Endocrine Flashcards
What is diabetes insipidus
excess dilute urine = extreme thirst due to too little ADH
hormones in the urine process in a normal person
- hypothalamus produces vasopressin (ADH) - stored in pituitary gland
- ADH released when water in body too low
- ADH retains water in body by reducing amount of water lost through kidneys
= more concentrated urine
hormones in the urine process in diabetes insipidus
- reduced vasopressin so reduced ADH
- kidneys don’t retain as much water
- too much water passed from body = extreme thirst/polyuria
= more dilute urine
Two types of diabetes insipidus
- pituitary (cranial)
- nephrogenic (partial)
What is pituitary (cranial) diabetes insipidus
- lack of vasopressin (ADH) production
- most common type
- Tx = vasopressin or desmopressin
What is nephrogenic (partial) diabetes insipidus
- you have ADH but kidneys don’t respond to it
- Tx = thiazide like diuretic (paradoxical effect)
Desmopressin information
- more potent and longer duration of action than vasopressin
- no vasoconstrictor effect
- side effects = hyponatraemia, nausea
What does too much ADH cause
- body stores too much water = dilutes the salt conc in blood = hyponatraemia
Too much ADH treatment
- fluid restriction
- demeclocycline (blocks renal tubular effect of ADH)
- tolvaptan (vasopressin antagonist)
- avoid rapid correction of hyponatraemia with tolvaptan as it causes osmotic demyelination = serious neurological events
What is diabetes mellitus
- persistent hyperglycaemia
- type 1 = deficient insulin secretion
- type 2 = resistance to action of insulin
- gestational = pregnant
- secondary to medications
Diabetes and fitness to drive
- treatment with insulin = notify DVLA
- assess on awareness of hypoglycaemia - capability of bringing vehicle to a safe stop
Diabetes and group 1 driver rules
- ‘normal’ drivers
-adequate awareness of hypoglycaemia - no more that 1 episode of severe hypo while awake in last 12 months
Diabetes and group 2 driver rules
- HGV/lorry/bus drivers
- report all episodes of severe hypo including in sleep
- full awareness of hypo
- no episodes of severe hypo in last 12 months
- must use glucose meter with sufficient memory to store 3 months of readings
- visual complications = notify DVLA and don’t drive
DVLA advice for diabetics
- tx with insulin = always carry glucose meter and strips
- check glucose 2 hours before and every 2 hours during driving
- glucose always > 5, if < 5 have a snack
- ensure supply of fast-acting carbohydrate in vehicle e.g. glucose tablets, glucose drinks, full sugar soft drinks, sweets, biscuits
Hypoglycaemia whilst driving rules
- considered as < 4mmol/L
1. stop vehicle
2. engine off, remove keys, move from drivers seat
3. eat/drink suitable source of sugar
4. wait 45 minutes after blood glucose back to normal - DONT drive if hypo awareness lost - notify DVLA
what is type 1 diabetes
- insulin deficiency - destroyed b-cells in islets of langerhans
- commonly before adulthood
Features of type 1 diabetes
- hyperglycaemia (>11mmol/L)
- ketosis
- rapid weight loss
- BMI<25
- age < 50
- family history of autoimmune disease
Type 1 diabetes blood glucose monitoring frequency and targets
- at least QDS including before meals and bed
- on waking = 5-7
- fasting before meals/other times of day = 4-7
- 90 mins after eating = 5-9
- when driving = > 5
Type 1 diabetes insulin regimen
- basal-bolus regimen
- basal = long/intermediate
- bolus = short/rapid - before meals
name the long acting insulins
- detemir - BD
- glargine - OD
- degludec - OD
name the rapid acting insulins
- asparte
- lispro
- glulisine
Name intemediate acting insulin
- biphasic isophane
- biphasic asparte/lispro (isophane + short acting)
what is biphasic insulin
- short acting mixed with intermediate - 1-3x a day
Long acting insulin onset and duration
- onset = 2-4 days to reach steady state
- duration = 36 hours
Name soluble insulins
- human + bovine/porcine
Soluble insulin details
- 15-30 minutes before meals
- onset = 30 to 60 minutes
- peak action = 1-4 hours
- duration = up to 9 hours
Rapid insulin details
- immediately before meals
- onset < 15 minutes
