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Hyperthyroid (thyrotoxicosis)
Medicine > Endocrinology > Thyroid disorders
Background
information
Patient information
Key messages for this
pathway
Suspected
hyperthyroidism
Signs of thyrotoxicosis
Consider differential
diagnoses
Investigations to
confirm diagnosis of
hyperthyroidism
Subclinical
hyperthyroidism
Distinguish cause of
hyperthyroidism
Follow up
Thyroiditis
Graves' disease
Toxic multinodular
goitre
Thyroid adenoma
Drug-induced
Hyperthyroidism in
pregnancy suspected
Start beta blocker if
symptomatic
Investigations
Investigations
Likely solitary toxic
thyroid nodule
Consider whether safe
to stop drug treatment
Repeat thyroid
function after 4 weeks
and reassess
Initial treatment
Thyrotoxic on repeat
testing
Euthyroid or
hypothyroid
Hyperemesis
gravidarum
Clinical features of
Graves' disease
Thyroid function tests
(TFTs) suggestive of
hyperthyroidism
Refer to
endocrinologist
Monitoring treatment
R
Refer to
endocrinologist
Refer to
endocrinologist
R
R
Information for primary
care about antithyroid
treatment and block
and replace regimen
Initial management
Antenatal
management
Refer to
endocrinologist
Treat with antithyroid
agents
R
Go to hyperthyroidism
treatment
Published: 21-Apr-2011
Valid until: 31-Aug-2012
Printed on: 19-Jan-2012
Postpartum
management
© Map of Medicine Ltd
This care map was published by . A printed version of this document is not controlled so may not be up-to-date with the latest clinical
information.
Page 1 of 14
Hyperthyroid (thyrotoxicosis)
Medicine > Endocrinology > Thyroid disorders
1 Background information
Quick info:
Scope:
• causes and clinical features of hyperthyroidism, including:
• Graves' disease
• toxic multinodular goitre
• thyroid adenoma
• medications
• thyroiditis
• causes and clinical features of hypothyroidism, including:
• autoimmune thyroiditis
• drug-induced thyroiditis
• subacute thyroiditis
• postpartum thyroiditis
• consideration of thyroid storm
• consideration of myxoedema coma
• clinical assessment of hyper- and hypothyroidism
• use of thyroid function tests (TFTs) for diagnosis
• management of hyper- and hypothyroidism
• covers adults age 18 years and older, and pregnant women, in primary and secondary care settings
Out of scope:
• assessment and management of thyroid disorders in children
• management of thyroid nodules
Definition:
• hypothyroidism is caused by underactivity of the thyroid gland:
• primary hypothyroidism describes thyroid hyposecretion due to primary thyroid gland disease
• a fall in thyroid hormone results in increased secretion of thyroid stimulating hormone (TSH) and elevation of serum TSH
concentrations
• secondary hypothyroidism is caused by insufficient TSH stimulation of the thyroid gland due to pituitary dysfunction
• tertiary hypothyroidism is due to diminished hypothalamic thyroid releasing hormone (TRH) release, causing decreased
pituitary stimulation and reduced TSH
• secondary and tertiary hypothyroidism are termed 'central hypothyroidism'
• hyperthyroidism is caused by overactivity of the thyroid gland
• goitre refers to enlargement of the thyroid gland which may or may not cause under or over activity of the gland
Causes of hyperthyroidism:
• Graves' disease
• toxic multinodular goitre
• toxic adenoma
• painful subacute thyroiditis
• silent thyroiditis including lymphocytic and post-partum variations
• iodine-induced hyperthyroidism
• excessive pituitary TSH
• excessive ingestion of thyroid hormone
Causes of hypothyroidism:
• chronic autoimmune thyroiditis (Hashimoto's disease)
• surgical removal of the thyroid gland
• thyroid gland ablation
Published: 21-Apr-2011
Valid until: 31-Aug-2012
Printed on: 19-Jan-2012
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Page 2 of 14
Hyperthyroid (thyrotoxicosis)
Medicine > Endocrinology > Thyroid disorders
• external irradiation
• medications, eg lithium and interferon
Diagnosis:
• thyroid function is tested by taking blood samples to test for serum TSH and free thyroxine (T4)
Incidence and prevalence:
• in the UK, the prevalence of spontaneous hypothyroidism is between 1% and 2%
• in the UK, the reported overall prevalence of hyperthyroidism is between 0.5% and 6.3%
• hypo- and hyperthyroidism is 10 times more common in women than men
References:
British Thyroid Association (BTA). UK guidelines for the use of thyroid function tests. Sheffield: BTA; 2006.
