Chapter 6: Endocrine Flashcards
What is diabetes insipidus?
Where large amounts of dilute urine are produced which causes extreme thirst
2 types of diabetes insipidus?
- cranial = vasopressin or desmopressin: the hypothalamus does not make enough ADH
- nephrogenic = thiazide diuretics; paradoxical effect: the kidneys do not respond to ADH
What is desmopressin?
Desmopressin is a more potent analogue of vasopressin with a longer duration of action and no vasoconstrictor effects
How does desmopressin work?
Desmopressin works by reducing the amount of urine produced in the body at night by the kidneys. This means that the bladder then fills with less urine during the night. Desmopressin is usually taken at bedtime
What is vasopressin?
vasopressin, also called antidiuretic hormone, hormone that plays a key role in maintaining osmolality (the concentration of dissolved particles, such as salts and glucose, in the serum) and therefore in maintaining the volume of water in the extracellular fluid (the fluid space that surrounds cells).
What is desmopressin used for ?
- diabetes insipidus
- nocturnal enuresis
Desmopressin side effects?
- hyponatrarmic convulsions
What does sydrome of inappropriate antidiuretic hormone secretion cause?
Causes hyponatraemia caused by inappropriate secretion of ADH
What should be done if fluid restriction does not correct hyponatraemia?
- demeclocycline: blocks renal tubular effect of ADH
- tolvaptan: vasopressin antagonist
*Avoid rapid correction of hyponatraemia: causes osmotic demyelination of neurones; serious CNS effects
What are corticosteroids uses?
- inlfammatory long-term diseases
- immunosuppressant
Corticosteroids ?
- betamethasone
- deflazcort
- dexamethasone (palliative care; anorexia/raised intracranial pressure)
- fludrocortisone (postural hypotension)
- hydrocortisone (surgery and emergencies e.g. anaphylaxis)
- methylprednisolone
- prednisolone (asthma, copd, ibd, severe eczema)
- triamcinolone
What does high mineralcorticoid activity lead to?
fluid retention
Fludrocortisone uses?
Potent mineralcorticoid
- if fluid retention is useful - e.g. in low blood pressure
- e.g. neuropathic postural hypotension (diabetes) or adrenal insuficciency due to septic shock
- anti-inflammatory effect of no clinical relevance
Hydrocortisone use?
Significant mineralcorticoid
- not for long term disease suppression - fluid retention
- useful glucocorticoid on short term basis via IV in surgeries or emergency e.g life threatning asthma or thyrotoxicosis
What is the most potent mineralcorticoid?
Fludrocortisone
What is hydrocortisone not used for?
Long-term disease suppression (fluid retention)
Mineralcorticoid side effects?
Na+ and water retention = hypertension
K+ and Ca2+ loss
- Most marked with fludrocortisone
- Significant with hydrocortisone, corticotrophin, tetracosactide
- Negligible with betamethasone and dexamethasone
What does high glucocorticoid activity equal?
ANTI-INFLAMMATORY
What does high glucocorticoid activity equal?
ANTI-INFLAMMATORY
Most potent glucocorticoid ?
Dexamethasone/betamethasone
Dexamethasone/betamethasone uses?
(HIGH GLUCOCORTICOID ACTIVITY)
- used if fluid retention is a disadvantage e.g. heart failure
- very little mineralcorticoid activity
Prednisolone/prednisone use ?
(Significant glucocorticoid activity)
- prednisolone most common steroid used by mouth
- e.g. acute or severe chronic asthma, COPD, IBD
Another significant glucocorticoid?
Deflazcort
What do high corticosteroid doses cause?
Avascular necrosis of femoral head
Glucocorticoid side effects?
- Endocrine
- Musculoskeletal:
- Gastro-intestinal
- Psychiatric reactions
- Infections (immunosuppression)
- Adrenal suppression
- Opthalmic
- Skin
- Central nervous system
- Growth restriction
- Cushings syndrome (high doses)
Glucocorticoid endocrine side effects?
diabetes (hyperglycaemia)
Glucocorticoid muscoskeletal side effects?
- osteoporosis (>3 months use: prophylaxis with biphosphonate) High corticoidsteroid doses cause avascular necrosis of femoral head)
- muscle wasting, proximal myopathy (caution with statins)
Glucocorticoid GI side effects?
