Endocrine Flashcards
Types of insulin T2DM
- sulphonylureas
- biguanides
example of sulphonylureas
Gliclazide
how does gliclazide work
decreases blood glucose by increasing insulin secretion from the pancreas
- does this by blocking ATP dependent K+ channel, depolarisation, opening of Ca2+ channel, increasing insulin secretion
when is gliclazide used
Type 2 diabetes (not T1 as pancreatic function must be working still)
- used where metformin is contraindicated or in addition to metformin
contraindications of gliclazide
cautious in renal and hepatic impairment
side effects of gliclazide
- hypoglycaemia
- weight gain (this can worsen diabetes)
- GI upset
possible interactions with gliclazide
other anti-diabetic drugs increases risk of hypo
how does weight gain affect diabetes
increases insulin resistance
example of biguanides
metformin
how does metformin work
decreases blood glucose by increase response to glucose and glucose uptake in cells
- does this by decreasing glucose intestinal absorption
- since it does not increase insulin secretion, cannot cause hypos
- also, increases weight loss and prevents weight gain and resistance to insulin, improving diabetes prognosis
when is metformin used
first line in Type 2 diabetes
contraindications of metformin
AKI, severe tissue hypoxia, excess alcohol
side effects of metformin
- GI disturbance
- weight loss
- rare but severe: lactic acidosis
possible interactions of metformin
- should be withheld 48hrs before injection of contrast such as in CT, coronary angiography
- prednisolone / loop / thiazide diuretics reduce efficacy as oppose effects as increase glucose
types of insulin T1DM
- rapid acting
- short acting
- immediate acting
- long acting
- biphasic
rapid acting insulin
immediate and short duration
Novorapid
short acting insulin
early onset and short duration
Actrapid
immediate acting insulin
immediate acting and duration
Humulin 1
long acting insulin
flat acting and regular duration
Levemir, Lantus
biphasic insulin
mix between rapid and immediate acting insulin
Novomix 30
how does insulin work
- similarly to endogenous insulin by increase glucose uptake in tissues, decreasing blood glucose
- simulates gluconeogenesis, vetogenesis and protein synthesis
when is insulin used
- T1DM (+T2 if not controlled by oral meds)
- IV in diabetic emergencies like DKA or diabetic hyperosmolar syndrome
- hyperkalaemia (alongside glucose to prevent hypos)
contraindications of insulin
renal impairment
side effects of insulin
- hypoglycaemia
- lipohypertrophy due to repeated injections in the same place (fat overgrowth)
how to administer insulin
sub cut injections before food
thyroid drugs
levothyroxine / thyroxine
how does thyroxine work
replacement of thyroid hormones: T4 (thyroxine) which is converted into triiodothyronine (T3) to regulate metabolism and growth
when is levothyroxine used
- hypothyroidism
- hypothyroidism secondary to hypopituitarism
contraindications for levothyroxine
cautious in coronary artery disease
side effects of levothyroxine
symptoms of hyperthyroidism
possible interactions of levothyroxine
increase dose required if also taking cytochrome P450 inhibitors
administration of levothyroxine
50-100 micrograms for life (decrease to 25-50 in elderly)
example of anti-thyroid drugs
carbimazole
how does carbimazole work
pro-drug which is converted to methimazole
- methimazole prevents thyroid peroxidase, reducing T3 and T4 production
when is carbimazole used
hyperthyroidism
contraindications of carbimazole
- early months of pregnancy and breastfeeding
- severe liver disease
- blood disorders
side effects of carbimazole
- prurutis / rash (can be treated with anti-histamine)
- bone marrow suppression resulting in neutropenia
- stop if sore throat or fever
possible interactions of carbimazole
warfarin, theophylline, erythromycin, steroids
examples of bisphosphates
alendronic acid (PO), zoledronic acid (IV)
how do bisphosphates work
- absorbed in bone and promote apoptosis for osteoclasts, decreasing bone loss and increasing bone ,ass
when are bisphosphates used?
- osteoporosis (alendronic acid)
- bone metastases / malignancies (zoledronic acid)
- hypercalaemia of malignancy (zoledronic acid)
- Paget’s disease (alendronic acid)
contraindications of bisphosphates
- hypocalcaemia
- renal impairment
- upper GI disorders
side effects of bisphosphates
- oesophagitis
- hypophosphataemia
- jaw osteonecrosis
possible interactions of bisphosphates
absorption decreased if taken with calcium salts
importance of calcium and vitamin D
- Calcium is essential for muscles, nerves, bones and clotting
- Calcium homeostasis is controlled by PTH and vitamin D which increases calcium and calcitonin and bone mineralisation which decreases calcium levels
when is calcium and vitamin D used
- osteoporosis
- CKD
- hyperkalaemia
- hypocalcaemia
- lit D deficiency (rickets in children and osteomalacia in adults)
calcium and vitamin D in osteoporosis
decreases rate of bone loss
calcium and vitamin D in CKD
treats and prevents secondary hyperparathyroidism and renal osteodystrophy (in CKD, decreased vitamin D absorption and decreased phosphate excretion leading to hyperparathyroidism and hypocalcaemia)
calcium and vitamin D in hyperkalaemia
calcium gluconate given to protect the heart
contraindications of calcium and vitamin D
hypercalcaemia
side effects of calcium and vitamin D
dyspepsia, constipation, CV collapse if IV given too fast in hyperkalaemia
possible interactions of calcium and vitamin D
oral Ca decreases absorption of drugs such as bisphosphates, tetracyclines and levothyroxine
examples of mineralocorticoids
aldosterone, fludrocortisone
when are mineralocorticoids used?
adrenocorticol insufficiency (acts as replacement)
when are mineralocorticoids contraindicated
systemic infection, live viral vaccines
side effects of mineralocorticoid
immunosuppression, easy bruising, muscle weakness, mood changes
possible interactions of mineralocorticoids
- increase risk of PUD and bleeding with NSAIDs
- increase risk of hypokalaemia with B2 agonists, theophylline, thiazide and loop diuretics
- decreases immune response to vaccines
how do mineralocorticoids affect electrolytes
- increase sodium and water retention and potassium excretion