American Association of Clinical Endocrinologists (AACE). AACE medical guidelines for clinical practice for the evaluation and
treatment of hyperthyroidism and hypothyroidism. Jacksonville, FL: AACE; 2006.
Clinical Knowledge Summaries (CKS). Hyperthyroidism. Version 1.1. Newcastle upon Tyne: CKS; 2008.
Clinical Knowledge Summaries (CKS). Hypothyroidism. Version 1.1. Newcastle upon Tyne: CKS; 2009.
Royal College of Physicians (RCP). The diagnosis and management of primary hypothyroidism. London: RCP; 2009.
Wall CR. Myxedema coma: diagnosis and treatment. Am Fam Physician 2000; 62: 2485-90.
Bahn RS, Burch HS, Cooper D et al. The role of propylthiouracil in the management of Graves' disease in adults: report of a meeting
jointly sponsored by the American Thyroid Association and the Food and Drug Administration. Thyroid 2009; 19: 673-4.
National Institute for Health and Clinical Excellence (NICE). Venous thromboembolism: reducing the risk. Reducing the risk of
venous thromboembolism (deep vein thrombosis and pulmonary embolism) in patients admitted to hospital. Clinical guideline 92.
London: NICE; 2010.
The Endocrine Society. Management of thyroid dysfunction during pregnancy and postpartum. J Clin Endocrinol Metab 2007; 92:
S1-47.
Nygaard B. Hypothyroidism (primary). Clin Evid (online) 2010; 01: 605.
Longmore M, Wilkinson I, Rajagopalan S. Oxford Handbook of Clinical Medicine. 6th edn. Oxford: Oxford University Press; 2004.
Seshadri K. Thyroiditis, subacute. eMedicine; 2004.
Nygaard B. Hyperthyroidism (primary). Clin Evid (online) 2008; 03: 611
Royal College of Physicians (RCP). Radio-iodine in the management of benign thyroid disease: clinical guidelines. London: RCP;
2007.
2 Patient information
Quick info:
http://www.patient.co.uk/doctor/Hyperthyroidism-(Thyrotoxicosis).htm
3 Key messages for this pathway
Quick info:
This pathway has been locally developed for South West Hampshire.
Key messages for this pathway:
• in older people, there may be few symptoms. Hyperthyroidism may present with deterioration of pre-existing heart disease,
depression, anorexia or weight loss (apathetic or masked thyrotoxicosis)
• diagnosis of hyperthyroidism is normally made from a suppressed thyroid stimulating hormone (TSH) and raised free thyroxine
(FT4). It is only necessary to measure free triiodothyronine (FT3) when the TSH is suppressed but FT4 is in the normal range
• thyroiditis usually presents with a hyperthyroidism phase followed by hypothyroidism for several months, and then resolution
• in Graves' disease, TSH-receptor antibodies almost always positive and diagnostic, particularly thyroid-stimulating
immunoglobulins (TSIs)
• carbimazole dosage depends on the FT4 level. Warn patients about risk of agranulocytosis. A repeat thyroid function should be
organized after 4-6 weeks of starting carbimazole
Contributors to this pathway:
• Dr Emmanuel Abu, UHS
Published: 21-Apr-2011
Valid until: 31-Aug-2012
Printed on: 19-Jan-2012
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This care map was published by . A printed version of this document is not controlled so may not be up-to-date with the latest clinical
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Page 3 of 14
Hyperthyroid (thyrotoxicosis)
Medicine > Endocrinology > Thyroid disorders
• Dr Alex Freeman, NHSSC
• Dr Azraai Nasruddin, UHS
• Dr Derek Waller, UHS
4 Suspected hyperthyroidism
Quick info:
Clinical features of thyrotoxicosis include:
• dyspnoea, palpitation
• heat intolerance and increased sweating
• restlessness, emotional lability, anxiety, irritability, and insomnia
• weight loss despite increase or similar appetite
• exercise intolerance, fatigue, muscle weakness
• infertility, oligomenorrhoea and amenorrhoea
• reduced libido, impotence and gynaecomastia in men
• polyuria, thirst. generalised itch
• in people with diabetes:
• deterioration in diabetic control
• recurrent hypoglycaemic attacks
In older people, there may be few symptoms. Hyperthyroidism may present with deterioration of pre-existing heart disease,
depression, anorexia or weight loss (apathetic or masked thyrotoxicosis).
