hyperthyroidism Flashcards
1
Q
what is thyrotoxicosis
A
excess circulating thyroid hormones (due to any cause, incl hyperthyroidism)
2
Q
signs and symptoms of hyperthyroidism
A
- goitre
- hyperactivity
- disturbed sleep
- fatigue
- palpitations
- anxiety
- heat intolerance
- increased appetite with unintentional weight loss
- diarrhoea
3
Q
which of the following is NOT a sign/symptom of hyperthyroidism
- hyperactivity
- goitre
- heat intolerance
- cold intolerance
- palpitations
- increased appetite and weight loss
A
cold intolerance is a sign/symptom of HYPOthyroidism
4
Q
complications of hyperthyroidism
A
- graves disease
- thyroid storm (thyrotoxic crisis)
- pregnancy complications
- reduced bone mineral density
- HF
- AF
5
Q
4 risk factors for hyperthyroidism
A
- smoking
- family history
- co-existent autoimmune conditions
- low iodine intake
6
Q
which of the following is a risk factor for hyperthyroidism: female patient, 45 years, smoker, suffers from allergic rhinitis, has a diet that mainly consists of animal protein foods and sea vegetables
A
smoking = risk factor
also more likely in females
7
Q
what is primary hyperthyroidism
A
condition arises from thyroid gland itself rather than due to a pituitary or hypothalamic disorder
8
Q
main cause of primary hyperthyroidism is
A
graves disease (autoimmune disorder mediated by antibodies that stimulate TSH receptor)
9
Q
2 other causes of primary hyperthyroidism (apart from graves disease)
A
- drug induced thyrotoxicosis
- toxic nodular goitre - autonomously functioning thyroid nodules that secrete excess thyroid hormone
10
Q
primary hyperthyroidism is more common in…
A
females
11
Q
primary hyperthyroidism can be classed as
A
- overt
- subclinical
12
Q
overt hyperthyroidism
A
TSH levels below reference and FT4 and/or FT3 levels above reference
13
Q
subclinical hyperthyroidism
A
TSH suppressed but FT4 and FT3 within reference
14
Q
suspect hyperthyroidism if features of graves orbitopathy:
A
- excessive eye watering
- double vision
- change in visual acuity or colour vision
- eyelid retraction or lid lag
- proptosis (eyes protruding)
15
Q
assessment of a person with suspected hyperthyroidism - what blood test
A
- check serum TSH initially
- then measure FT4 and FT3 in the same sample if TSH was suppressed
16
Q
in amiodarone induced thyroiditis, what type of goitre is present
A
small goitre
17
Q
in hyperthyroidism caused by amiodarone, do you need to stop amiodarone
A
generally yes to reduce iodine load
however long half life so its effect can still persist
treat promptly with antithyroid meds e.g. carbimazole
18
Q
describe the goitre present in graves disease
A
thyroid gland is usually diffusely symmetrically enlarged without nodules, and there may be a bruit (a sound)
19
Q
does subclinical hyperthyroidism tend to be asymptomatic? if there are signs, this tends to be in which population?
A
yes - clinical symptoms and signs are absent, mild or non-specific. if they are present, they are more likely in younger people
20
Q
can thyrotoxicosis occur without hyperthyroidism and how can it happen?
A
yes. usually transient. can occur due to excess intake of levothyroxine or OTC supplements containing thyroid hormone, or from thyroiditis
21
Q
what is the thyrotoxic phase of postpartum and when does it typically occur and how long for
A
- thyrotoxic PP typically overs between 1-6 months PP and usually lasts 1-2 months
- happens when the thyroid becomes overactive after birth
22
Q
checking TSH in suspected hyperthyroidism
A
- if TSH below normal reference, then measure FT3 and FT4 in the same sample
- overt: low TSH, high FT4 and/or TF3
- subclinical: low TSH, normal FT4 and FT3
23
Q
a patients lab reports show that they have low TSH, and normal FT4 and FT3. what is the diagnosis
A
subclinical primary hyperthyroidism
24
Q
a patients lab reports show that they have low TSH, and high FT4 and/or FT3. what is the diagnosis
A
overt primary hyperthyroidism
25
subclinical primary hyperthyroidism - repeating TFTs to confirm diagnosis
- subclinical: low TSH, and normal FT4 and FT3
- repeat after 3 months after initial result or exclude other causes of transiently suppressed TH and to confirm diagnosis
- if on repeat detesting there is persistently low TH and normal FT4 and FT3, diagnosis is confirmed
26
amiodarone induced hyperthyroidism typically produces the following TFTs results
low TSH, high FT4, raised or normal FT3
27
which OTC supplement can cause assay interference
OTC biotin can cause falsely low TSH and elevate T4 and T3, indicating hyperthyroidism
28
non drug treatment options in graves disease of toxic nodular goitre
