Brainscape's Knowledge GenomeTM

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


See full index

Integrated Pharmacology and Therapeutic 3 > THYROID AND PARATHYROID > Flashcards

THYROID AND PARATHYROID Flashcards

1
Q

What are the signs of Hyperthyroidism

A

weight loss, sweating, palpitations, heat intolerance, diarrhoea, rapid heart rate. Long term; thyroid toxicosis

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

What are the signs of Hypothyroidism

A

weight gain, bradycardia, constipation, lethargy, cold intolerance. Long term; myxoedema coma

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

What is the primary TSH- thyroid stimulating hormone

A

problem w thyroid gland; opposite directions

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

What is the secondary TSH- thyroid stimulating hormone

A

problem w the hypothalamus; same directions

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

What is the Causes of Hyperthyroidism

A
  • Graves’ disease (autoimmune disorder; ↑ T3 and T4), toxic multinodular goitre (enlarged or swollen thyroid gland producing lots of T3 and T4) and toxic adenoma (Tumour).
  • Biomarker: Presence of thyroid stimulating immunoglobulin are antibody specific to Graves’ Disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Hyperthyroidism: Agreed Principle

A

No surgery and radioactive iodine while a patient is grossly thyrotoxic (having high levels of T3 and T4) due to risk of precipitating a thyroid ‘storm; extremely high levels of T3 & T4.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Treatment guideline of Hyperthyroidism: Grave’s disease

A

Use antithyroid drug long term

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

Treatment guideline of Hyperthyroidism: If there is relapse after anti thyroid drug or surgery not possible

A

Use radioactive iodine (use when above C/I)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Treatment guideline of Hyperthyroidism: If patient has Grave disease and is unwilling or unable to have radioactive tx

A

Use thyroidectomy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What to do before surgery and radioactive iodine tx:

A

Use antithyroid drug for short term to prevent thyrotoxicosis. *Anti-thyroid drugs should be ceased 1 week before tx and recommenced 1 week after tx

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

Hyperthyroidism: If they have symptoms of hyperthyroidism such as palpitation, anxiety, tremor and sweating

A

use beta blocker

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Hyperthyroidism: If they have severe exophthalmos (protrusion of the eyes) in Graves’ disease

A

use Corticosteroids (prednisolone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Anti-Thyroid Drug: What is the initial dose and maintenance dose for Propylthiouracil (PTU)

A

Initially: 200-400mg ddd for 3-4 wks

Maintenance: 25-300mg ddd

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

Anti-Thyroid Drug: What is the initial dose and maintenance dose for Carbimazole

A

Initially: 10-45mg ddd for 3-4 wks
Maintenance: 2.5-40mg daily in single or dd

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Anti-Thyroid Drug: Monitoring

A
  • Agranulocytosis -
    o S & S: sore throat, fever, mouth ulcers
    o FBC
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Block Replace Regimen in Hyperthyroidism:
Combine……. and …… therapy

A

Antithyroid and levothyroxine Therapy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Block Replace Regimen in Hyperthyroidism: What treatment of high dose antithyroid drug

A

(carbimazole 20-40 mg d; PTU 200-400 mg ddd)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Block Replace Regimen in Hyperthyroidism: What treatment of levothyroxine

A

Begin levothyroxine 100-150 mcg when T4 is in normal range (at about 6 wks) while continuing high dose antithyroid drugs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Block Replace Regimen in Hyperthyroidism: Monitor

A

o Follow-up every 3 months to confirm biochemical euthyroidism
o T4 4 times a year
o Check thyroid levels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Hyperthyroidism: what are examples of beta blockers used?

A

Not for long term use
Eg. Propranolol 10-40mg 3-4 times daily; Atenolol 50-100 mg d.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Hyperthyroidism: Radioactive Iodine: C/I

A

C/I in individual < 15 yo, pregnancy and breastfeeding women

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Hyperthyroidism: Radioactive Iodine: How long to taper off antithyroid drugs after radioactive iodine tx

A

2–4 months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Thyroidectomy: What rendered with anti-thyroid drugs prior to surgery to avoid Thyroid storm

A

euthyroid

24
Q

What is the tx for Thyroid Storm

A

Propylthiouracil, IV hydrocortisone, IV fluid, propranolol

25
Q

What are the symptoms relating to Thyroid Eye Disease

A

Artificial tears, Dust protection, Corticosteroid, Surgery, Smoking cessation if applicable

26
Q

Hypothyroidism: Cause

A

Hashimoto’s disease (immune cell attack thyroid cell resulting in hypothyroidism) and thyroid ablation (radioactive iodine, surgery, and drugs)

27
Q

Hypothyroidism Tx: What is used to restore well-being and return TSH to normal range

A

an adequate dose of levothyroxine

28
Q

Hypothyroidism Tx: Before commencing levothyroxine in secondary hypothyroidism, what must be excluded

A

Hypothalamus and pituitary disorder must be excluded to avoid precipitating an Addisonian crisis (if in doubt give glucocorticoid replacement)

29
Q

Thyroxine replacement in hypothyroidism: 1st line

A

Levothyroxine (thyroxine)

30
Q

Thyroxine replacement in hypothyroidism: Levothyroxine Adult dose

A

50-200mcg daily dependent on TSH

~1.6 mcg/kg ideal body weight

31
Q

Thyroxine replacement in hypothyroidism: Levothyroxine dose - Elderly, especially those with IHD

A

25-50mcg daily, increasing by 25mcg daily every 6-8 weeks

If symptoms of cardiac ischemia occur/worsen, dose increases should be avoided

32
Q

Thyroxine replacement in hypothyroidism: Monitoring

A

Thyroid function tests are done every four to six weeks until euthyroidism is achieved

33
Q

What is Myxoedema coma

A

Severe hypothyroidism with physiological decompensation

34
Q

Myxoedema coma Treatment

A

Must be treated aggressively with Liothyronine (T3) + hydrocortisone

35
Q

Myxoedema coma Monitoring

A

Monitor urea, electrolytes and haemotoglical indices, arrhythmia, body temperature

36
Q

Thioureylenes/Thionamides: MOA

A

Inhibition of thyroid peroxidase (enzyme found in thyroid gland to produce thyroid hormone) with reduction in thyroid hormone production and storage

Inhibit iodination of tyrosine. Tyrosine is precursor to thyroid hormones.

PTU also inhibits conversion of T4 to T3 (more active form)

37
Q

Thioureylenes/Thionamides: Side Effects

A

GI upset in first 8 weeks

Hypothyroidism

Agranulocytosis (rare)

Rashes

38
Q

Thioureylenes/Thionamides: Drug Interactions

A

Anticoagulants (warfarin & phenindione) can ix with PTU and can cause ↑ risk of bleeding

Amiodarone, iodinated glycerol, lithium ↓ effects of anti-thyroid drugs

39
Q

Anion Inhibitors (Iodine, Iodide) MOA: Ix short term short-term to render patient euthyroid before surgery in graves disease

A

High doses of iodine - suppress the action of TSH and TRH (negative feedback) symptoms subside within 1-2 days

Inhibit iodination of tyrosine. Tyrosine is precursor to thyroid hormones.

Inhibition of conversion of T4 to T3

Inhibition of thyroid hormone secretion/release

Reduce size and vascularity of gland

40
Q

Anion Inhibitors (Iodine, Iodide) Side Effects

A

Allergic reactions: laryngitis, bronchitis, rashes

Chronic use: depression & impotence

41
Q

Anion Inhibitors: C/I

A

Pregnancy - risk of neonatal hypothyroidism

Breastfeeding - risk of infant hypothyroidism.