- duration = 2-5 hours
Intermediate insulin details
- onset = 1-2 hours
- peak affect = 3-12 hours
- duration = 11-24 hours
What is used for disabling/uncontrolled hyperglycaemia
continuous subcutaneous insulin infusion (insulin pump)
When to increase/decrease insulin
- increase insulin when - infection, stress, trauma
- reduce insulin when - physical activity, intercurrent illness, reduced food, reduced renal function, thyroid disease, addisons, coeliacs
Insulin administration
- inactivated by GI enzymes - give subcut into fat e.g. abdo (fastest absorption), outer thigh, buttocks (slower absorption)
- rotate site - lipohypertrophy = erratic absorption of insulin
What is type 2 diabetes
- insulin resistance later in life
- pre diabetes = HbA1c: 42-47
- diabetes = 48 mol/mol
- offer lifestyle advice 1st line
Type 2 diabetes treatment (low CVD risk)
- assess HbA1c, kidney function and CVD risk
1. Metformin
2. + DPP-41 (gliptin), pioglitazone, sulfonylurea or SGLT2i (flozin)
3. triple therapy (add/swap)
4. specialised e.g. insulin, GLP1 agonist
Type 2 diabetes treatment (high CVD risk)
- assess HbA1c, kidney function, CVD risk (high risk = established attherosclerotic CVD/HF or QRISK > 10%)
1. metformin
2. SGLTi (flozin)
3. +DPP-4i (gliptin), pioglitazone or sulfonylurea
4. triple therapy (add/swap) - if at any point develops high risk - consider SGLT2i
Type 2 diabetes metformin resistant treatment
- if due to GI side effects - use MR prep
- assess HbA1c, kidney function, CVD risk
1. DPP-4i (gliptin), pioglitazone, sulfonylurea OR SGLT2i (flozin - in high CVD risk)
2. DPP-4i + pioglitazone OR DPP-41 + sulfonylurea OR pioglitazone + sulfonylurea
3. insulin - aim for individually agree threshold for HbA1c through tx
Diabetic complications - CVD treatment
- low dose statin (T1DM, age > 40, diabetes > 10 yrs, nephropathy, other CVD)
- ACEi to reduce CVD risk
Diabetic complications - diabetic nephropathy
- nephropathy causing proteinurea = ACEi (including black and >55)/ARB
- ACEi/ARB potentiate hypoglycaemic effect of anti diabetic drugs/insulin
Diabetic complications - diabetic neuropathy
- painful peripheral neuropathy
- anti-depressant, gabapentin, pregabalin
Diabetic complications - diabetic foot
- treat pain
- manage infection
Diabetic complications - autonomic neuropathy
- treat diarrhoea with codeine or tetracyclines
Diabetic complications - neuropathic postural hypotension
- increase salt intake
- OR fludrocortisone
Diabetic complications - gustatory sweating
- antimuscarinic (propantheline bromide)
Diabetic complications - erectile dysfunction
- sildenafil
Diabetic complications - visual impairment
- annual eyes test - free
Metformin (biguanide) MoA
reduces gluconeogenesis and increases peripheral utilisation of glucose
Metformin side effects
- lactic acidosis (DONT use if eGFR < 30)
- GI effects (increase dose slowly/MR)
- reduces vitamin B12
- hold if AKI
Sulphonylureas MoA
augments insulin secretion
Name short acting and long acting sulphonylureas
- short-acting: gliclazide, tolbutamide
- long-acting: glibenclamide, glimepiride
Sulphonylureas side effects
- prolonged/fatal hypoglycaemia (avoid elderly) (target - 7%)
- avoid in acute porphyrias
- avoid in hepatic and renal failure
Pioglitazone MoA
reduces peripheral insulin resistance
Pioglitazone side effects
- avoid in history of heart failure
- increase risk of bladder cancer - review in 3-6 months, report haematuria, dysuria, urinary urgency
- increased risk of bone fractures and liver toxicity - report NV, abdo pain, fatigue, dark urine
Dipeptidylpeptidase-4 inhibitors MoA
- alogliptin, linagliptin, saxagliptin, sitagliptin, vildagliption (new hepatotoxic)
- inhibits DPP-4 to increase insulin secretion and lower glucagon secretion
DPP-4i side effects
cause pancreatitis - stop if persistent, severe abdo pain
Sodium Glucose Co-transporter 2 inhibitors MoA
- canagliflozin, dapagliflozin, empagliflozin
- inhibits SGLT2 in renal proximal convoluted tubule
SGLT2i MHRA warnings
- life threatening/fatal DKA - monitor ketones
- fourniers gangrene (necrotising fasciatis of genitalia/perineum)
- canagliflozin: lower limb amputation (mainly toes)