Hypo/hyper thyroidism

Question 1

What is hypothyroidism?

Answer 1

thyroid gland unable to produce hormones because of

iodine deficiency or abnormality of gland itself.

Question 2

What are the symptoms of hypothyroidism?

Answer 2

Fatigue/lethargy, depression, impaired, concentration, poor memory, weight gain with decreased appetite, cold intolerance, muscle pain and weakness, constipation, menstrual irregularities, dry skin, and reduced body and scalp hair (such as sparse eyebrows), thyroid pain Symptoms and signs
non-specific and gradual onset, vague in the early stages; sometimes asymptomatic, especially in the elderly patients with relatives/ friends with hypothyroidism often blame their own fatigue, low mood and weight gain on it!

Question 3

How do thyroid hormones present in blood plasma?

Answer 3

free T4 and free T3 AND
TSH rises markedly; starts early in the course of thyroid failure –
even before overt clinical signs

Question 4

Which drugs can cause hypothyroidism?

Answer 4

propylthiouracil, amiodarone, gluccocorticoids, furosemide, salicylates, NSAIDs, heparin, oestrogen, tamoxifen, phenytoin, rifampicin, carbamazepine

Question 5

What is the interaction between levothyroxine and diabetes?

Answer 5

Treatment with levothyroxine can increase blood sugar levels

Question 6

How is levothyroxine initiated in adults <50 with no heart disease?

Answer 6

start with low dose oral levothyroxine (50mcg daily), increased in 3-4 week intervals in increments of 25-50mcg until serum t4 and TSH is normal

Question 7

How is levothyroxine initiated in adults over 50, or adults with heart disease/severe hypothyroidism?

Answer 7

lower dose (12.5-25), increasing In increments every 4 weeks by 25 micrograms.

Question 8

What can happen if levothyroxine is initiated too quickly?

Answer 8

severe angina, MI, heart failure, cardiac arrythmias

Question 9

What is hyperhtyroidism?

Answer 9

TSH suppressed to subnormal levels

Question 10

What drug can be prescribed for rapid relief of Hyperthyroidism?

Answer 10

BB - Propanolol 10-40mg T/QDS

Question 11

How can hyperthyroidism be treated?

Answer 11

Antithyroid drugs, thyroid ablation via surgery or radioactive iodine

Question 12

Which measurements must be taken prior to starting treatment for hyperthyroidism?

Answer 12

full blood count, white cell count and differential

liver function tests

Question 13

What is first/second line for hyperthyroidism?

Answer 13

carbimazole/propylthiouracil

Question 14

How should hyperthyroid drugs be started?

Answer 14

initial dose (given once daily) takes 1-2 weeks for therapeutic 
effect to start; continue for 4–8 weeks until person becomes 
euthyroid (based on free thyroxine [FT4] level)

Question 15

What are the main problematic effects of carbimazole/propylthiouracil?

Answer 15

neutropenia and agranulocytosis
Hence counselling advice for patients on carbimazole
or propylthiouracil -
STOP treatment and contact doctor immediately if develop
fever, sore throat, mouth ulcers, or other symptoms of
infection

Question 16

What is thyrotoxic crisis?

Answer 16

Rare medical emergency, may occur after trauma, childbirth, infection, stroke, diabetic ketoacidosis, or surgery in people with untreated or poorly treated hyperthyroidism
Typical features of thyroid storm include:
– Severe tachycardia (greater than 140 heart beats per
minute), atrial fibrillation, and congestive heart failure
– Fever (temperature greater than 38.5°C)
– Dehydration, diarrhoea and vomiting
– Jaundice
– Agitation, delirium, psychosis, and coma

Question 17

How should thyrotoxic crisis be managed?

Answer 17

IV fluids
propranolol and hydrocortisone
oral iodine solution
carbimazole (or propylthiouracil)