W5 Thyroid Diseases- clinical management (GW) Flashcards
Definition of Hypothyroidism?
- Hypothyroidism (underactive thyroid gland), is a clinical disorder, and it means that the thyroid gland is not generating sufficient thyroid hormones as per the body’s requirements.
- The thyroid gland releases thyroid hormones into the body that control how your body utilises energy.
- In the case of hypothyroidism, the body’s functions slow down
Normal thyroid levels for T3, T4 and TSH (for info)
T3 - 100 – 200 nanograms per decilitre of blood (ng/dL)
T4 - 5 – 12 micrograms per decilitre of blood (mcg/dL)
TSH - 0.4 – 4.0 milli-international units per litre (mIU/L)
Hypothyroidism symptoms?
- Increased fatigue
- Weight gain
- Hair loss, dry skin,
- Constipation, nausea
- Painful, prolonged menstruation
- Irritability , anxiety, depression, insomnia
- Inc BP, cholesterol
- Chills, convulsions
- Enlarged thyroid gland
- Swollen face, swelling of the eye socket, rough deep or hoarse voice
- Paresthesia, muscle cramps
- Slow HR, weakness
Risks factors for hypothyroidism?
*Being a woman
*Diabetes
*Obesity
*Thyroid surgery (thyroidectomy)
*Intake of certain medications
*Autoimmune disease
*Hereditary
*Old age
Complications of Hypothyroidism?
If hypothyroidism is left untreated, it can lead to a number of health problems, like-
*Goitre
*Cardiovascular problems
*Birth defects
*Infertility
*Mental health issues
*Myxoedema
*Peripheral neuropathy
*Trouble breathing
*Neuromuscular dysfunction
Hypothyroidism- How is it diagnosed?
*Symptoms
*Medical history
*Physical examination: look for symptoms such as dry skin and hair, hoarse voice, droopy eyelids, swollen
face or a slower heart rate.
*Blood tests: T3, T4, TSH (Called TFTs)
*Imaging tests: Thyroid scan, radioactive iodine uptake test, or ultrasound scan
Hypothyroidism
First line- Levothyroxine
MHRA/CHM advice on brand?
C/I?
S/E?
Food and lifestyle?
Cautions?
Administration?
Levothyroxine: new prescribing advice for patients who experience symptoms on switching between different levothyroxine products - stick to same brand if its working
CI: thyrotoxicosis
S/E: if metabolism increases too rapidly
(diarrhoea, nervousness, rapid pulse, anginal pain, tremors, etc.), reduce dose or withhold for 1-2 days and start again at a lower dose
Food & lifestyle: Food, including dietary fibre, milk, soya products, and coffee, might decrease the absorption of
levothyroxine
Cautions:
* Cardiovascular disorders
* Diabetes (dose of anti-diabetic drugs or insulin may need to be increased)
* Baseline ECG is valuable because changes induced by hypothyroidism can be confused with ischaemia
Administration:
* Dose to be taken preferably 30–60 minutes before breakfast, caffeine-containing liquids (e.g. coffee, tea), or other medication.
* Give the same brand.
Monitor TSH, T3 and T4 at baseline, every 3 months until stabilised and then annually
Hyperthyroidism definition?
Hyperthyroidism (overactive thyroid gland), is a clinical disorder, and it means that the thyroid gland is generating too much thyroid hormone as per the body’s requirements.
* The thyroid gland releases thyroid hormones into the body that control how your body utilises energy.
* In the case of hyperthyroidism, the body’s functions speeds up
Hyperthyroidism- Symptoms?
*increased sweating and feeling hot
*feeling like your heart is racing or is beating irregularly
*hand tremors
*anxiety, nervousness, and irritability
*weight loss despite normal or even increased appetite
*frequent bowel movements or diarrhoea
*difficulty sleeping
*hair loss
*changes in menstrual periods (lighter and/or less frequent)
*trouble swallowing or fullness in the neck
*increased or decreased energy level
*pain behind the eyes and/or swelling or bulging of eyes (for autoimmune thyroid dysfunction only)
* fragile fingernails, shaking hands
Hyperthyroidism- Diagnosis
Perform a physical exam to:
* Examine the thyroid for enlargement or nodules.
* Look for signs of too much thyroid hormone like fast heart rate, shakiness/tremor of the hands, warm and moist skin.
* Look for signs of thyroid eye disease like eye redness, swelling, or bulging of the eyes.
* Check bloods for the level of thyroid hormones (TSH, T4 and T3) and thyroid antibody levels (Thyroid stimulating immunoglobulin (TSI), thyrotropin receptor antibodies (TRAB), and/or Thyroid Peroxidase (TPO) antibodies).
* Lab test results in hyperthyroidism usually show high T4 and/or T3 and low TSH.
*Order imaging tests like thyroid ultrasound or nuclear medicine scans which can help determine why your thyroid is making too much thyroid hormone
Hyperthyroidism
What is the first-line treatment?
second-line?
non-drug treatment?
Carbimazole (imidazole/thionamide)
Propylthiouracil (anti-thyroid)
Carbimazole:
Important safety information:
Neutropenia and agranulocytosis: bone
marrow suppression, report signs of infection, sore throat, mouth ulcers, bruising, fever
MHRA/CHM advice:increased risk of
congenital malformations; strengthened advice on contraception - consider use only after a thorough benefit-risk assessment
MHRA/CHM advice: Carbimazole: risk of acute pancreatitis
Propylthiouracil
Alternative treatment in hyperthyroidism
* Side-effects: bone-marrow disorders, agranulocytosis
* Severe hepatic reactions- discontinue if significant liver-enzyme abnormalities develop, signs of liver disorder: anorexia, nausea, vomiting, fatigue, abdominal pain, jaundice, dark urine or pruritus
Non-drug treatment
* Radioactive iodine or surgery (total thyroidectomy) in cases of Grave’s disease or toxic nodular goiter
Thyrotoxicosis
What is it?
Most common cause?
- Thyrotoxicosis = excess thyroid hormone action
- Hyperthyroidism is a subset of thyrotoxicosis
= thyroid hormone synthesis and secretion by the thyroid gland - The most common cause of thyrotoxicosis is Graves’ disease, an autoimmune condition
-> excess production of thyroid hormones. - The physiological regulation of the HPT (Hypothalamus/ Pituitary/ Thyroid) axis is lost in thyrotoxicosis.
Thyrotoxicosis Clinical Features?
- Thin and brittle hair
- Warm and moist skin
- Irregular or fast heart rate
- Fine tremor
- Brisk reflexes
- Palmar erythema
- Lid lag and lid retraction
- Goitre (enlargement of the neck due to an enlarged thyroid gland)
Thyrotoxicosis Management? (4)
- β-Blockers e.g. propranolol: symptomatic relief from the
typical adrenergic symptoms (palpitations, tachycardia, tremor). - Block and Replace: Carbimazole + Levothyroxine
- Radioiodine
- Surgery
Complications of Thyrotoxicosis?
Thyroid storm: (thyrotoxicosis in its exaggerated form)
* Palpitations
* Tachycardia (often >140 beats per minute)
* Tremor
* Nausea and vomiting
* Abdominal pain
* Reduced level of consciousness
* Confusion/agitation
* Seizures
- Cardiac complications: AF, HF, angina
