Endocrinology Flashcards
Mr Y is due to undergo planned surgery in two weeks. He has come to see you for advice re metformin..
Stop at time of surgery under general, spinal or epidural anaesthesia.
Continue at least 48 hours after surgery when renal function is stable
What is the onset of action of rapid-acting insulin?
15 minutes
What are the different rapid-acting insulins?
Insulin aspart
Insulin glulisine
Insulin lispro
What is the onset of action of soluble insulin (SC)?
30 - 60 minutes
Give an example of an intermediate- acting insulin
Isophane insulin
List counselling points with SC insulin administration
Inject into abdominal wall, thigh, upper arm or gluteal region
Injection sites should be rotated within the same area to reduce risk of lipodystrophy and cutaneous amyloidosis
What do biphasic insulins contain?
A mix of intermediate-acting and short-acting insulin (varying from 15-50%)
Give examples of biphasic insulins (brands)?
Humulin M3
Novomix 30
Humalog Mix 50
What is the duration of action of long-acting insulin?
Upto 36 hours
What are examples of long-acting insulins?
Insulin detemir
Insulin glargine
Insulin degludec
Give examples of brands of long-acting insulin
Levemir
Lantus
Tresiba
Give examples of brands of rapid-acting insulins
Fiasp
Novorapid
Apidra
Humalog
Lyumjev
Metformin exerts its action by…
Decreasing gluconeogenesis
Increasing peripheral utilisation of glucose
Which antidiabetic drug can be used to aid weight reduction, normalise menstrual cycle and improve hirsutism?
Metformin
Patients must report symptoms of dysuria or haematuria with which anti-diabetic drug?
Pioglitazone - MHRA advice re bladder cancer risk
What is the mechanism of action of sulphonylureas?
Stimulates insulin secretion from beta-cells of the islets of Langerhans
This means that residual pancreatic beta-cell activity is required.
Give examples of sulphonyureas?
Gliclazide
Glibenclamide
Glimepiride
Glipizide
Tolbutamide
What are the signs and symptoms of hypothyroidism?
Weight gain, cold intolerance, constipation
What are the signs and symptoms of hyperthyroidism?
Weight loss, heat intolerance, diarrhoea goitre (lump or swelling in front of neck), fine tremor, palpitations
What does high T3 and T4, low TSH mean?
primary hyperthyroidism
What does the TFTs of someone with primary hypothyroidism look like?
High TSH, low T4 and T3
What are the unlicensed use of metformin
PCOS (dose titrated as it is for diabetes)
T2DM in children aged 8-9
When should metformin be avoided ?
If eGFR is less than 30ml.min/1.72m2
What are common s/e of metformin
Lactic acidosis (discontinue treatment)
GI discomfort - can be resolved using modified release preparations, symptoms usually worst on initiation
Vitamin B12 deficiency
What dietary interactions are there with levothyroxine?
Food, including dietary fibre, milk, soya products, and coffee, might decrease the absorption of levothyroxine.
Counselling advice for levothyroxine?
-Take before breakfast or the first meal of the day.
-Administration should be of levothyroxine should be at least 4 hours apart if taking antacids, calcium salts, cimetidine, oral iron, sucralfate, colestipol, polystyrene sulphonate resin and cholestyramine.
-Avoid caffeine
What is the DVLA advice around glucose monitoring for drivers with diabetes?
Blood-glucose concentration should be checked no more than 2 hours before driving and every 2 hours while driving
What is the minimum blood-glucose concentration required for driving?
Should be at least 5 mmol/litre
When is HbA1c target 53mmol/mol?
-Patient prescribed a single drug associated with hypoglycaemia (such as a sulfonylurea).
-When two or more antidiabetic drugs are prescribed
Which sulfonylureas are long-acting?
glibenclamide, chlorpropamide, glimepiride
List microvascular complications of T2DM
Retinopathy
Neuropathy
Nephropathy
List the macrovascular complications of T2DM
Stroke
MI
Peripheral arterial disease
How do systemic corticosteroids work?
2 classes:
Glucocorticoids - reduce inflammatory response
Mineralocorticoids - influence sodium and water retention
Diabetes, osteoporosis and psychiatric reastions are side-effects of which class of steroids?