5 Signs of thyrotoxicosis
Quick info:
Signs of thyrotoxicosis include:
• agitation
• sinus tachycardia, atrial fibrillation, heart failure, resting tachycardia, dependent oedema
• thyroid enlargement
• tremor
• warm, moist skin; palmar erythema
• onycholysis, pruritus, urticaria, diffuse pigmentation
• diffuse alopecia
• muscle wasting and weakness, proximal myopathy, hyperreflexia
• gynaecomastia in men
• chorea (rare)
• hypokalaemic periodic paralysis in Asian men often precipitated by a large carbohydrate meal or by vigorous exercise.
6 Consider differential diagnoses
Quick info:
Differential diagnoses include:
• anxiety state
• cocaine or amphetamine overdose
7 Investigations to confirm diagnosis of hyperthyroidism
Quick info:
Published: 21-Apr-2011
Valid until: 31-Aug-2012
Printed on: 19-Jan-2012
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This care map was published by . A printed version of this document is not controlled so may not be up-to-date with the latest clinical
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Page 4 of 14
Hyperthyroid (thyrotoxicosis)
Medicine > Endocrinology > Thyroid disorders
Diagnosis of hyperthyroidism is normally made from a suppressed thyroid stimulating hormone (TSH) and raised free thyroxine
(FT4). It is only necessary to measure free triiodothyronine (FT3) when the TSH is suppressed but FT4 is in the normal range.
Overt primary hyperthyroidism diagnosis based on:
• symptoms of hyperthyroidism
• TSH level below the normal reference range (<0.1mU/L)
• elevated level of FT4
• if FT4 is not above the reference range in a person with low serum TSH, FT3 should be measured to confirm a diagnosis of
"T3-toxicosis" . This is typical in :
• mild toxic nodular hyperthyroidism
• early Graves' diseas
Subclinical primary hyperthyroidism diagnosis based on:
• TSH below normal reference range (<0.30mU/L) and FT4 and FT3 within normal range
Secondary hyperthyroidism, caused by TSH-secreting pituitary adenoma, diagnosis based on:
• TSH levels raised
• elevated thyroid hormone levels
• hyperthyroid symptoms
8 Subclinical hyperthyroidism
Quick info:
A diagnosis of subclinical hyperthyroidism is defined as low thyroid stimulating hormone (TSH), but asymptomatic, with normal free
thyroxine (FT4) and free triiodothyronine (FT3).
Subclinical hyperthyroidism should not routinely require treatment, although regular tests for TSH, FT4 and FT3 levels should be
performed to monitor for progression to overt hyperthyroidism. Referral to specialist management will only be required if a goitre
exists or if subclinical hyperthyroidism persists.
In all cases, assess for possible causes, such as non-thyroidal illnesses, relevant drug therapies (e.g. amiodarone, lithium) and
diagnostic agents (radiocontrast dyes).
9 Distinguish cause of hyperthyroidism
Quick info:
Hyperthyroidism may be caused by:
• Graves' disease − presence of thyroid peroxidase antibodies may help to diagnose this condition, if cause of thyrotoxicosis is
unclear
• toxic multinodular goitre:
• associated with low thyroid stimulating hormone (TSH) levels with or without high free thyroxine (FT4) levels
• thyroid scan is useful in diagnosis (refer to Endocrinology)
• distinguished from thyroid adenoma by enlarged thyroid gland and composed of multiple nodules
• thyroid adenoma:
• associated with low TSH levels with or without high FT4 levels
• thyroid scan is useful in diagnosis (refer to Endocrinology)
• medications, eg amiodarone or lithium:
• in amiodarone-induced hyperthyroidism the TSH level is suppressed, FT4 levels are high and FT3 levels are high or normal
• thyroiditis:
• the thyroid may be tender or painful
• erythrocyte sedimentation rate (ESR) is useful in diagnosing subacute thyroiditis
• low radio-iodine uptake along with poor thyroid gland imaging is characteristic (refer to Endocrinology)
10 Follow up
Published: 21-Apr-2011
Valid until: 31-Aug-2012
Printed on: 19-Jan-2012
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Hyperthyroid (thyrotoxicosis)
Medicine > Endocrinology > Thyroid disorders
Quick info:
If the serum TSH level is less than 0.4 mU/L and the person is not on levothyroxine therapy, does not have a non-thyroidal illness,
and is not on drug treatment that could suppress TSH (e.g. glucocorticoids, octreotide, cytokines, dopaminergic agents):
• examine the individual for evidence of hyperthyroidism: measure TSH, FT4, and FT3 within 1–2 months to exclude progression
to overt hyperthyroidism and to determine whether the biochemical abnormality is persistent. Usually, the serum TSH level will
have returned to within the reference range in that time
• if serum TSH remains low with normal FT4 or FT3 levels, repeated testing (serum TSH, FT4, and FT3) is necessary. The
frequency of testing should be based on clinical judgement: every 3–6 months if the person is well and more frequently in
elderly persons or those with underlying vascular disease
• check thyroid peroxidase antibodies for evidence of Graves' disease
• refer for specialist management if a goitre is present or if subclinical hyperthyroidism persists after one or two repeat tests
• untreated subclinical hyperthyroidism should be followed into the long term by testing thyroid function every 6-12 months
11 Thyroiditis
Quick info:
Thyroiditis usually presents with a hyperthyroidism phase followed by hypothyroidism for several months, and then resolution.
