Chaper 6- Endocrine System Flashcards
What’s another name for anti-dietetic hormone and wheres it produced and stored
Vasopressin
Produced: Hypothalamus
Stored: pituitary gland
What is diabetes insipidus
Increased amount of dilute urine and extreme thirst Due to the body has a lower than normal amount of anti diuretic hormone (controls urine output) caused by complications to the hypothalamus or pituitary
What’s the difference between cranial and nephrogenic DI and what’s the treatments
Cranial is when the hypothalamus doesn’t make enough insulin
Treatment is vasopressin or desmopressin
Nephrogenic is when the kidney doesn’t respond to ADH
Treatment include thiazide diuretics
How is vasopressin and desmopressin different
Desmopressin is more potent and has a longer duration of action
Desmopressin has no vasoconstriction effect, unlike vasopressin
How else is desmopressin used in other than diabetes insipidus treatment
Used in the differential diagnosis of diabetes insipidus
Used to boost factor 8 concentration in haemophilia
Test fibrinolytic response
Has a role in nocturnal enuresis
What other uses beside diabetes insipidus does vasopressin have
Initial Control of oesophageal variceal bleeding in portal hypertension
What can be used in the treatment of hyponatraemia resulting from inappropriate secretion of anti diuretic hormone
Blocking the effect of anti diuretic hormone (demeclocycline)
Vasopressin receptor antagonist (tolvaptan)
What does syndrome of inappropriate anti diuretic hormone cause?
Hyponatraemia
Name a few mineralcorticoid side effects
S/E: Hypertension Sodium retention Water retention Potassium loss Calcium loss
Common side effects of glucocorticoids
Diabetes (increase blood sugars) Osteoporosis (mobilise calcium) Avascular necrosis of the femoral head (death of bone tissue) Muscle wasting Peptic ulcers (anti inflammatory effect) Psychiatric reactions
How are side effects of steroids managed
Using the lowest effective dose for the shortest period possible
Take doses in the morning so they don’t suppress the natural adrenal activity which is most active at night
Alternate days prescribing (not in asthma)
Local treatment wherever possible
What’s the MHRA alert regarding corticosteroids
Report any blurred vision as chorioretinopathy risk have presented
And
Injections contain lactose
What steroid hormones does the adrenal cortex secrete?
(cortisol) -glucocorticoid
Aldosterone - mineralocorticoid
In replacement therapy what replaces cortisol and aldosterone
Cortisol is replaced by hydrocortisone
Aldosterone is replaced by fludrocortisone
In glucocorticoid therapy of other disease, why is hydrocortisone rarely used
As it also has mineralcorticoid activity which can lead to fluid retention
Why does prednisolone remain the drug of choice for most oral corticosteroid treatment
It has the largest margin of safety
What can abrupt withdrawal of a steroid cause
Adrenal deficiency Hypotension Death Withdrawal symptoms Cold and flu like symptoms Itching Weight loss
When is gradual withdrawal or titration needed for steroids
If they’ve been taking >40mg of prednisolone (or equivalent) for more than a week
Been taking evening doses
Received more than 3 week treatment at any dose
Recently repeated courses
Taking short course within a year of stopping long term
Other causes of adrenal suppression
Why should high dose steroids be used with caution in patients with a history of psychiatric problems
It can cause psychiatric reactions like Euphoria Nightmares Insomnia Behavioural changes
Who should people on steroids (immunosuppressive) stay away from
People with chicken pox, shingles, measles
Avoid live vaccines when receiving immunosuppressant
Why should steroids be used with caution in children
Possible growth restrictions
How does corticosteroids interact with warfarin
It enhances the anticoagulation effect at high doses
Reduced anticoagulation effect at low doses
How are potencies of corticosteroids in terms of their anti inflammatory effects compared
High glucocorticoid activity whilst also accompanied by relatively low mineralcorticoid activity (that’s when they’re most useful)
Whys dexamethasone and betamethasone the most suitable for high dose therapy conditions that require suppression
They have very high glucocorticoid activity and insignificant mineralcorticoid activity avoiding fluid retention