Corticosteroids

Question 1

Name a disease which occurs when circulating levels of steroids is too high

Answer 1

Cushing’s disease

Question 2

Name a disease which occurs when circulating levels of steroids is too low

Answer 2

Addison’s disease

Question 3

Describe the HPA axis

Answer 3

• Stress and circadian rhythm influences hypothalamus
• CRH from hypothalamus signals pituitary
• ACTH produced which signals adrenals to produce cortisol
• Cortisol has tissue actions
• Cortisol levels provide negative feedback at pituitary and hypothalamic levels

Question 4

Name 2 main types of steroids

Answer 4

1. Glucocorticoids

2. Mineralocorticoids

Question 5

What is an example of a glucocorticoid?

Answer 5

Hydrocortisone

Question 6

What is an example of a mineralocorticoid?

Answer 6

Aldosterone

Question 7

Give an overview of the function of mineralocorticoids

Answer 7

• Bind to mineralocorticoid receptor expressed in kidney and epithelial cells of colon and bladder
• Regulate electrolyte balance

Question 8

Describe 2 physiological outcomes caused by mineralocorticoids

Answer 8

1. Increased sodium reabsorption in DCT

2. Increased potassium and hydrogen excretion

Question 9

Where are steroid hormone receptors found in the cell?

Answer 9

Cytosol

Question 10

How do activated glucocorticoid receptors identify target genes in the nucleus?

Answer 10

GC receptor dimers bind to specific hormone response elements (HREs) on target genes

Question 11

Name 3 actions of glucocorticoids and drugs used for these purposes

Answer 11

1. Metabolic (hydrocortisone)
2. Anti-inflammatory (prednisolone)
3. Immunosuppressive (dexamethasone)

Question 12

What is the function of the metabolic effects of glucocorticoids?

Answer 12

Protecting glucose dependent tissues from starvation

Question 13

Describe how metabolic effects of glucocorticoids affect the liver

Answer 13

• Decrease glucose uptake
• Decrease glucose utilization
• Increase gluconeogenesis

Question 14

Describe how metabolic effects of glucocorticoids affect muscle

Answer 14

• Decreased protein synthesis

- Increase protein breakdown

Question 15

Name 4 clinical uses of glucocorticoids

Answer 15

1. Replacement therapy for Addison’s disease
2. Anti-inflammatory
3. Autoimmune disease
4. Transplant patients

Question 16

Describe how corticosteroids reduce inflammation

Answer 16

• Suppress all phases of early inflammation
• Decrease number of activated macrophages and T cells
• Decreased IL-1 and IL-2 production
• Decreased transcription of COX-2 and PLA2

Question 17

Describe Addison’s doosease

Answer 17

Primary hypoadrenalism

Question 18

What is the general rule for supplement steroid dose in dentistry for patients using long term steroids?

Answer 18

• Generally do not supplement for routine dental procedures

- May need to supplement for general anaesthetic or implant insertion

Question 19

Name 5 therapeutic uses of steroids in dentistry

Answer 19

1. Oral ulceration
2. Post operative pain
3. Pulp inflammation
4. Pain from TMJ
5. Bell’s Palsy

Question 20

Name 3 oral mucosal lesions which steroids may be used to treat

Answer 20

1. Erosive lichen planus
2. Erythema multiforme
3. Pemphigus

Question 21

Name 3 types of steroidal therapies used for oral ulceration

Answer 21

1. Topical
2. Injection into lesion
3. Systemic

Question 22

Name 2 types of oral surgery steroids will be used post operatively

Answer 22

1. Post impacted 3rd molar removal

2. Post orthognathic surgery

Question 23

How are steroids administered for a patient with TMJ pain?

Answer 23

Intra-articular injecitons

Question 24

Name 4 major side effects of corticosteroid therapy

Answer 24

1. Euphoria
2. Cataracts
3. Increased abdominal fat
4. Poor wound healing

Question 25

How does Cushing's syndrome arise?

Answer 25

Excess circulating glucocorticoids

Question 26

Name 2 treatments for Cushing's disease

Answer 26

1. Metyrapone | 2. Ketoconazole

Question 27

What tends to cause excess glucocorticoids in Cushing's disease?

Answer 27

Increasing circulating levels of GC or ACTH

Question 28

Where are thyroid hormone receptors found?

Answer 28

Cytosol of a cell

Question 29

What ion is required for the release of thyroid hormone?

Answer 29

Iodide

Question 30

How is iodide taken into the body?

Answer 30

Diet from fish, seaweed or dairy

Question 31

Name 4 functions of thyroid hormones

Answer 31

1. Growth and development 2. Calorigenic (heat generating) 3. Metabolic (carbohydrate metabolism) 4. Cardiovascular (increased HR)

Question 32

What is hypothyroidism?

Answer 32

Insufficient production of thyroid hormones

Question 33

What is the treatment for hypothyroidism?

Answer 33

Levothyroxine

Question 34

What are the symptoms of hypothyroidism in babies?

Answer 34

Severely shunted physical and mental growth

Question 35

What is hyperthyroidism?

Answer 35

Excess production of thyroid hormones causing Goitre

Question 36

Name 4 symptoms of hyperthyroidism

Answer 36

1. Bulging eyeballs 2. Muscle weakness 3. Anxiety 4. Increased HR

Question 37

Name 2 pharmacological treatments of hyperthyroidism

Answer 37

1. Thyioureylenes | 2. Potassium perchlorate

Question 38

How does potassium perchlorate function?

Answer 38

Inhibit iodine uptake in thyroid

Question 39

What is the major side effect of thyioureylenes?

Answer 39

Leucopenia