Endocrine System Flashcards
What is an example of a rapid-acting insulin?
Insulin aspart (Novorapid)
What is an example of a short-acting insulin?
Soluble insulin (Actrapid, Humulin S)
What is an example of an intermediate-acting insulin?
Isophane insulin (NPH)
What is are two examples of long-acting insulin?
Insulin degludec
Insulin glargine
Why can’t you give insulin orally?
It’s a protein so would be digested in the gut, usually given s.c
What are some ADRs of insulin?
- Hypoglycaemia
* Lipodystrophy (lipoatrophy and lipohypertrophy) at injection sites
What are some DDIs of insulin?
Increase dose if given with systemic steroids
Caution with other hypoglycaemic agents
What is a contraindication of insulin?
Renal impairment - risk of hypoglycaemia as insulin is excreted renally
What is basal-bolus dosing?
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)
Describe the onsets of action and durations of insulin aspart, soluble insulin, isophane insulin and insulin glargine…
- 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
When are dextrose, glucagon and glucose given?
- 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
Give an example of a biguanide.
Metformin
What is an example of a sulfonylurea?
Gliclazide
What is are two examples of thiazolidinediones/glitazones?
Pioglitazone
Rosiglitazone
What is the mechanism of action of thiazolidinediones?
PPARy(gamma) receptor agonist - increases insulin sensitisation in muscle and adipose tissue
Is there weight gain with the thiazolidinediones?
Yes - due to fat cell differentiation
What are some ADRs of thiazolidinediones?
- GI upset
- Fluid retention
- Fracture risk
- Bladder cancer - hence used less often
Give two examples of GLP1 analogues.
- Exenatide
* Liraglutide
How do GLP1 analogues work?
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
When do you use e.g. exenatide?
As an add-on if triple therapy is ineffective
What are the ADRs of GLP1 analogues?
- GI upset
* Decreased appetite with weight loss (initially useful if high BMI, but monitor)
What are two examples of sodium-glucose co-transporter 2 (SGLT-2) inhibitors?
- Canagliflozin
* Dapagliflozin
What are the ADRs of SGLT-2 inhibitors?
- UTI
- Genital infections
- Thirst
- Polyuria
What are the DDIs of SGLT-2 inhibitors?
- Antihypertensives
* Other hypoglycaemic agents
What are 4 examples of systemic corticosteroids?
- Betamethasone
- Dexamethasone
- Hydrocortisone
- Prednisolone
What is the mechanism of action of systemic corticosteroids?
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
Give two examples of drug used in HRT?
- Estradiol
* Medroxyprogesterone acetate
What is the mechanism of action of estradiol?
Oestrogen steroid hormone - stimulates oestrogen receptors
What is the mechanism of action of medroxyprogesterone?
Synthetic progesterone - stimulates progesterone receptors
Why is HRT prescribed at menopause?
- Reduces the symptoms of hot flushes/sweats and dyspareunia
- Reduces osteoporosis risk
What are the risks of using HRT?
- 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
What are two examples of anti-oestrogens?
- Clomifene
* Tamoxifen
What are clomifene and tamoxifen?
Selective oestrogen receptor modulatiors (SERM)
When is clomifene used? How does it work?
To treat anovulation
Competes with oestrogen for ER binding. Leads to ovulation through increased production of anterior pituitary hormones
When is tamoxifen used? How does it work?
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
How does tamoxifen work differently in breast and endometrial tissue?
In breast tissue - is an ER antagonist
In endometrial tissue - is an ER agonist
What are 3 examples of bisphosphonates?
- Alendronic acid
- Pamidronate disodium
- Zoledronic acid
What do bisphosphates do?
Reduce bone turnover (used to treat and as prophylaxis of osteoporosis) - control osteoclast activity
What are the ADRs of bisphosphonates?
- 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