Clinical features of thyroiditis may include:
• subacute thyroiditis:
• rapid onset, malaise, fever, and thyroidal pain which may extend to the jaw, ears, or down the anterior chest wall
• extremely tender, enlarged, firm, and irregular thyroid gland that is palpable and diffuse
• silent or postpartum thyroiditis:
• usually within 6 months post-partum
• may be non-specific symptoms, eg tiredness, anxiety
• gland may be mildly enlarged and non-tender
• thyroid peroxidase (TPO) antibody is usually positive
• type 2 amiodarone thyroiditis − small goitre usually present
12 Graves' disease
Quick info:
Clinical features of Graves' disease include:
• diffusely enlarged thyroid gland
• ophthalmology
• inflammatory reaction in the skin, particularly the pretibial region
• acropachy of the fingernails
Rare features of Graves' disease may include:
• vitiligo
• urticaria
Thyroid eye disease occurs in about half of people with Graves' disease − symptoms may include:
• gritty sensation in the eye
• excessive production of tears
• pain on looking up or down or to each side
• feeling of pressure behind the eye
• retrobulbar pain
• double vision
• loss of sight or reduced colour vision
Signs of Graves' disease may include:
Published: 21-Apr-2011
Valid until: 31-Aug-2012
Printed on: 19-Jan-2012
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Hyperthyroid (thyrotoxicosis)
Medicine > Endocrinology > Thyroid disorders
• oedema of the conjunctiva and eyelid
• exposure keratitis
• proptosis
• photophobia
• diplopia
• eyelid retraction or lag
NB: Diagnosis may be difficult when signs and symptoms are uniocular, there is no history of Graves' disease, and there is optic
neuropathy but no proptosis.
13 Toxic multinodular goitre
Quick info:
Toxic multinodular goitre:
• at least two autonomously functioning nodules (requires thyroid isotope scanning)
• usually age over 50 years
• in non-toxic multinodular goitre, pharmacological doses of iodine can cause hyperthyroidism (Jod-Basedow phenomenon)
Clinical features of toxic multinodular goitre include:
• signs and symptoms of thyrotoxicosis
• dysphagia
• dyspnoea
• neck pressure
• non-tender nodules of the thyroid
14 Thyroid adenoma
Quick info:
Clinical features of thyroid adenoma include:
• signs and symptoms of thyrotoxicosis
• unilateral non-tender thyroid mass which is easily palpable
• most common finding is undetectable thyroid stimulating hormone (TSH)
• free triiodothyronine (FT3) levels are often elevated while free thyroxine (FT4) may be normal
• can be asymptomatic but with biochemical hyperthyroidism
15 Drug-induced
Quick info:
Identify whether the patient is currently, or has recently been taking any of the following medications:
• levothyroxine, triiodothyronine or thyroid extract
• amiodarone
• lithium
• interferon
16 Hyperthyroidism in pregnancy - suspected
Quick info:
Thyroid biochemistry in pregnancy:
• normal pregnancy causes a slight rise in thyroid secretion and transient biochemical hyperthyroidism
• serum human chorionic gonadotropin (hCG) concentrations peak at 10-12 weeks and then decline
Published: 21-Apr-2011
Valid until: 31-Aug-2012
Printed on: 19-Jan-2012
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This care map was published by . A printed version of this document is not controlled so may not be up-to-date with the latest clinical
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Hyperthyroid (thyrotoxicosis)
Medicine > Endocrinology > Thyroid disorders
• at peak of serum hCG, free thyroxine (FT4), and triiodothyronine (FT3) concentrations rise, but usually remain within the normal
range
• thyroid stimulating hormone (TSH) concentrations respond by falling appropriately
• 10-20% of pregnant women have subnormal TSH levels at peak hCG concentrations
• as hCG declines, FT4, FT3, and TSH concentrations return to within the normal range
• throughout pregnancy the increase in thyroxine-binding globulin causes an increase in serum total T4 and T3, but this does not
indicate hyperthyroidism as FT4 and FT3 are normal
• biochemical hyperthyroidism is often found in women with hyperemesis gravidarum
17 Start beta blocker if symptomatic
Quick info:
If thyroiditis suspected:
• commence on propranolol 40mg TDS if symptomatic
• do not start carbimazole
18 Investigations
Quick info:
TSH is suppressed to <0.1mU/L in Grave' s disease, with an elevated FT4.
