W5 Thyroid Diseases- clinical management (GW)

Question 1

Definition of Hypothyroidism?

Answer 1

• 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

Question 2

Normal thyroid levels for T3, T4 and TSH (for info)

Answer 2

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)

Question 3

Hypothyroidism symptoms?

Answer 3

• 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

Question 4

Risks factors for hypothyroidism?

Answer 4

*Being a woman
*Diabetes
*Obesity
*Thyroid surgery (thyroidectomy)
*Intake of certain medications
*Autoimmune disease
*Hereditary
*Old age

Question 5

Complications of Hypothyroidism?

Answer 5

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

Question 6

Hypothyroidism- How is it diagnosed?

Answer 6

*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

Question 7

Hypothyroidism
First line- Levothyroxine
MHRA/CHM advice?
C/I?
S/E?
Food and lifestyle?
Cautions?
Administration?

Answer 7

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

Question 8

Hyperthyroidism definition?

Answer 8

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

Question 9

Hyperthyroidism- Symptoms?

Answer 9

*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

Question 10

Hyperthyroidism- Diagnosis

Answer 10

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

Question 11

Hyperthyroidism
What is the first-line treatment?
second-line?

Answer 11

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

Question 12

Thyrotoxicosis
What is it?
Most common cause?

Answer 12

• 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.

Question 13

Thyrotoxicosis Clinical Features?

Answer 13

• 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)

Question 14

Thyrotoxicosis Management? (4)

Answer 14

• β-Blockers e.g. propranolol: symptomatic relief from the
  typical adrenergic symptoms (palpitations, tachycardia, tremor).
• Block and Replace: Carbimazole + Levothyroxine
• Radioiodine
• Surgery

Question 15

Complications of Thyrotoxicosis?

Answer 15

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

Question 16

Antithyroid drugs:
What is Block and replace?

Answer 16

Block and replace: carbimazole is taken to stop the thyroid gland producing thyroid hormone; and
levothyroxine is taken to replace the thyroid hormone the body would normally produce.

Block and replace must not be used in pregnancy as the high doses of antithyroid drugs cross the placenta
and can cause the baby to develop an underactive thyroid.
Block and replacement therapy is usually given for 18 months