Peptic ulcers, gastro-intestinal, dyspepsia
Counselling: take with or after food
Glucocorticoid psychiatric side effects?
- A serious paranoid state or depression with suicide risk while taking systemic corticoidsteroids or on withdrawal
- Mood and behaviour changes; euphoria, irritable, mood lability, insomnia, nightmares, psychotic reactions, suicidal thoughts and behavioural disturbances
- Counselling: report immediately
Glucocorticoid infections (immunosuppression) side effect?
Increased susceptibility and severitym atypical clinical presentation. Serious infections not detected until advanced stage
- Avoid close contact with chickenpox or shingles, Exposed non-immune patients need passive immunisation with varicella-zoster immunoglobulin (applies to patients currently taking or stopped < 3 months. If chickenpox develops - need urgent specialist treatment)
- Avoid exposure to measles, Seek urgent medical advice if exposed. Prophylaxis with normal immunoglobunlin may be needed
Glucocorticoid adrenal suppression side effect?
- Adrenal suppression approx 1 year after stopping
- Fatigue, anorexia, n+v, hyponatraemia, hypotension, hyperkalaemia and hypoglycaemia
- Avoid abrupt withdrawal if use > 3 weeks (acute adrenal insufficiency. hypotension, death)
- Higher doses in significant intercurrent illness/stress. Patient must mention they are taking steroids or if they have stopped in less than a year during any treatment for illness or injury
- Anaesthesia = dangerous fall in blood pressure, need adrenal replacement with IV hydrocortisone
Glucocorticoid opthalmic side effects?
- Glaucoma, Cataracts
- MHRA advice: corticosteroids: rare risk of central serous chorioretinopathy with local sytemic use. Counselling: report blurred vision and visual disturbances, Consider referral to opthalmologist
Glucocorticoid skin side effects?
- Skin thinning
- Purple-red striae
- Bruising
Glucocorticoid CNS side effects?
- aggravated epilepsy
- schizophrenia
Glucocortioid growth suppression side effect?
In children
MHRA advice for methylprednisoloe injectable medicine containing lactulose?
Do not use in patients with cows milk allergy. Serious reactions including bronchospasm and anaphylaxis reported in patients with cows milk allergy. If symptoms worsen or new allergic symptoms occur, stop and treat
How to manage steroid side effects?
- lowest effective dose for minimum period
- local treatment rather than systemic route
- single dose in the morning: suppressive action on cortisol secretion is least in the morning
- alternate day administration by taking 2 days worth as single dose to further reduce suppression
- intermittently with short courses
When to avoid abrupt withrawal of steroids ?
- long term use > 3 weeks
- > 40mg prednisolone daily or equivalent for more than 1 week
- Repeat doses are taken in the evening
- Recent repeated courses
- Short course within 1 year of stopping long-term steroids
- Have other causes of adrenal suppression
What should be issued to every patient taking long-term corticoidsteroids for more than 3 weeks?
Steroid card
- consider issuing to patients using greater than maximum licensed doses of ICS
Corticosteroids and pregnant/breastfeeding?
- generally safe
- monitor fluid retetntion in pregnant women
What is Adrenal replacement therapy?
Treatment usually involves corticosteroid (steroid) replacement therapy for life. Corticosteroid medicine is used to replace the hormones cortisol and aldosterone that your body no longer produces. It’s usually taken in tablet form 2 or 3 times a day.
Adrenalectomy, addisons disease features and treatment ?
- low cortisol (natural glucocorticoid)
- low aldosterone (natural mineralcorticoid)
- replacement: hydrocortisone + fludrocortisone
Hypopituitarism features and treatment ?
- pituitary gland does not stimulate hormone secretion by target glands
- replacement: hydrocortisone but NOT fludrocortisone; (renin-angiotensin sytem will regulate aldosterone)
- replace other hormones e.g sex. thyroid hormones
What is cushings syndrome charactirised by?
Hypercortisolism (high cortisol)
Cushings syndrome symtpoms?
Skin thinning, easy bruising, reddish-purple stretch marks; striae, fat deposits in the face, moon face, acne, hirsutism and amenorrhoea
Cushings syndrome causes?