Unless clinical diagnosis is clear (eg the patient has a large symmetrical goitre with ophthalmopathy) antibody assay should be used
to confirm the diagnosis:
• TSH-receptor antibodies almost always positive, particularly thyroid-stimulating immunoglobulins (TSIs) and diagnostic for
Graves' disease
• thyroid auto-antibodies such as anti-thyroglobulin antibodies or anti-thyroid peroxidase antibodies usually present (but not
measured unless subclinical hypothyroidism)
Other investigations:
• haematology – may have normochromic, normocytic or microcytic anaemia
• liver function tests (LFTs) may show mild abnormality and be used as baseline to assess possible drug hepatotoxicity
• blood glucose
• serum calcium may be elevated
19 Investigations
Quick info:
Radionuclide scanning should take place after referral to Endocrinology:
• amount of thyroid uptake is useful in diagnosis of thyrotoxicosis
• helps distinguish thyroiditis from solitary and diffuse toxic nodular goitres
123
• scans can be performed with radioactive I
or
99
Tc
99
123
• Tc isotopes have a shorter half-life and lower radiation exposure compared with I
, and is considerably less expensive
• diagnostic feature is focal uptake with no uptake on contralateral side
20 Likely solitary toxic thyroid nodule
Quick info:
Solitary toxic thyroid nodule:
• requires isotope thyroid scanning after referral to endocrinology
• functioning solitary nodule is almost never malignant
Published: 21-Apr-2011
Valid until: 31-Aug-2012
Printed on: 19-Jan-2012
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This care map was published by . A printed version of this document is not controlled so may not be up-to-date with the latest clinical
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Page 8 of 14
Hyperthyroid (thyrotoxicosis)
Medicine > Endocrinology > Thyroid disorders
• a fine needle aspiration is not indicated
21 Consider whether safe to stop drug treatment
Quick info:
Amiodarone should be stopped immediately and thyroid supplements should also be stopped.
Consider whether stopping lithium or interferon can be safely achieved.
23 Initial treatment
Quick info:
Commence on anti-thyroid medication and refer to Endocrine clinic.
Suggested initial carbimazole dose:
• FT4 < 30pmol/L commence on carbimazole 10mg daily
• FT4 30 – 40pmol/L commence on carbimazole 20mg daily
• FT4 > 40pmol/L commence on carbimazole 40mg daily
Patients with significant adrenergic symptoms (tachycardia, tremor) should also be commenced on propranolol at an initial dose of
40mg TDS for symptom relief. This should be discontinued once patients are biochemically euthyroid.
24 Hyperemesis gravidarum
Quick info:
Graves' disease is the most common cause of hyperthyroidism in pregnancy, after hyperemesis is excluded.
