Adrenal pharmacology Flashcards
Explain anatomy of the adrenals
The adrenal gland lies on the top of the kidney and consists of two major layers the cortex and the medulla. The cortex is then further divided into 3 layers, the outer layer the zona glomerulosa which synthesises aldosterone, a mineralocorticoid, and a middle layer the zona fasiculata which synthesises cortisol and androgens. The adrenal medulla is shown in blue which generates adrenaline.
Adrenaline Medulla
The adrenal medulla synthesises adrenaline and to a lesser extent noradrenaline. Adrenaline has major uses in the treatment of cardiac arrest and in the form of the ‘Epipen’ to treat the acute respiratory effects seen in anaphylactic shock. Noradrenaline is probably the better agent to acutely stimulate the heart in shock. In a broader pharmacology context consider the major drug groups which interfere with the effects of the catecholamines,, noradrenaline and adrenaline such as the alpha adrenoceptor and beta adrenoceptor antagonist, the beta adrenoceptor agonists used in asthma and the antidepressant uptake inhibitors used to treat depression.
What are the two major steroids produced by the adrenal cortex ?
The two major steroids are produced by the adrenal cortex are cortisol and aldosterone
Glucocorticoid - cortisol
Mineralocorticoid - Aldosterone
if problem with piturary dont need to replace mineralocorticoud
If problem is with both both need replaces
How to treat addisons
Adrenal Cortex
Cortisol (glucocorticoid
+ weak mineralocorticoid)
Aldosterone (mineralocorticoid)
What can steroid receptors be divided into ?
Steroid receptors can be divided into 5 types glucocorticoid, mineralocorticoid and 3 further types for androgens, progestins and oestrogens.
steroid receptors are located in the cytoplasm
Gluco corticoid anti-inflammatory effect
One anti-inflammatory effect is mediated through the synthesis of a protein called lipocortin which inhibits the enzyme phospholipase A2, an activator of the pro-inflammatory arachidonic acid cascade
Glucocorticoids : Immunosuppression
The major mechanism of immunosuppression includes decreased clonal expansion of T-lymphocytes and fibroblast activity together with reduced activation of neutrophils, macrophages and mast cells. Osteoporosis, a chronic adverse effect of glucocorticoids, is driven by an increase in bone reabsorption (osteoclast) and a decrease in bone synthesis (osteoblast).
What are glucocoticoids
Anti inflammatory
Immuno sepressents
What is hydrocortisone ?
CORTISOL
Explain hydrocortisone
What is prendisolone
What can glucocorticoids be used for ?
Explain adverse effects of long term glucocorticoids and mineralcorticoids
Mineralcorticoid
Hypertension
Fluid retention
K/Ca loss
Glucocorticoid
Diabetes
Osteoporosis
Muscle wasting
Peptic ulcer
Cushing’s syndrome moon face
Striae, acne
Increased Susceptibility to infection
presentation of infection may be atypical
serious infection can reach more advanced stage before recognition eg TB
dormant infection can activated eg amoebiasis
fungal/viral infection can be exacerbated
Avoid contact
with chickenpox, measles and shingles
risk of severe chickenpox (if haven’t had disease) – pneumonia, hepatitis, vascular coagulation
What happens when you stop steroids +++ adrenal supression++++
Depending on the dose regimen, prednisolone can be withdrawn more quickly from higher doses down to a 7.5mg dose equivalent to the daily production of cortisol, after which it must be withdrawn more slowly. In some cases adrenal atrophy can persist for years after stopping therapy.
Eg if they are on 30mg can be taken down to 7.5 quite quickly but be very careful from 7.5 downwards !!
What was the relationship between corticosteroids and covid -19