specialists may consider radioactive iodine or surgery. whilst awaiting these treatments, offer antithyroid drugs to control hyperthyroidism
29
symptoms of thyroid storm
rapid heartbeat, high temp, high BP, jaundice, loss of consciousness, severe agitation and confusion
30
what to do if a pt has signs of thyroid storm
medical emergency
emergency admission required
31
what to do if pituitary or hypothalamic disorder is suspected
refer urgently to endocrinologist
32
which class of drugs can you consider prescribing whilst awaiting specialist endocrinologist assessment to provide relief of adrenergic symptoms
beta blockers
titrate dose depending on clinical response
helps with adrenergic symptoms e.g. palpitations, tremor, tachycardia, anxiety
33
when to consider seeking specialist advice about starting antithyroid drugs
- troublesome symptoms despite treatment with BB, or if BB not tolerated or contraindicated
- at risk of complications
- taking drug treatment e.g. amiodarone or lithium - may need liaison between specialistt and endocrinologist
34
what is the recommended choice of antithyroid drug
carbimazole
35
before starting antithyroid drugs, check the following
FBC and LFTs
36
name the 2 antithyroid drugs
carbimazole
propylthiouracil
37
why is propylthiouracil not 1st line
- small risk of severe liver injury
38
when can propylthiouracil be prescribed instead of carbimazole
pre-pregnancy
1st trimester
specialist treatment of thyrotoxic crisis
may be used 2nd line if carbimazole not tolerated
39
antithyroid drugs can only be initiated on
specialist advice
40
antithyroid drugs are typically used ..... term to achieve ......
short term to achieve euthyroiditis
41
what does euthyroid mean
normal thyroid gland function
42
when would antithyroid meds be used long term?
if radioactive iodine treatment or surgery is contraindicated or is declined by the pt
43
in newly diagnosed graves disease that is mild and uncomplicated, how long would treatment be
12-18 months
44
most people with graves disease become euthyroid after how many week of treatment with carbimazole
4-8 weeks
45
which patients may require longer duration of treatment with antithyroid drugs
severe hyperthyroidism, large goitre, recent exposure to iodine
46
after euthyroid is achieved, two different treatment regimens may be used by a specialist:
titration regimen
block and replace regimen
47
remission rate for both regimens (titration block regimen and block and replace regimen)
remission rate is about 50% if treatment is continued for 6-18 months and then stopped
48
what is titration regimen
- dose of antithyroid drug adjusted regularly depending on FT4 measurements to maintain normal thyroid function
- dose reduction may be needed if FT4 falls to low-normal or below reference, or TSH increases, indicating development of hypothyroidism
- aim is to titrate to lowest dose needed to maintain euthyroid state
49
what is block and replace regimen
- antithyroid drug used at high doses to block synthesis of thyroid hormone
- FT4 level monitored and LT4 added in when FT4 in reference range
- adjustments to LT4 dose are made to maintain FT4 in reference range
50
how does radioactive iodine treatment work
induces damage of DNA leading to death of thyroid cells, causing decrease in thyroid function and/or reduced thyroid size
51
what is 1st line definitive treatment for adults with graves disease and those with toxic multi nodular goitre?
radioactive iodine treatment
52
how long after radioactive iodine treatment do most pt with graves become euthyroid and hypothyroid
euthyroid and then hypothyroid within 6weeks to 6 months after completing iodine treatment
53
radio protective measures to follow after radioactive iodine treatment
avoid close prolonged contract with children and pregnant women for after 3 weeks after standard dose radioactive treatment
54
which subset of patients with graves disease is radioactive iodine treatment contraindicated in and why (3)
- contraindicated in pt with graves disease with active to severe orbitopathy as it can cause exacerbation of orbitopathy or de novo development
- pregnant or planning to become pregnant in the next 4-6 months as it crosses placenta and can cause severe hypothyroidism in foetus
- contraindicated in breastfeeding
55
advice about pregnancy after having radioactive iodine treatment
- women to avoid becoming pregnant for at least 6 months after treatment
- men to not father children for at least 4 months after treatment
56
why is pre-op treatment with antithyroid drugs, aiming for euthyroid given?