In hyperemesis:
• there is no goitre or ophthalmopathy
• absent symptoms and signs of hyperthyroidism
Biochemical hyperthyroidism is often found in women with hyperemesis gravidarum:
• is associated with:
• severe nausea and vomiting in early pregnancy leading to a greater than 5% weight loss
• higher serum human chorionic gonadotropin (hCG)
• twin and multiple pregnancies
• TSH concentrations are often lower than pregnant control women
25 Clinical features of Graves' disease
Quick info:
Clinical features include:
• clinical hyperthyroidism
• diffuse goitre
• ophthalmopathy
• presence of anti-thyroid stimulating hormone (TSH) receptor antibody
• family history and previous history of Graves' disease
• a bruit over the thyroid gland
26 Monitoring treatment
Quick info:
Endocrinology aim to see patients referred with thyrotoxicosis within 4-6 weeks of referral.
Published: 21-Apr-2011
Valid until: 31-Aug-2012
Printed on: 19-Jan-2012
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Page 9 of 14
Hyperthyroid (thyrotoxicosis)
Medicine > Endocrinology > Thyroid disorders
If there is any delay in patients being seen, a repeat thyroid function should be organized after 4-6 weeks of starting carbimazole.
Patients starting carbimazole should be warned that there is a 1:1000 risk of agranulocytosis. They should be advised to have an
urgent full blood count if they develop significant sore throat or febrile illness while taking carbimazole.
Routine FBC monitoring of patients who do not have any infective symptoms is not recommended.
Thyroid ultrasound scan is not required prior to referral to the endocrine clinic.
27 Thyrotoxic on repeat testing
Quick info:
Post partum thyroiditis usually returns to a euthyroid state within 12 months of delivery.
However, there is a 30% risk of subsequent permanent hypothyroidism. Persistent post partum thyrotoxicosis requires further
investigation to differentiate from Graves' disease, which will include an isotope uptake scan. This will require temporary cessation of
breast feeding. Referral for specialist opinion is recommended.
28 Euthyroid or hypothyroid
Quick info:
Post viral thyrotoxicosis
If euthyroid, further thyroid function check at 1 month and 3 months for possible hypothyroidism.
Subacute thyroiditis is usually short lived and self limiting. Hypothyroidism may follow the thyrotoxic phase in up to 50% of people
and last for 4-12 weeks.
Symptoms are often mild, but may become permanent in 5-10%. If symptoms require prescription of levothyroxine, seek specialist
advice on duration of treatment.
Post partum thyrotoxicosis
Offer long term thyroid function monitoring to women with post partum thyroiditis. Monitoring is recommended annually, and also
before and at 6-8 weeks after future pregnancies.
29 Thyroid function tests (TFTs) suggestive of hyperthyroidism
Quick info:
In hyperemesis:
• serum-free thyroxine concentrations are minimally elevated
• free triiodothyronine (FT3) concentrations are usually not elevated
33 Antenatal management
Quick info:
Thyroid stimulating hormone (TSH) receptor antibody testing in pregnancy helps determine the risk of neo-natal Graves' disease and
is:
• performed in the first trimester for women who have:
• current thyroid overactivity and are receiving antithyroid medications
• been treated successfully with surgery or radio-iodine
• repeated in the third trimester for women who are positive
• the consequences of untreated fetal thyrotoxicosis include:
• low birth weight and head size
• fetal distress in labour
• neonatal heart failure and respiratory distress
Administration of antithyroid medications to the mother during pregnancy can treat the neonate in this situation − close follow-up and
continued treatment is required after delivery.
Fetal thyrotoxicosis:
Published: 21-Apr-2011
Valid until: 31-Aug-2012
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Hyperthyroid (thyrotoxicosis)
Medicine > Endocrinology > Thyroid disorders
• clinical sign of fetal thyrotoxicosis is fetal tachycardia and, if suspected, cordocentesis should be considered
• the risk of neonatal Graves' hyperthyroidism in the babies of mothers with Graves' disease (either those being currently treated
131
on an antithyroid medication and those previously treated by iodine-131 (I ) or surgery and rendered euthyroid or hypothyroid)
should be:
• tested antenatally or during first trimester using the TRAK kit or a bioassay which measures thyroid stimulating
immunoglobulin (TSI)/thyroid stimulating hormone (TSH) binding inhibiting immunoglobulin (TBII)
• communicated to the mother, attending obstetrician, and paediatrician
34 Initial management
Quick info:
Specific treatment of hyperemesis gravidarum with antithyroid agents is not usually warranted as specific supportive management,
eg hydration and corticosteroids may be appropriate.
