Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Year 2 - endocrinology > Hyperthyroidism > Flashcards

Hyperthyroidism Flashcards

1
Q

What are the causes of hyperthyroidism?

A
  • Grave’s disease
  • Plummer’s disease
  • Viral (de Quervain’s) Thyroiditis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is Grav’es disease?

A

Autoimmune, antibodies bind to and stimulate TSH receptors in thyroid gland. The stimulation of the gland causes growth and forms a smooth goitre.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the symptoms of Grave’s disease?

A
  • Lid lag
  • Other antibodies bind to muscles behind the eyes and causes an exophthalmos
  • Other antibodies cause pretibial myxoedema (hypertrophy) – growth of soft tissue on the shins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is Plummer’s disease?

A

Not autoimmune but a benign adenoma.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the symptoms of Plummer’s disease?

A
  • Toxic nodular goitre
  • No pretibial myxoedema
  • No exophthalmos
  • Also called a “Hot Nodule” on a thyroid uptake scan
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the general signs and symptoms of hyperthyroidism?

A
  • Weight loss despite increased appetite
  • Dyspnoea
  • Palpitations, tachycardia
  • Sweating and heat intolerance
  • Diarrhoea
  • Lid lag and other SNS features
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Why does hyperthyroidism cause SNS effects?

A

Thyroxine sensitises beta-adrenoceptors to ambient levels of adrenaline and noradrenaline (not more adrenaline, just more sensitive receptors).
Leads to SNS activation causing tachycardia, lid lag, etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is Viral Thyroiditis?

A

Hyperthyroidism to hypothyroidism

  • Virus attacks thyroid gland causing pain and tenderness
  • Virus then lyses the cell and so thyroxine spills out into the blood (hyperthyroidism) and then the thyroid is not creating thyroxine so the hyperthyroidism becomes hypothyroidism after around a month
  • Zero iodine uptake on uptake scan
  • After a further month, patient is healthy again
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the signs/symptoms of viral thyroiditis?

A
  • Painful/tender dysphagia
  • Hyperthyroidism
  • Pyrexia – fever
  • Raised ESR – Erythrocyte sedimentation rate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is a thyroid storm?

A

too much thyroid hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the features of a thyroid storm?

A

Medical emergency - 50% of untreated die

  1. Hyperpyrexia – high fever (>41)
  2. Accelerated tachycardia/arrhythmia
  3. Cardiac failure
  4. Delirium/frank psychosis
  5. Hepatocellular dysfunction, jaundice
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the treatment for a thyroid storm?

A
  • Surgery (thyroidectomy)
  • Radioiodine
  • Drugs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the types of treatment for thyroid storm?

A
  1. Thionamides (thiourylenes; anti-thyroid drugs):
    Propylthiouracil (PTU) and Carbimazole (CBZ).
  2. Potassium iodide.
  3. Radioiodine.
  4. Beta-blockers.

All inhibit thyroxine synthesis besides last which combats symptoms.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How do thionamides work?

A

E.G. PTU and CBZ

  • Inhibits TPO and peroxidase transaminase
  • Suppress antibody production in Graves’
  • Reduce T4 to T3 conversion in peripheral tissues (PTU).
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How is PTU used?

A
  • Daily treatment of hyperthyroid conditions – e.g. Graves’, Toxic thyroid nodule
  • Treatment prior to surgery
  • Reduction of symptoms while waiting for radioactive iodine to act
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How long do thionamides take to work?

A

A biochemical effect in hours but no clinical effect until a week or so has passed as there is a large store of normal thyroxine in the thyroid gland that is released for a while.

17
Q

What other drugs may be given alongside thionamides and why?

A

The treatment regimen may include propranolol (beta-blocker) to rapidly reduce tremor and tachycardia

18
Q

What are some unwanted effects of thionamides?

A

Agranulocytosis – reduction or absence of granular leukocytes

Rashes

19
Q

What are some of the pharmokinetic features of thionamides?

A
  • Orally active
  • Carbimazole is a pro-drug (first is converted to methimazole)
  • Plasma half-life of 6-15 hours
  • Crosses placenta (secreted in breast milk) – Carbimazole more so than PTU
  • Metabolised in liver and secreted in urine
20
Q

What is the follow up for thionamides?

A

Stop anti-thyroid treatment after 18 months.

Review patient frequently.

21
Q

What is iodide treatment and how does it work?

A

Potassium iodide

  • Inhibits iodination of TG
  • Inhibits hydrogen peroxide generation
  • WOLF-CHAIKOFF EFFECT (ingesting large amounts inhibits thyroid hormone synthesis)
22
Q

When is iodide treatment used and how long does it take for effects to show?

A
  • Preparation of hyperthyroid patients for surgery
  • In severe thyroid storm crisis patients
  • Symptoms reduce in 1-2 days
  • Size of gland reduce in 10-14 days
23
Q

What are unwanted side effects of iodide treatment?

A

Allergic reactions

24
Q

Describe the pharmakokinetics of iodide treatment

A

Orally active – Lugol’s solution with maximum effect after 10 days’ continuous administration

25
Q

When is radioiodine used and how does it work?

A

Treats hyperthyroidism and thyroid cancers.

Radioiodine accumulates in thyroid and emits beta particles which destroy follicular cells.

26
Q

What are some cautions that should be taken following radioiodine treatment?

A
  • Contact with small children avoided for several weeks after receiving.
  • CONTRA-indicated in pregnancy and breast feeding.
27
Q

Describe the pharmakokinetics of radioiodine

A
  • Discontinued anti-thyroid drugs 7-10 days’ prior so radioiodine is taken up by thyroid as much as possible
  • Administered as a single dose orally
  • Radioactive half-life of 8 days
  • Radioactivity negligible after 2 months
28
Q

What is the dose of radioiodine given for Graves and thyroid cancer?

A

Graves – approx. 500 MBq.

Thyroid cancer – approx. 3000 MBq.

Year 2 - endocrinology (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions