1
Q
where are thyroid hormones synthesised
A
- thyroid follicles
- colloid
2
Q
what are key building blocks of thyroid hormones
A
tyrosine and iodine
3
Q
what are T3 and T4 bound together by
A
thyroglobulin
4
Q
is T3 active
A
yes
5
Q
what is most circulating T3 derived from
A
T4 (deiodination)
6
Q
are T3 and t4 extensively protein bound in plasma
A
yes
7
Q
what are t3 and t4 bound to in plasma
A
thyroxine-binding globulin (TBG) and transthyretin thyroxine-binding pre albumin (TTR)
8
Q
where is thyrotrophin-releasing hormone (TRH) released from
A
the hypothalamus
9
Q
where is TSH secreted from
A
the anterior pituitary
10
Q
where is thyroid hormone secreted from
A
thyroid gland
11
Q
steps of thyroid hormone secretion
A
- hypothalamus secretes TRH
- this causes anterior pituitary to secrete TSH
- this causes thyroid gland to secrete thyroid hormone
12
Q
can you have neg feedback of thyroid hormone
A
yes – when T3 and T4 gets too much it stops secretion of TRH and TSH
13
Q
what does euthyroid state mean
A
thyroid hormone secretion is normal
14
Q
what does hypothyroid state mean
A
thyroid hormone secretion is low (also referred to as myxoedema)
15
Q
what does hyperthyroid state mean
A
thyroid hormone secretion is excess (referred to as thyrotoxicosis)
16
Q
what does TSH do
A
- stimulate t3 and t4
- increase protein synthesis in follicular epithelial cells
- increase DNA replication
- cell division
- increase rough ER and cell machinery required for protein synthesis
17
Q
what happens to the thyroid if exposed to greater TSH conc
A
will undergo hypertrophy – results in goitre
18
Q
what is goitre
A
big swollen neck
19
Q
can goitre occur in any thyroid state
A
yes, most commonly hypothyroidism
20
Q
what does iodine deficiency disease cause
A
- mental retardation
- reduction in physical growth
- deaf-mutism
21
Q
what is the most extreme manifestation of iodine deficiency known as
A
cretinism
22
Q
what cause iodine deficiency disease
A
- inadequate diet intake
- maternal iodine deficiency during pregnancy
23
Q
what household food has been made to contain iodine
A
salt
24
Q
what are the TSH and T4 levels in hyperthyroidism
A
low TSH and high T4
25
what are the TSH and T4 levels in primary hypothyroidism
high TSH and low T4
26
what are the TSH and T4 levels in secondary hypothyroidism
low TSH and low T4
27
what is primary hypothyroidism
any condition characterised by low plasma T3 or T4 and increased TSH
28
symptoms of hypothyroidism
- cold intolerance
- weight gain
- bradycardia
- tiredness
- constipation
- forgetfulness/personality changes eg depression
- pale, dry skin
- puffiness of face
29
what are most cases of hypothyroidism caused by
damaged or loss of thyroid tissue
can also be due to inadequate iodine consumption
30
what is the most common cause of primary hypothyroidism
hashimotos thyroiditis
31
what is hashimotos thyroiditis
autoimmune disease (antibodies to thyroid peroxidase)
32
what gender is hashimotos more common in
women
33
does T4 and TSH increase or decrease with hashimotos
it increase
34
treatments of primary hypothyroidism
- levothyroxine (synthetic thyroid hormone that's identical to thyroxine (T4) )
- liothyronine (synthetic form of T3)
35
should pt be monitored while on levothyroxine
yes at annual intervals -- more frequently with children and pregnant women require monthly monitoring
36
do pregnant women need an increase in their dose of levothyroxine
yes by 50-100%
37
why is early hypothyroidism treatment essential in neonates
to prevent mental defects
38
side effects of levothyroxine
- hair loss
- headaches
- sleep issues
- nervousness
- fever, hot flashes
- pounding heart
- appetite/weight changes
39
is liothyronine commonly used
no as its not recommended