- Corticosteroids = reduce dose or withdraw
- Tumour = surgery or cortisol-inhibiting drugs; (metyrapone (competitive) or ketoconazole (potent))
Cushings sydrome treatment?
- ketoconazole: life threatning hepatotoxicity, pt counselling: report signs or liver toxicity: anorexia, abdominal pain, dark urine, jaundice, itching, pale stools, n+v etc
- cortisol-inhibiting drugs; adrenal insufficiency. pt counselling: report fatigue, anorexia, n+v, hypotension. Adrenal suppression causes hyponatraemia, hyperkalaemia and hypoglycaemia
What is diabetes mellitus characterised by?
Hyperglycaemia
Type 1 diabetes ?
“insulin deficiency”
- pancreatic beta islet cells are destroyed causing insufficient insulin
- treatment with insulin
Type 2 diabetes?
“insulin resistance”
- reduced insulin secretion/peripheral resistance to insulin
- treatment with diet, oral antidiabetic drugs or insulin
Diabetes symptoms?
- polyphagia (excessive hunger)
- polydipsia (excessive thirst)
- polyuria (excessive urination)
- weight loss
- fatigue
- blurred vision
- poor wound healing
Diabetes long term macrovascular complications?
- diabetes is a strong risk factor for cardiovascular disease: coronary heart disease, cardiomyopathy, arrhythmias and sudden death, cerebrovascular disease and peripheral artery disease. Cardiovascular disease is the primary cause of death in diabetic patients.
What is given during primary prevention in diabetes?
Statin in type 1 and type 2 diabetes with a Qrisk >10%
*low dose aspirin is not recommended for primary prevention. Ace inhibitors may have a role in preventing CVD
Microvascular complications for diabetes?
- eyes: retinopathy, treat hypertenison; protects visual activity
- kidneys: nephropathy (proteinuria/microalbuminuria)
- sensory painful neuropathy (diabetic foot)
- autonomic neuropathy
- gustatory neuropathy
- neuropathic postural hypotension
How to treat retinopathy?
Treat hypertension, protects visual acuity
How to treat nephropathy?
Treat with ACE inhibitor/ARB
NB: ACE inhibitors potentiates hypoglycaemic effects of hypoglycaemic effects of antidiabetic drug and insulin, especially in renal impairment
How to treat diabetic foot?
- analgesics: strong opioid = oxycodone/morphine; specialist use
- duloxetine, TCAs: amitriptyline, nortriptyline
- anti-epileptics: gabapentin, pregabalin, carbamazepine
How to treat autonomic neuropathy?
- diabetic diarrhoea: codeine or tetracycline
- gastroparesis: erythromycin
- erectile dysfunction: sildenafil
How to treat gustatory neuropathy?
(sweating face, scalp, head and neck)
- treat wih antimuscarinic/antiperspirant
How to treat neuropathic postural hypotension?
Fludrocortisone and increased salt intake
When do insulin requirements increase in pregnancy?
- increase in 2nd and 3rd trimester
What is the aim HbA1c for pre-existing diabetes and pregnancy and what else should be taken to reduce the risk of congenital malformations?
Aim HbA1c level below 48mmol/mol (6.5%)
*5mg folic acid daily (diabetes is a high risk group for neural tube defects)
What is the first choice insulin treatment in pre-existing diabetes in pregnancy?
ISOPHANE INSULINE (humulin) (longer acting): may be appropriate to continue using long-acting analogues: glargine or determir, if good glycemic control before pregnancy
Other insulin treatment choices for pre-existing diabetes in pregnancy for women with difficulty achieveing glycaemic control?
CONTINUOUS SUBCUTANEOUS INFUSION PUMP: for women with difficulty achieving glycaemic control with multiple daily injections without significant disabling hypoglycaemia
What to do if there is an increased risk of hypoglycaemia postnatal period:
reduce insulin immediately after birth; monitor blood glucose to establish dose
Counselling for hypos in pregnancy in pre-existing diabetes?
Hypoglycaemic risks in all pregnant women treated with insulin (especially in first trimester)
- carry a fast acting form of glucose e.g. dextrose/glucose drink
- for type 1 - prescribe glucagon if needed
Pre-existing type 2 diabetes and pregnancy?