reduces risk of thyrotoxic crisis which may be precipitated by surgery
57
post op complications
hypothyroidism
hypocalcaemia due to hypoparathyroidism (often transient)
vocal cord paresis due to damage to recurrent laryngeal nerve
58
1st line graves disease
radioactive iodine under specialist care
recommended as definitive treatment unless unsuitable or remission likely to be achieved with antithyroid drugs
59
1st line in pt with graves disease in pt whom an antithyroid drug is likely to achieve remission (e.g. mild and uncomplicated cases)
carbimazole or radioactive iodine
60
carbimazole 2 types of regimens for graves disease (e.g. if pt has mild and uncomplicated case graves disease and antithyroid drug is likely to achieve remission)
- 12-18 month course either using block and replace or titration regimen and review need for further treatment
- block and replace: fixed high dose carbimazole with levothyroxine
- titration regimen: dose based on TFTs
61
what to do if a pt with graces disease has persistent or relapsed hyperthyroidism despite antithyroid treatment
consider radioactive iodine or surgery
62
what to do in pt with graves disease who have side effects to carbimazole, pregnant or trying to conceive within following 6 months, or history of pancreatitis
consider propylthyiouracil
63
what to do if agrunolycytosis develops during antithyroid treatment
stop and do not restart
64
management of suspected graves orbitopathy if diagnosis is suspected
- arrange emergency admission or seek immediate advice from ophthalmologist with special interest in thyroid eye disease if pt has suspected sight threatening complication
- arrange routine referral to ophthalmologist with special interest in thyroid eye disease for all other people
65
whilst waiting for specialist assessment regarding pt with suspected graves orbitopathy, advice pt on
- smoking cessation
- artificial tears to lubricate eyes
- avoid irritation and damage to eyes e.g. use dark glasses, avoid dust, wear eye protectors during sleep
- elevate head of bed to relieve morning eye swelling if needed
66
treatment of transient thyroxoticosis without hyperthyroidism
usually only needs supportive treatment (for example, beta-blockers).
67
1st line definitive treatment for pt with toxic nodular goitre and alternative
- 1st line under specialist care is radioactive iodine
- if unsuitable, offer total thyroidectomy or life long antithyroid drugs
- when offering lifelong antithyroid drugs, consider treatment with titration regimen of carbimazole
68
when to consider seeking specialist advice for pt with subclinical hyperthyroidism
For patients who have 2 TSH readings lower than 0.1 mIU/litre at least 3 months apart and evidence of thyroid disease or symptoms of thyrotoxicosis, consider seeking specialist advice.
69
what to consider for pt with untreated subclinical hyperthyroidism
Consider measuring TSH every 6 months
70
pt taking carbimazole or prophylthiouracil should seek urgent medical advice if
- they develop possible symptoms of agranulocytosis or neutropenia e.g. fever, sore throat, mouth ulcers, febrile or non-specific illness, bruising, malaise and to STOP the medication immediately
- will need urgent blood test for differential white cell count
*much more common with carbimazole*
71
a pt comes into the pharmacy asking to buy some strepsils and paracetamol because she is feeling under the weather. you check her PMR and see that she takes antithyroid drugs upon further questioning, she tells you that she has a fever, sore throat and malaise. what do you
- tell her to stop taking her carbimazole
- refer to gp for urgent tests. could be agranulocytosis or neutropenia, so will need an urgent blood test
72
a patient comes into the pharmacy to buy bonjela. he tells you that he has developed some mouth ulcers and has been unwell lately. you look at his pmr and see that he takes carbimazole/propylthiouracil. what do you do
- stop taking the meds
- refer urgently to gp - mouth ulcers can be a sign of agranulocytosis/neutropenia so will need an urgent blood test
73
a patient who is taking carbimazole should seek urgent medical advice if...
- stop medicine and seek urgent medical advice if sore throat, bruising, mouth ulcers, malaise, etc - may be a sign of neutropenia or agranolocytosis
- signs of acute pancreatitis e.g. sudden severe pain in abdomen which is centre of belly, fever n/v - if this is suspected on assessment, stop immediately and manage appropriately
74
if a pt is taking prophylthioruacil, advice them to seek urgent medical advice if
- signs of neutropenia/agranulocytosis e.g. sore throat, malaise, fever, mouth ulcers etc
- symptoms of liver disease e.g. anorexia, n/v, fatigue, abdominal pain, jaundice, light coloured stool, dark urine, itch - arrange for LFTs and if abnormal seek specialist advice
75
a patient on an antithyroid drug has had abnormal LFTs. which drug are they on?
prophylthiouracil
76
a patient presents with fever, nausea and vomiting, and says they have sudden and severe pain in the centre of their stomach. you look at their pmr and see that they are on an antithyroid drug. which one is it and what do you do?