40
risks of liothyronine
- osteoporosis
- arrhythmia
41
duration of levothyroxine
single dose reaches max effect in 10 days and passes off in 2-3 weeks
42
duration of liothyronine
single dose reaches max effect in 24 hr and passes off in 1 week
43
why is liothyronine not recommended
because its 5 times as biologically potent as T4
44
is secondary hypothyroidism common
no
45
what causes secondary hypothyroidism
when the pituitary doesn't produce TSH or hypothalamus doesn't produce TRH
46
what are T3, T4 and TSH levels like in secondary hypothyroidism
low
47
what are symtoms of secondary hypothyroidism
very similar to primary hypothyroidism and so treated in same manner
48
what is myxoedema coma
the end result of untreated hypothyroidism
progressive weakness leading to a loss of consciousness
49
symptoms of myxoedema coma
- extreme hypothermia
- areflexia
- seizures
- resp depression
50
examples of drugs that affect thyroid function
- corticosteroids
- lithium
- amiodarone
- cholestyramine
51
how do corticosteroids affect thyroid function
decreases basal production of TRH and TSH, consequently decreasing thyroid hormone levels
52
how does lithium affect thyroid function
inhibits the release of thyroid hormones and interferes with their peripheral deiodination
53
how do amiodarone affect thyroid function
contains iodine and can cause both hypothyroidism and hyperthyroidism
54
how do cholestyramine affect thyroid function
reduces the absorption of thyroxine
55
symptoms of hyperthyroidism
- heat intolerance
- palpitations
- weight loss
- restlessness
- fatigue
- increased sweating
- frequent bowel movements
- goitre
56
hormone levels in hyperthyroidism
- thyroid produces excess T4
- reduction in TSH due to neg feedback
- T3 usually elevated as well
57
what is the most common cause of hyperthyroidism
graves disease
58
signs of graves disease
- goiter
- exophthalmos (protruding eyes)
59
what is graves disease
an autoimmune disease
60
what causes graves disease
thyroid stimulating immunoglobulin (TSI)
61
what does TSI do
it activates TSH receptor on thyroid follicular cells which causes increased secretion of thyroid hormones
62
non drug treatment for hyperthyroidism
- surgery
- radioactive iodine
63
how is radioactive iodine given
administers orally
64
when does radioactive iodine have its max effect
around 3 months
65
examples of antithyroid drugs
thioamides:
- carbimazole
- propylthiouracil
66
what does carbimazole and propylthiouracil do
- they're accumulated by the thyroid
- inhibit thyroid peroxides and preven hormone synthesis
67
what does else propylthiouralcil do
- inhibit peripheral diodination
68
onset of antithyroid drugs
slow onset (4-6 weeks)
69
are antithyroid drugs safe
yes but may cause agranulocytosis, therefore can increase risk of infection
MP322
flashcards
Decks in class (24)
# Cards
-
2 Peptic ulcer disease and GORD38
-
3 Inflammatory conditions of the GI42
-
4 Pharmaceutical care of GORD and dyspepsia20
-
5 Chemistry and targets (PPIs and H2 antagonists)14
-
6 Chem of meds to treat GI inflammation13
-
7 Particle science part 141
-
8 Particle science and powered technology 214
-
9 Management of diarrhoea and constipation62
-
10 Steroids as treatment for GIT inflammation14
-
11 Chem of meds used to treat diarrhoea and constipation27
-
13 Malabsorption conditions51
-
14 Absorption and what goes wrong61
-
15 Analytical methods18
-
16 Intro to diabetes57
-
17 Pharmacist role in diabetes5
-
18 Causes of diabetes70
-
19 Insulin Treatment70
-
20 Pharm care of diabetes and thyroid disease51
-
21 Meds for T2D22
-
22 Chemistry of oral diabetics45
-
23 Thyroid disorders69
-
24 Endocrine disorders60
-
25 Chem of thyroid treatments20
-
26 Chem revision lecture35
