Endocrinology Lectures Flashcards
What are some common endocrine problems associated with the Thyroid?
Hyper and Hypo
Goitre - swollen.
Carcinoma thyroid.
What are some common endocrine problems associated with the Adrenal glands?
Addison’s disease
Cushing’s disease
Conns Syndrome
Phaeochromocytoma
What does the hypothalamus produce that stimulates the pituitary gland to release TSH?
Hypothalamus -> TRH
TRH + Pituitary = TSH
TSH + Thyroid = T3 and T4
T3 and T4 = negative feeback/inhibition of both Hypothalamus and Pituitary gland.
What role do T3 and T4 play in their own production?
They inhibit it by inhibiting the release of TRH from the Hypothalamus and the release of TSH from the Pituitary gland
What are the main SIGNS of hypothyroidism?
Facial swelling Hair loss Dry skin Reduced heart rate Husky voice Hypothermia Goitre?
What is the most common cause of drug induce thyroid disease?
Amiodarone.
What thyroid test results would you expect in a patient with secondary hypothyroidism? Why might they be different to those from primary?
Low T3/4
Low TSH as well.
TSH is low as well as secondary is mostly due to a pituitary tumour, so there is no problem per se with the thyroid gland itself but the pituitary gland is unable to manufacture sufficient TSH.
What thyroid function test results would you expect from someone with hyperthyroid?
High T3/4 but LOW TSH as the problem is with the thyroid gland itself creating too much T3/4 not with the hypothalamus (TRH) or the pituitary gland (TSH)
What thyroid test results would you expect in a patient with primary hypothyroidism?
Low T3/T4
High TSH - this is because the thyroid is unable to produce T3/4 for whatever reason but the pituitary gland continues to pump out TSH.
What are the main SIGNS of hyperthyroid?
Tremor Warm skin Agitation Goitre Exophthalmous Atrial fibrillation.
What is Exophthalmous?
Graves’ ophthalmopathy may occur before, with, or after the onset of overt thyroid disease and usually has a slow onset over many months. Bulging of eye out of socket.
What are the symptoms of hypothyroid and how does it differ via hyperthyroid?
Fatigue vs palpitations Constipation vs diarrhoea Weight gain vs weight loss/anorexia Depression/ psychosis Menorrhagia hearing loss.
Thyroid disease management consists of: [3]
Restoring the patient wellbeing and to return TSH levels to normal.
To relieve any symptoms.
To manage any underlying condition.
How should hypothyroidism be treated?
Replacement doses of levothyroxine: T4, the cells/organs of the body can break T4 down into T3 via deiodinases.
How should hyperthyroidism be treated?
- Medication that stops the thyroid producing too much of the thyroid hormones.
- Radioiodine treatment - where radiation is used to damage the thyroid, reducing its ability to produce thyroid hormones.
- Surgery to remove some or all of the thyroid, so that it no longer produces thyroid hormones.
Thionamides are a common treatment for what?
Overactive thyroid.
Carbimazole and propylthiouracil are examples.
What are some examples of thionamides and what are they used to treat?
Overactive thyroid,
Carbimazole and propylthiouracil are examples.
What is the common pathology of the pituitary gland?
- Non-functioning tumours - so no hormones are released (hard to detect)
- Functioning tumours - too much hormone?
- Empty - born with very little pituitary gland - lack of hormones.
- Pituitary infarction (rare - blood supply is normally very good - can occur after pregnancy)`
How common are pituitary tumours?
Rare, usually benign. Occasionally metastases from brain cancer.
Presents as hypersecretion of one or more hormones.
Why does very specific vision loss sometimes occur with pituitary tumours?
Pressing on the optic chasm, where the retinal nerves cross over.
What percentage of pituitary tumours are of the non-functioning variety and how are they treated?
90%
Surgery
Treatment goals: protect eyesight, restore pituitary function, prevent rupture of carotid artery.
How are functioning pituitary tumours treated?
Dopamine receptor agonists:
Ergot derived: Cabergoline and Bromocriptine.
Non-ergot derived: quinagolide.
How do dopamine receptor agonists work in the treatment of functioning pituitary tumours?
What are some examples?
Prolactinomas = most common type of functioning tumour.
Prolactin is inhibited by the release of dopamine from the hypothalamus. Enhancing dopamine levels via agonists = tumour shrinkage, 40% in remission after 3 years.
What monitoring is required for treatment with Ergot derived dopamine agonists?
There are concerns over valvular and retroperitoneal fibrosis (requires baseline then annual echo) - Non-ergot derived (Quinagolide) not impacted.
Why is bromocriptine preferred in pregnancy over cabergoline?
Cabergoline has a long half-life.
What is Quinagolide?
Non-ergot derived dopamine agonist: prolactinoma pituitary gland tumour treatment.
How is pituitary gland tumour managed in pregnancy?
Bromocriptine.
May be able to stop the treatment depending on the size of the tumour. However, prolactin levels naturally increase during pregnancy so we wouldn’t want to stop the treatment but most commonly it is stopped during pregnancy.
What is acromegaly?
Excess GH = teeth separation, feet get bigger, gigantism.
First line treatment is surgery. If not effective: somatostatin analogues.
What are the treatment options for acromegaly?
Surgery, then somatostatin analogues if not effective.
What is Cabergoline?
Ergot derived dopamine agonist used in treatment of prolactinoma pituitary tumours.
How do somatostatin analogues benefit those with acromegaly?
Inhibit production of many hormones including GH. Messy and V expensive hormone.
How are somatostatin analogues administered in those receiving treatment for acromegaly?
1/12 Depo-injection. igF1 is measured = 60% achieve normal levels but tumour shrinkage appears in 30% only.
What is bromocriptine?
Ergot derived dopamine agonist used in the treatment of prolactinoma pituitary tumours.
What are some examples of somatostatin analogues and what might they be used to treat?
Octroetide
Lanreotide
Half-life of 2 hours.
Used to treat acromegaly as they inhibit the production of many hormone. (Acromegaly: too much GH)