what are the Signs and symptoms of hyperthyroidism
- goitre ( swelling of the thyroid gland that causes a lump in the front of the neck)
- hyperactivity
- disturbed sleep
- fatigue
- palpitations
- anxiety
- heat intolerance
- increased appetite with unintentional weight loss
- diarrhoea
what is hyperthyroidism
excessive production and secretion of thyroid hormones leading to thyrotoxicosis (an excess of circulating thyroid hormones)
what are the risk factors of hyperthyroidism
- smoking
- a family history of thyroid disease
- co-existent autoimmune conditions
- low iodine intake
what laboratory results show hyperthyroidism
- Low TSH (thyroid stimulating hormone)
and - High FT4 ( free thyroxine) and FT3 (free triiodothyronine)
what is the non-drug treatment for hyperthyroidism
Radioactive iodine or surgery (e.g thyroidectomy or hemithyroidectomy which involves removing part of/or all of the thyroid gland)
note drug treatment for hyperthyroidism must be carried out whilst waiting for surgery
what is the first choice antithyroid drug for hyperthyroidism
First choice: Carbimazole
- Propylthiouracil considered for those in whom carbimazole is unsuitable
what are the main side effects associated with taking carbimazole for hyperthyroidism
- bone marrow suppression (Neutropenia and agranulocytosis)
- risk of acute pancreatitis
what are the symptoms that a patient taking carbimazole should report that can indicate bone marrow suppression
report symptoms and signs suggestive of infection, especially sore throat
*note: A white blood cell count should be performed if there is any clinical evidence of infection and stop treatment if there is neutropenia - low white blood cell count)
can carbimazole be used for pregnant women with hyperthyroidism
- Women of childbearing potential should use effective contraception during treatment with carbimazole
- Carbimazole should only be considered in pregnancy after a thorough benefit-risk assessment (+ use lowest effective dose)
can Propylthiouracil be given for pregnant women with hyperthyroidism
yes it can be given but the blocking-replacement regimen is not suitable. Use lowest effective dose
note: the blocking-replacement regimen is using a high dose of antithyroid drugs (ATD) with levothyroxine (L-T4
what Propylthiouracil regimen is not suitable during pregnancy
the blocking-replacement regimen is not suitable
note: the blocking-replacement regimen is using a high dose of antithyroid drugs (ATD) with levothyroxine (L-T4
why should you counsel patients taking Propylthiouracil on how to recognise signs of liver disorder
what are the signs of liver disorder
because propylthiouracil can cause hepatotoxicity
signs of liver disorder are:
- anorexia
- nausea + vomiting
- abdominal pain
- Jaundice
- dark urine
- pruritus (itchy skin)
what is hypothyroidism
the underproduction and secretion of thyroid hormones
what are the symptoms of hypothyroidism
- menstrual irregularities
- depression
- dry skin
- intolerance to the cold
- reduced body and scalp hair
- fatigue
- weight gain
- constipation
what laboratory results indicate hypothyroidism
- High TSH (thyroid stimulating hormone)
and - Low FT4 (free thyroxine) and FT3 (free triiodothyronine)
what are the treatment options for hypothyroidism
first line: levothyroxine
- Liothyronine (either alone or in combination with levothyroxine) but it is not routinely recommended, it is more ideal for severe hypothyroid emergencies
what are the symptoms of thyrotoxicosis
- increased heart rate (more than 140bpm)
- tachycardia, arrhythmias
- heat intolerance
- diarrhoea (+ n&v, dehydration)
- seizures (+ psychosis)
what is the MHRA advice for patients who experience symptoms when switching between different levothyroxine products
- if a patient reports symptoms after changing to a different tablet of levothyroxine, a thyroid function test should be considered. If a patient is persistently symptomatic, prescribe a specific brand of levothyroxine that is well tolerated for patient
- if still poor control of thyroid function despite adhering to specific levothyroxine tablet, consider prescribing levothyroxine in an oral solution formulation.
what can decrease the absorption of levothyroxine
Food, including dietary fibre, milk, soya products, and coffee, might decrease the absorption of levothyroxine
what happens if the metabolism increases too rapidly after initiating levothyroxine or liothyronine
how do you resolve this
may get hyperthyroidism symptoms such as: diarrhoea, nervousness, rapid pulse, insomnia, tremors
To resolve this:
reduce dose or withhold for 1–2 days and start again at a lower dose.
can levothyroxine be used during pregnancy
Yes. Levothyroxine requirement may increase during pregnancy.
Need to make sure mother is stable on levothyroxine as Excessive or insufficient maternal thyroid hormones can harm fetus
why should a patient be monitored if they are taking liothyronine and they switch to a different brand
because brands of liothyronine without a UK licence may not be bioequivalent
name some medications that can affect thyroid function
- amiodarone (can cause hypothyroidism or hyperthyroidism)
- lithium (can cause hypothyroidism)
- iodine containing medication (cause cause hypothyroidism or hyperthyroidism)
