Hyperthyroidism Flashcards
What are the signs and symptoms of hyperthyroidism? (10)
- Goiter
- Hyperactivity
- Disturbed sleep
- Fatigue
- Palpitations
- Anxiety
- Heat intolerance
- Increased appetite
- Unintentional weight loss
- Diarrhea
(Others)
What are the main complications of hyperthyroidism? (6)
- Graves’ orbitopathy
- Thyroid storm (thyrotoxic crisis)
- Pregnancy complications
- Reduced bone mineral density
- Heart failure
- Atrial fibrillation
What are the main risk factors for hyperthyroidism? (4)
- Smoking
- Family history of thyroid disease
- Co-existant autoimmune conditions
- Low iodine intake
Primary hyperthyroidism refers to when the condition arises from the __________ rather than due to a ______________ disorder
thyroid gland
pituitary or hypothalamic
What is the most common cause of primary hyperthyroidism?
Graves’ disease (autoimmune disorder mediated by antibodies that stimulate the thyroid-simulating hormone (TSH) receptors)
What are the less common causes of primary hyperthyroidism? (2)
- Toxic multinodular goiter (autonomously functions thyroid nodules that secrete excess thyroid hormone
- Drug-induced thyrotoxicosis
In overt hyperthyroidism, TSH levels are _______ and FT3 and/or FT4 levels are _______.
Below the reference range
Above the reference range
In subclinical hyperthyroidism, TSH levels are _______ and FT3 and/or FT4 levels are _______.
Low
Within the reference range
What are the aims of treatment for hyperthyroidism? (3)
- Alleviate symptoms
- Align thyroid function tests within or close to the reference range
- Reduce the risk of long-term complications
What are the non-drug treatment options for primary hyperthyroidism? (2)
- Radioactive iodine
- Surgery (total or partial thyroidectomy)
**whilst awaiting these treatments, antithyroid drugs should be offered to control hyperthyroidism
True or false: thyroid storm is a medical emergency
True
Refer patients urgently to an endocrinologist if a pituitary or hypothalamic disorder is suspected, and refer or discuss with an endocrinologist all patients with new-onset hyperthyroidism (base urgency on clinical judgement); if malignancy is suspected, refer patients using a suspected cancer pathway
What three aspects of hyperthyroidism management should be explained to patients?
- Some patients feel well even when their thyroid function tests are outside the reference range
- Even when they have no symptoms, treatment may be advised to reduce the risk of long-term complications
- Symptoms may lag behind treatment changes for several weeks to months
_________ should be considered alongside supportive treatment (eg beta-blockers) for patients with hyperthyroidism, awaiting specialist assessment and further treatment
Antithyroid drugs
Carbimazole is first line
PTU may be offered to patients in whom carbimazole is unsuitable
Before starting antithyroid drugs, check ________ and ________
FBC
LFTs
Under specialist care, ____________ is recommended as first-line definitive treatment for Graves’ disease unless it is unsuitable or remission is likely to be achieved with antithyroid drugs.
radioactive iodine
For patients with Graves’ disease in whom an antithyroid drug is likely to achieve remission (such as in mild and uncomplicated cases), a choice of either ___________ or _____________ should be offered.
carbimazole
radioactive iodine
- Carbimazole should be offered as first-line definitive treatment if radioactive iodine and surgery are unsuitable treatment options
What is the “block and replace” regimen used to treat hyperthyroidism?
Combination of fixed high-dose carbimazole in combination with levothyroxine
What can be offered as an alternative to the “block-and-replace” regimen used to treat hyperthyroidism?
A titration regimen; dose of carbimazole or other antithyroid drug is modified based on thyroid function tests
If patients with Graves’ disease have persistent or relapsed hyperthyroidism despite antithyroid drug treatment, consider ____________ or ___________
radioactive iodine
surgery
PTU should be considered over carbimazole in which patients? (3)
- Patients who experience side-effects from carbimazole
- Patients who are pregnant or trying to conceive
- Patients with a history of pancreatitis
If ___________ develops during antithyroid treatment, stop and do not restart treatment
agranulocytosis
What is the first-line definitive treatment for patients with hyperthyroidism secondary to multiple nodules?
Radioactive iodine under specialist care
What treatment should be offered to patients with toxic multinodular goiter in whom radioactive iodine is not suitable? (2)
- Total thyroidectomy OR
2. Life-long antithyroid drugs
For patients with hyperthyroidism secondary to a single nodule, offer _________ or __________ as first-line definitive treatment
radioactive iodine
surgery (hemithyroidectomy)
If these options are unsuitable, offer life-long antithyroid drugs
Consider treatment with a ________ regimen of carbimazole when offering life-long antithyroid drugs.
titration
Consider measuring TSH every ____ months for patients with untreated subclinical hyperthyroidism.
6
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.
Transient thyrotoxicosis without hyperthyroidism usually only needs __________
supportive treatment (for example, beta-blockers)
What are the causes of thyrotoxicosis without hyperthyroidism? (3)
- Excess intake of levothyroxine
- Excess of over-the-counter supplements containing thyroid hormone
- Thyroiditis
*usually transient
What is the management of hyperthyroidism in pregnancy?
All pregnant females should be referred urgently to a specialist
Females with hyperthyroidism who are planning a pregnancy should be referred to an endocrinologist and advised to use effective contraception until specialist advice has been sought; advise patients to seek immediate medical advice if pregnancy is suspected or confirmed
Pregnant females with severe signs and symptoms of hyperthyroidism (such as thyroid storm) should be __________________.
admitted to hospital
Females who have recently received radioactive iodine should be advised to avoid becoming pregnant for at least __________ after treatment.
6 months
What are the major safety concerns regarding the use of carbimazole? (3)
- Neutropenia and agranulocytosis
- Increased risk of congenital malformations
- Risk of acute pancreatitis
What is the main contraindication to the use of carbimazole?
Severe blood disorders
When substituting, carbimazole 1 mg is considered equivalent to PTU ______ mg but the dose may need to be adjusted according to response
10
What additional information should be given to patients and carers regarding the use of carbimazole?
Warn patient or carers to tell doctor immediately if sore throat, mouth ulcers, bruising, fever, malaise, or non-specific illness develops.
What severe reaction is associated with PTU?
Severe hepatic reactions have been reported, including fatal cases and cases requiring liver transplant—discontinue if significant liver-enzyme abnormalities develop.
Can the “block-and-replace” regimen be used for the treatment of hyperthyroidism in pregnancy?
NO; the lowest dose that will control the hyperthyroid state should be used and NO MORE because PTU crosses the placenta and in high doses may cause fetal goiter and hypothyroidism
Is PTU safe in breastfeeding?
Present in breast milk but does not preclude breast-feeding as long as neonatal development is being closely monitored and the lowest effective dose is used
Monitor infant’s thyroid status
Is PTU safe to prescribe in hepatic impairment?
Consider dose reduction due to risk of increased half-life
What are the monitoring requirements for PTU?
Monitor for hepatotoxicity
What additional information should be given to patients and carers regarding PTU?
Patients should be told how to recognise signs of liver disorder and advised to seek prompt medical attention if symptoms such as anorexia, nausea, vomiting, fatigue, abdominal pain, jaundice, dark urine, or pruritus develop.