carbimazole
refer
if suspected on assessment, stop taking
77
a patient comes in and says their stool is clay coloured. upon further questioning, they reveal that they also have abdominal pain and feel itchy. you look at their pmr and notice they are on an antihtyroud drug. which one is it and what do you do
propylthiouriacil
refer to gp for urgent LFTs - if abnormal, stop taking and seek specialist advice
78
before starting treatment with carbimazole or prophylthiouracil, what tests need to be performed
full blood count including white cell count and differential
liver function tests
79
do you need routine monitoring of FBC and LFTs in pt taking antithyroid drugs for hyperthyroidism
no unless clinical suspicion of liver damage or agranulocytosis
80
monitoring of antithyroid drug regimens
TSH, FT4 and FT3 every 6 weeks until TSH within reference, then TSH (with cascading to check ft4 and ft3) every 3 months until drugs stopped
81
monitoring after stopping antithyroid drugs
TSH with cascading within 8 weeks of stopping drug, then TSH with cascading every 3 months for a year, then TSH with cascading once a year
82
a female who is taking antithyroid drugs comes to the pharmacy and tells you she is planning a pregnancy. what do you do
refer to endocrinologist and advise to use effective contraception until specialist advice has been bought
83
a female on antithyroid medication comes in to buy a pregnancy test. what do you do
seek immediate medical advice if pregnancy suspected or confirmed
84
a patient on antithyroid drugs comes in and says she is pregnant. what do you do
refer urgently to specialist
85
how long should females who have recently received radioactive iodine be advised to avoid becoming pregnant
for at least 6 months after treatment
86
dose equivalence when substituting carbimazole and propylthioruacil
When substituting, carbimazole 1 mg is considered equivalent to propylthiouracil 10 mg but the dose may need adjusting according to response.
87
carbimazole MHRA risk of congenital malformations
- when used during pregnancy, esp 1st trimester and at high doses (15mg daily or more)
- women of CB potential to use effective contraception during treatment
- only consider in pregnancy after thorough risk-benefit assessment and use lowest effective dose without additional admin of thyroid hormones
- close maternal, foetal and neonatal monitoring recommended
88
carbimzole MHRA risk of acute pancreatitis
- stop immediately and permanently if it ioccurs
- do not use in pt with history of acute pancreatitis associated with previous treatment as re exposure can result in life threatening acute pancreatitis
89
carbimazole contraindicated in
severe blood disorders
90
which trimester should carbimazole be avoided in for sure
1st trimester
91
carbimazole in pregnancy and bf
- only use in pregnancy after through risk-benefit assessment
- use lowest effective dose in breastfeeding
92
carbimazole safety info - neutropenia and agranolycotiss
- Important: recognise bone marrow suppression induced by carbimazole and the need to stop treatment promptly
- Pt to report any signs and symptoms suggestive of infection - esp sore throat
- WBC count performed if any clinical evidence of infection
- Stop promptly if any clinical or laboratory evidence of neutropenia
93
titration regimen of carbimazole for hyperthyroidism dose
-15-40mg daily, continue until euthyroid (normal thyroid function with normal TSH and T4)
- euthyroid usually after 4-8 weeks of treatment
- high dose under specialist supervision only
- then reduce to 5-15mg daily
- reduce dose gradually
- usually 12-18 months
94
blocking replacement regimen of carbimazole for hyperthyroidism dose
- in combo with levothyroxine
- 40-60mg daily
- usually 18 months
95
pt and carer advice carbimazole
Contact Dr IMMEDIATELY if sore throat, mouth ulcers, bruising, fever, malaise, non specific illness develops
96
dose of propylthiouriacil for hyperthyroidism
initially 200-400mg daily in divided doses until pt euthyroid
then reduce to 15-150mg daily in divided doses
initial dose should be gradually reduced to maintenance dose
97
use of propylthiouracil in pregnancy
- can be given but DO NOT GIVE BLOCKING REPLACEMENT REGIMEN
- given 1st trimester as crbimzole is especially teratogenic during this period
- only use lowest dose that will control hyperthyroid state
- requirements in graves disease tend to fall during pregnancy
98
which regimen of propylthiouracil is not suitable in pregnancy
blocking replacement regimen
99
a patient is in her second trimester of pregnancy. what antithyroid drug is suitable
carbimazole
100
use of proylthiouracil in pregnancy
use lowest effective dose
101
monitoring of proptylthuouracil in breastfeeding
monitor infants thyroid status
102
monitoring requirements of propylthiouracil
monitor for hepatoxicity
103
pt and carer advice - propylthiouracil
Recognise signs of liver disorder and advised to seek prompt medical attention if symptoms such as anorexia, n/v, fatigue, abdominal pain, jaundice, dark urine or pruritis develop
104
dose of levothyroxine in blocking replacement regimen in combination with carbimazole
50–150 micrograms daily therapy usually given for 18 months.
105
is low or high iodine intake associated with hyperthyroidism?
low iodine intake = HYPER
high iodine intake = HYPOthyroidism