42
Q

Radioactive iodine MOA

A

Accumulates in thyroid tissue

Beta radiation emitted selectively destroys thyroid follicle cells

43
Q

Radioactive iodine C/I

A

Pregnancy - risk of neonatal hypothyroidism

Breastfeeding - risk of infant hypothyroidism

44
Q

L-Thyroxine (levo-thyroxine T4) Indication

A

hypothyrodisim

45
Q

L-Thyroxine (levo-thyroxine T4) MOA

A

Thyroxine is converted to T3 in vivo

Has pharmacological properties of endogenous T4

46
Q

L-Thyroxine (levo-thyroxine T4) Drug Interaction

A

Digoxin: Thyroxine reduces digoxin concentration

Cholestyramine, sucralfate, ferrous sulphate, aluminium hydroxide, calcium carbonate: Reduced gut absorption of T4

Oral anticoagulants (warfarin etc.): Thyroxine causes Increased clotting factor elimination Increased anticoagulant effect – increased risk of bleeding

Oral contraceptives containing oestrogens: Increased metabolism and elimination of thyroxine, hence increased dose of L-Thyroxine may be needed

47
Q

Liothyronine (tri-iodothyronine T3) MOA

A

Has chemical and pharmacological properties of endogenous T3

48
Q

Liothyronine (tri-iodothyronine T3) C/I

A

Not recommended in pregnancy and in children because of preferential use of T4 by the brain

49
Q

Hyperparathyroidism Pathophysiology

A

Regulation of PTH is determined by serum calcium level

Dec calcium level will activate parathyroid gland to release PTH which will send signal to kidney, bone and intestine. In kidney, there will be inc calcium reabsorption by dec excretion of calcium thru urine. Mobilise calcium from the bone.

Once there is enough serum calcium, it will send negative feedback to parathyroid gland to dec synthesis of PTH

For hyperparathyroidism, there is: high PTH level, high serum calcium and high calcium/creatinine ratio

50
Q

Primary Hyperparathyroidism cause

A

disorder of parathyroid gland

51
Q

Secondary Hyperparathyroidism cause

A

renal failure; dec calcium reabsorption; unable to activate vitamin D; vitamin D enhances calcium absorption. The increase in PTH hormone in renal Fx is due to chronic hypocalcaemia as a result of the inability of the kidney to activate vitamin D to absorb calcium (negative feedback causing high PTH).

52
Q

Tx of primary hyperparathyroidism: Parathyroidectomy

A

­Indicated for patients with primary & asymptomatic hyperparathyroidism patient with the following:

persistent serum calcium > 2.85mmol/L

eGFR < 60 mL per minute per 1.73 m2

Bone mineral density T-score of less than −2.5 at any one of three sites (i.e., hip, spine, or wrist) and/or any previous fragility fracture

Age < 50 years

53
Q

Tx of primary hyperparathyroidism: Cinacalcet

A

­Initially 30mg bd; up to 90mg tds to qid
­
Monitoring:
monitor calcium and parathyroid hormone concentrations closely and reduce dose if necessary.

54
Q

Tx of secondary hyperparathyroidism:

A

Cinacalcet + calcitriol

Protein restriction

Calcium supplement

Vitamin D supplement; calcitriol

55
Q

Cinacalcet + calcitriol

A

­Cinacalcet: Initially 30mg od; up to 180mg od + Calcitriol: 0.5-1 microg d
­
only used in pts w end-stage renal disease receiving dialysis; Elevated PTH (due to low calcium) will lead to hypercalcaemia and inc risk of osteoporosis. Hence use of cinacalcet with calcitriol is used to achieve calcium homeostasis. Cinacalcet is to Tx the initial high calcium (sensitises receptors on pt gland); cause negative feedback of PTH (lowers PTH). Calcitriol is to Tx the initial low calcium from the renal disease.

56
Q

HYPOPARATHYROIDISM

A

Integrated Pharmacology and Therapeutic 3 (2 decks)

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