune destruction is the cause of the primary adrenal insufficency what antibodies are involved?

Answer 4

Adrenal antibodies usually 21-O-hase antibodies

Question 5

What test’s can be done for Addison’s?

Answer 5

Random cortisol is done (best in the morning)
U+E’s
FBC
Glucose

Synacthen test

Question 6

Explain what results you expect from a Synacthen test?

Answer 6

If normal, when synacthen is given cortisol levels will increase above 450 within 30 minutes.

If you have primary adrenal insufficiency there will be no response as the adrenal gland is not able/isn’t making cortisol

If you have a secondary insufficiency you will get a small increase in cortisol levels, this is because, low levels of ACTH are being release by the body and over time the adrenal gland is being understimulated and therefore the effect of ACTH on the AG/ the sensitivity to ACTH decreases, so less cortisol is produced when it is stimulated.

Question 7

What is the treatment for Addison’s disease?

Answer 7

Hydrocortisione daily (replaces cortisol, is a glucocorticoid) 20-30mg given to mimic diurnal variation

Fludrocortisone daily (replaces aldosterone, binds to mineralcorticoid receptors). 50-300mg given, dose changed according to postural BP, odema, plasma renin levels)

Question 8

What patients do you need to be more careful treating for Addison’s?

Answer 8

Patients on steroids as these can reduce their endogenous steroids so their body will be less able to cope with stress/illness.

In minor short-lived illness or stress e.g. cold, double glucocorticoid dose (hydrocortisone)

If major illness or surgery (vomiting or diarrhoea) -give 100mg hydrocortisone iv stat
50-100mg hydrocortisone 8-hourly

Then reduce by 50% per day
back to normal dose, when stress has reduced.