35 Information for primary care about antithyroid treatment and block and replace regimen
Quick info:
Therapy should be continued for 4-8 weeks until the patient becomes euthyroid, based on free thyroxine (FT4) level. There are 2
options:
• titration regimen − gradually reduce dose to a maintenance dose:
• monitor thyroid function every 4-6 weeks
• optimal duration is 12-18 months
• low dose titration regimen has been shown to have fewer adverse effects than a high dose block-replace regimen
• block and replace regimen − levothyroxine is usually added to a fully suppressive dose of antithyroid drug:
• not recommended during pregnancy
• monitor thyroid function every 3 months
Long-term remission rate of more than 50% unlikely to be achieved even with prolonged (more than 18 months) antithyroid
treatment. People with large goitres and severe hyperthyroidism at diagnosis are less likely to enter into remission.
37 Treat with antithyroid agents
Quick info:
Treatment for Graves' disease:
• optimal treatment is the smallest dose necessary to achieve euthyroidism
• Graves' disease often improves during pregnancy:
• in a minority of patients, treatment can be withdrawn in the third trimester of pregnancy
• propylthiouracil is favoured during the first trimester as carbimazole has been associated (although rarely) with fetal aplasia
cutis
• to avoid fetal hypothyroidism, do not use block and replace regimens in pregnancy
38 Postpartum management
Quick info:
Postpartum management:
• check thyroid function in all mothers who had positive thyroid stimulating hormone receptor antibodies in third trimester of
pregnancy
• breastfeeding:
• mothers can continue treatment with antithyroid medications whilst breastfeeding
• if higher doses of antithyroid medications are used, monitor the baby's thyroid function
Published: 21-Apr-2011
Valid until: 31-Aug-2012
Printed on: 19-Jan-2012
© Map of Medicine Ltd
This care map was published by . A printed version of this document is not controlled so may not be up-to-date with the latest clinical
information.
Page 11 of 14
Hyperthyroid (thyrotoxicosis)
Medicine > Endocrinology > Thyroid disorders
Published: 21-Apr-2011
Valid until: 31-Aug-2012
Printed on: 19-Jan-2012
© Map of Medicine Ltd
This care map was published by . A printed version of this document is not controlled so may not be up-to-date with the latest clinical
information.
Page 12 of 14
Hyperthyroid (thyrotoxicosis)
Medicine > Endocrinology > Thyroid disorders
Key Dates
Published: 21-Apr-2011, by
Valid until: 31-Aug-2012
Evidence summary for Hyperthyroid (thyrotoxicosis)
References
This is a list of all the references that have passed critical appraisal for use in the care map Thyroid disorders
ID Reference
1 British Thyroid Association (BTA). UK guidelines for the use of thyroid function tests. Sheffield: BTA; 2006.
http://www.british-thyroid-association.org/info-for-patients/Docs/TFT_guideline_final_version_July_2006.pdf
2 American Association of Clinical Endocrinologists (AACE). AACE medical guidelines for clinical practice for
the evaluation and treatment of hyperthyroidism and hypothyroidism. Jacksonville, FL: AACE; 2006.
http://www.aace.com/pub/pdf/guidelines/hypo_hyper.pdf
3 Clinical Knowledge Summaries (CKS). Hyperthyroidism. Version 1.1. Newcastle upon Tyne: CKS; 2008.
http://www.cks.nhs.uk/hyperthyroidism#313383001
4 Clinical Knowledge Summaries (CKS). Hypothyroidism. Version 1.1. Newcastle upon Tyne: CKS; 2009.
http://www.cks.nhs.uk/hypothyroidism#252738001
5 Royal College of Physicians (RCP). The diagnosis and management of primary hypothyroidism. London:
RCP; 2009.
http://www.rcplondon.ac.uk/specialties/Endocrinology-Diabetes/Documents/Hypothyroidism.pdf
6 Map of Medicine (MoM) Clinical Editorial team and Fellows. London: MoM; 2011.
7 Contributors representing Royal College of Physicians. 2011.
8 Wall CR. Myxedema coma: diagnosis and treatment. Am Fam Physician 2000; 62: 2485-2490.
http://www.aafp.org/afp/20001201/2485.html
9 Bahn RS, Burch HS, Cooper D et al. The role of propylthiouracil in the management of Graves' disease in
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information.
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Hyperthyroid (thyrotoxicosis)
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Valid until: 31-Aug-2012
Printed on: 19-Jan-2012
© Map of Medicine Ltd
This care map was published by . A printed version of this document is not controlled so may not be up-to-date with the latest clinical
information.
Page 14 of 14