- stop all oral antidiabetic drugs except metformin, substitute with insulin
- metformin alone or with insulin
Breastfeeding and type 2 diabetes?
Continue metformin or resume glibenclamide post birth
For gestational diabetes when should treatment be stopped?
After birth
What is first and second line for fasting blood glucose < 7mmol/L at diagnosis of gestational diabetes ?
FIRST LINE: dietary and exercise measures
SECOND LINE: metformin if blood glucose target not met in 1-2 weeks
Alternative: Insulin (also added to metformin if alone not effective)
What is first line if fasting blood glucose >7mmol/L at diagnosis for gestational diabetes ?
FIRST LINE: insulin with or without metformin + dietary and exercise measures
What is first line for fasting blood glucose 6-6.9mmol/L with hydramnios (too much amniotic fluid) or macrosomia (newborn larger than average)?
FIRST LINE: insulin with or without metformin
What can be used in gestational diabetes for women intolerant of metformin and do not want insulin?
Glibenclamide (from 11 weeks gestation; after organogenesis)
When is DKA more common?
more common in type 1
DKA symptoms?
- severe hyperglycaemia
- high blood ketones
- ketonuria (ketones in urine)
- pear drop breath
- dehydration/excessive thirst
- polyuria
- nausea, vomiting
- anorexia
- abdominal pain
- difficulty breathing
- electrolyte imbalance
- mental confusion
- drowsiness
- diabetic coma
- convulsions
DKA treatment?
IV INFUSION
- soluble insulin
- fluids (saline)
- potassium (do not give if anuria - no urine)
- Continue established long-acting insulin e.g. determir, glargine
- Add glucose to infusion when below 14mmol/L
- continue until patient able to eat and drink and blood pH above 7.3
- give SC fast acting insulin and meal, stop infusion one hour later
Diabetes and driving?
- Notify the DVLA when on insulin or any medication for group 2 drivers (do not need to notify in diet controlled diabetes)
- group 1 = cars and motorbikes
- group 2 = lorry, bus, coach
Hypoglycaemia:
- 2 episodes of sevre hypoglycaemia in past 12 months (one episode if group 2)
- impaired awareness
- disabling hypoglycaemia while driving
What monitoring should be done whilst driving to avoid hypoglycaemia?
- check blood glucose no more than 2 hours before driving and every 2 hours for long journey
- for those on insulin
- group 2 drivers on sulphonylurea, glinides.
- record readings at least twice a day even when not driving!
- drivers on insulin must always carry fast-acting sugar supply e.g. glucose tablet and avoid driving if meal is delayed
Blood glucose levels and driving?
5mmol/L = take a carbohydrate before driving
< 4mmol/L = do not drive
What to do if hypoglycaemia occurs whilst driving?
- stop vehicle in safe place and switch engine off
- eat or drink a fast acting sugar and then long acting carbohydrate e.g. sandwich to maintain levels
- wait 45 mins after blood glucose levels return to normal, before continuing journey
What is insulin?
Polypeptide hormone responsible for the metabolism of carbohydrates, fat and protein
3 types of insulin?
- Human insulin (soluble insulin)
- Human insulin analogues (rapid and long-acting)
- Beef/pork insulin (short acting soluble animal)
Short acting soluble insulin?
- Human soluble
- Beef/pork
- Via SC/IM/IV diabetic emergencies and surgery
- Animal insulin may not be acceptable in moral/religious beief
- BOLUS INSULIN (short period of time)
- Take 15-30 mins before a meal
- Consume meal within 30 mins to avoid hypoglycaemia
Rapid- acting insulin analogue?
- LISPRO (humalog)
- ASPART (novorapid)
- GLULISINE (apridra)
- lower risk of hypo before lunch + late dinner, than soluble
- alternative to soluble in emergency
- BOLUS INSULIN
- take immediately before or after a meal
Intermediate acting insulin?
ISOPHANE (NPH) - Novolin N, Humulin N, Insulatard
- never give IV = thrombosis
- protamine causes allergic reactions
- BASAL INSULIN (set amounts of insulin at intervals)
- take BD in conjunction with soluble insulin