Glucocorticoids
Give examples of corticosteroids with primarily glucocorticoid activity
Betamethasone
Dexamethasone
Prednisolone
Deflazacort
- these are all more suitable for long-term use for disease suppression as less likely to cause fluid retention
Give examples of corticosteroids with primarily mineralocorticoid activity
Fludrocortisone
Hydrocortisone (equal activity)
Important counselling points for GLP-1 agonists?
Patients should recongise and report symptoms of acute pancreatitis
At what HbA1c value should treatment be intensified?
58mmol/mol or greater (if single antidiabetic agent used)
What class of medication is repaglinide in and explain briefly its pharmacokinetics.
Meglitinide
Have a rapid onset of action and short duration of activity (ideal for use around mealtimes)
Which sulphonylureas are safer in elderly patients?
Short-acting such as gliclazide and tolbutamide
How can you use repaglinide for the management of diabetes?
By itself (monotherapy) or in combination with metformin ONLY.
What is the target HbA1c for T1DM?
48mmol/mol or less
What should blood glucose levels be for T1DM before meals
4–7 mmol/litre
What are common signs and symptoms of DKA?
Palpitations
Nausea and vomiting
Sweating
Thirst
Blurred vision
Leg cramps
Fruity smell on breath
How do you manage hypoglycaemia?
symptoms of hypo with blood-glucose greater than 4mmol/L - give normal meal or small carbohydrate snack
blood-glucose <4mmol/L, with or without symptoms and who is conscious and able to swallow - give glucose 40% gels, Lift glucose liquid, pure fruit juice. Repeat after 15 mins (max 3 times).
hypoglycaemia where patient is unconscious should be treated with glucagon IM or glucose 10% IV infusion
Long-acting carboyhdrate should be given when patient has recovered in all cases.
When is glucagon ineffective?
In patients whos liver glycogen is depleted e.g. anyone who has fasted for a prolonged time or has adrenal insufficiency.
Glucagone may be ineffective in alcohol-induced hypos.
How do you manage hypos caused by sulphonylureas?
Glucagon may be less effective, use IV glucose instead.
monitor blood glucose levels for at least 24-48hours.
hypoglycaemia caused by a sulphonylurea may persist for 24-36hours following last dose.
Which GLP-1 agonist has a special contraindication?
Liraglutide - contraindicated in IBD, and diabetic gastroparesis
Which SGLT2i has an additional MHRA warning that others in the same class dont have? What is the warning??
canagliflozin - increased risk of lower limb amputation (toes).
Consider stopping canagliflozin if patient develops a significant lower limb complication (skin ulcer, osteomyelitis or gangrene)
What should drivers with diabetes do if their blood glucose is less than 4mmol/L or they have symptoms of hypo?
Stop the car. Do not drive.
Resolve hypoglycaemia, then wait at least 45 minutes after blood glucose is 5mmol/L to start driving again.
What are the risks associated with abrupt withdrawal of systemic corticosteroids
Abrupt withdrawal can lead to acute adrenal insufficiency, hypotension or death.
Withdrawal can also be associated with:
Fever
Myalgia
Arthralgia
Rhinitis
Conjunctivitis
Painful itchy skin nodules
Weight loss.
When should you consider gradual withdrawal of corticosteroids?
When patients disease is unlikely to relapse and have:
(i) received more than 40 mg prednisolone (or equivalent) daily for more than 1 week
(ii) been given repeat doses in the evening
(iii) received more than 3 weeks’ treatment
(iv) recently received repeated courses (particularly if taken for longer than 3 weeks)
(v) taken a short course within 1 year of stopping long-term therapy
(vi) other possible causes of adrenal suppression.
What sort of symptoms should patients be advised to report with vildagliptin?
(THIS APPLIES ONLY TO VILDAGLIPTIN, not other gliptins)
signs of liver toxicity:
Dark urine, nausea, vomiting, abdominal pain, fatigue, jaundice
Which antidiabetic drugs carry risk of acute pancreatitis?
Gliptins (DPP4 inhibitors)
GLP-1 agonists
What are the two MHRA alerts around the use of pioglitazone?
Bladder cancer
Cardiovascular safety - pioglitazone should not be used in HF or history of HF (the drug increases water retention which worsens HF). Should be avoided in patients with previous MI
What are the symptoms of rapid metabolism of levothyroxine?
What can be done to help this?
Rapid metabolism causes: diarrhoea, nervousness, rapid pulse, insomnia, tremors and sometimes anginal pain where there is latent myocardial ischaemia.
Reduce dose or withhold for 1–2 days and start again at a lower dose.
