Endocrine System

Question 1

What is an example of a rapid-acting insulin?

Answer 1

Insulin aspart (Novorapid)

Question 2

What is an example of a short-acting insulin?

Answer 2

Soluble insulin (Actrapid, Humulin S)

Question 3

What is an example of an intermediate-acting insulin?

Answer 3

Isophane insulin (NPH)

Question 4

What is are two examples of long-acting insulin?

Answer 4

Insulin degludec

Insulin glargine

Question 5

Why can’t you give insulin orally?

Answer 5

It’s a protein so would be digested in the gut, usually given s.c

Question 6

What are some ADRs of insulin?

Answer 6

• Hypoglycaemia

* Lipodystrophy (lipoatrophy and lipohypertrophy) at injection sites

Question 7

What are some DDIs of insulin?

Answer 7

Increase dose if given with systemic steroids

Caution with other hypoglycaemic agents

Question 8

What is a contraindication of insulin?

Answer 8

Renal impairment - risk of hypoglycaemia as insulin is excreted renally

Question 9

What is basal-bolus dosing?

Answer 9

If a young, active person with T1DM has good adherence, can use this method - Taking a rapid-acting insulin e.g. aspart as a bolus post-meals and then a long-acting e.g. glargine basally, throughout the day (at night)

Question 10

Describe the onsets of action and durations of insulin aspart, soluble insulin, isophane insulin and insulin glargine…

Answer 10

• Insulin aspart: 10-20 mins, 3-5 hrs
• Soluble insulin: 30-60 mins, 5-8 hrs
• Isophane insulin: 60-120 mins, 18-24 hrs
• Insulin glargine: 60-90 mins, 20-24 hrs

Question 11

When are dextrose, glucagon and glucose given?

Answer 11

• Dextrose - same as glucose
• Glucagon - diabetic hypoglycaemia, severe hypotension (due to beta-blocker overdose), diagnostic aid
• Glucose - oral glucose tolerance test, to establish gestational diabetes, hypoglycaemia, energy source, water replacement, ketoacidosis management

Question 12

Give an example of a biguanide.

Answer 12

Metformin

Question 13

What is an example of a sulfonylurea?

Answer 13

Gliclazide

Question 14

What is are two examples of thiazolidinediones/glitazones?

Answer 14

Pioglitazone

Rosiglitazone

Question 15

What is the mechanism of action of thiazolidinediones?

Answer 15

PPARy(gamma) receptor agonist - increases insulin sensitisation in muscle and adipose tissue

Question 16

Is there weight gain with the thiazolidinediones?

Answer 16

Yes - due to fat cell differentiation

Question 17

What are some ADRs of thiazolidinediones?

Answer 17

• GI upset
• Fluid retention
• Fracture risk
• Bladder cancer - hence used less often

Question 18

Give two examples of GLP1 analogues.

Answer 18

• Exenatide

* Liraglutide

Question 19

How do GLP1 analogues work?

Answer 19

Incretin mimetics - increase glucose dependent synthesis of insulin secretion from beta-cells by activating the GLP1 receptor and are resistant to degradation by DPP-4

Question 20

When do you use e.g. exenatide?

Answer 20

As an add-on if triple therapy is ineffective

Question 21

What are the ADRs of GLP1 analogues?

Answer 21

• GI upset

* Decreased appetite with weight loss (initially useful if high BMI, but monitor)

Question 22

What are two examples of sodium-glucose co-transporter 2 (SGLT-2) inhibitors?

Answer 22

• Canagliflozin

* Dapagliflozin

Question 23

What are the ADRs of SGLT-2 inhibitors?

Answer 23

• UTI
• Genital infections
• Thirst
• Polyuria

Question 24

What are the DDIs of SGLT-2 inhibitors?

Answer 24

• Antihypertensives

* Other hypoglycaemic agents

Question 25

What are 4 examples of systemic corticosteroids?

Answer 25

* Betamethasone * Dexamethasone * Hydrocortisone * Prednisolone

Question 26

What is the mechanism of action of systemic corticosteroids?

Answer 26

Prevent IL-1 and IL-6 production by macrophages. Inhibit all stages of T cell activation Act like endogenous cortisol (bind to glucocorticoid receptors) - decrease inflammation, reduce immune response, regulate metabolism

Question 27

Give two examples of drug used in HRT?

Answer 27

* Estradiol | * Medroxyprogesterone acetate

Question 28

What is the mechanism of action of estradiol?

Answer 28

Oestrogen steroid hormone - stimulates oestrogen receptors

Question 29

What is the mechanism of action of medroxyprogesterone?

Answer 29

Synthetic progesterone - stimulates progesterone receptors

Question 30

Why is HRT prescribed at menopause?

Answer 30

* Reduces the symptoms of hot flushes/sweats and dyspareunia * Reduces osteoporosis risk

Question 31

What are the risks of using HRT?

Answer 31

* Increased risk of venous thromboembolism (increased if a smoker) * Unopposed oestrogen (ERT) - increased risk of endometrial and cervical cancers * Opposed oestrogen (HRT) - increased risk of breast cancer * Increased risk of stroke

Question 32

What are two examples of anti-oestrogens?

Answer 32

* Clomifene | * Tamoxifen

Question 33

What are clomifene and tamoxifen?

Answer 33

Selective oestrogen receptor modulatiors (SERM)

Question 34

When is clomifene used? How does it work?

Answer 34

To treat anovulation Competes with oestrogen for ER binding. Leads to ovulation through increased production of anterior pituitary hormones

Question 35

When is tamoxifen used? How does it work?

Answer 35

Breast cancer A prodrug, metabolised in the liver to an active metabolite - competes with oestrogen for binding to ER. Causes cells to arrest in the cell cycle

Question 36

How does tamoxifen work differently in breast and endometrial tissue?

Answer 36

In breast tissue - is an ER antagonist | In endometrial tissue - is an ER agonist

Question 37

What are 3 examples of bisphosphonates?

Answer 37

* Alendronic acid * Pamidronate disodium * Zoledronic acid

Question 38

What do bisphosphates do?

Answer 38

Reduce bone turnover (used to treat and as prophylaxis of osteoporosis) - control osteoclast activity

Question 39

What are the ADRs of bisphosphonates?

Answer 39

* Upper GI effects - oesophagitis - educate patient on remaining seated or standing for 30 mins after taking * Hypocalcaemia - check vit D and calcium levels before starting treatment Must be taken on an empty stomach as absorption affected by food, especially milk