Endocrine Flashcards
how does insulin work?
stimulates glucose uptake from the circulation into tissues, including skeletal muscle and fat, and increases use of glucose as an energy source.
stimulates glycogen, lipid and protein synthesis and inhibits gluconeogenesis and ketogenesis.
For the treatment of hyperkalaemia, insulin drives K+ into cells, reducing serum K+ concentrations.
what are the indications to take insulin?
diabetes, hyperkalaemia
what are the contraindications to taking insulin?
renal impairment
what are the side effects of insulin?
Hypoglycaemia, lipohypertrophy in site of SC injection
what are the interactions with insulin?
other hypoglycaemic agents increases the risk of hypoglycaemia
systemic corticosteroids increases insulin requirements.
what class of drug is gliclazide?
sulphonylurea
how does gliclazide work?
lower blood glucose by stimulating pancreatic insulin secretion.
what are the indications to take gliclazide?
type 2 diabetes (only used if metformin not tolerated)
what are the contraindications to taking gliclazide?
hepatic and renal impairment
what are the side effects of gliclazide?
hypoglycaemia, GI disturbances (nausea, vomiting, diarrhoea, constipation), hyponatraemia, rarely causes liver disturbances
what are the interactions with gliclazide?
other antidiabetic drugs including metformin, thiazolidinediones (e.g. pioglitazone) and insulin.
The efficacy of sulphonylureas is reduced by drugs that elevate blood glucose, e.g. prednisolone, thiazide and loop diuretics.
how does metformin work?
lowers blood glucose by increasing the response (sensitivity) to insulin
suppresses hepatic glucose production, increases glucose uptake and utilisation and suppresses intestinal absorption. Also reduces weight gain, preventing worsening insulin resistance
what are the indications to take metformin?
Type 2 DM (first choice for blood glucose control)
what are the contraindications to taking metformin?
hepatic and renal impairment
Ketoacidosis, general anaesthesia
what are the side effects of metformin?
Anorexia, nausea, vomiting, diarrhoea, abdo pain, taste disturbance and rarely lactic acidosis
what are the interactions with metformin?
any drug that interferes with hepatic or renal function
Prednisolone, thiazide and loop diuretics elevate blood glucose, hence oppose the actions and reduce efficacy of metformin.
how does thyroxine work?
replaces T4 in the body which regulate metabolism and growth
what are the indications to take thyroxine?
Primary hypothyroidism.
Hypothyroidism secondary to hypopituitarism.
what are the contraindications to taking thyroxine?
coronary artery disease
hypopituitarism (can induce addisonian crisis)
thyrotoxicosis
what are the side effects of thyroxine?
only get in excessive dose - gastrointestinal (e.g. diarrhoea, vomiting, weight loss), cardiac (e.g. palpitations, arrhythmias, angina) and neurological (e.g. tremor, restlessness, insomnia) manifestations.
(same as hyperthyroidism)
what are the interactions with thyroxine?
gastrointestinal absorption of levothyroxine is reduced by antacids, calcium or iron salts
increased dose may be necessary in patients taking cytochrome P450 inducers (phenytoin, carbamazepine)
increase insulin or oral hypoglycaemic requirements in diabetes mellitus and enhance the effects of warfarin.
what class of drug is carbimazole?
Anti-thyroid drugs
how does carbimazole work?
Decreases uptake and concentration of inorganic iodine by thyroid also reducing the formation of di-iodotyrosine and thyroxine (so reduces production of T3 and T4)
what are the indications to take carbimazole?
hyperthyroidism
what are the contraindications to taking carbimazole?
Severe blood disorders
what are the side effects of carbimazole?
Nausea, mild GI disturbance, taste disturbance, headache, fever, malaise, rash, pruritus, arthralgia
what class of drug are alendronic acid, disodium pamidronate and zoledronic acid?
Bisphosphonates
how do bisphosphonates work?
reduce bone turnover by inhibiting the action of osteoclasts, the cells responsible for bone resorption
net effect is reduction in bone loss and improvement in bone mass.
what are the indications to take bisphosphonates?
osteoporotic fragility fractures
Paget’s disease
what are the contraindications to taking bisphosphonates?
renal impairment
hypocalcaemia
upper GI disorders
smokers/ dental disease (risk of jaw osteonecrosis)
what are the side effects of bisphosphonates?
oesophagitis (when taken orally) and hypophosphataemia
osteonecrosis of the jaw
what are the interactions with bisphosphonates?
absorption is reduced if taken with calcium salts (including milk), as well as antacids and iron salts
how do calcium and vitamin D supplements work?
Calcium – essential for normal muscle/bone/nerve/clotting function
Vitamin D – controls calcium homeostasis along with parathyroid hormone)
Reduces rate on bone loss
what are the indications to take calcium/Vit D?
Osteoporosis, chronic kidney disease, severe hyperkalaemia, hypocalcaemia, vitamin D deficiency
what are the contraindications to taking calcium/Vit D?
hypercalaemia
what are the side effects of calcium/Vit D?
Dyspepsia, constipation, risk of cardiovascular collapse when given too quickly in treatment of hyperkalaemia
what are the interactions with calcium/ Vit D?
Iron, bisphonsphonates, tetracyclines, levothyroxine (reduces absorption); sodium bicarbonate when given IV (risk of precipitation)
what class of drug is fludrocortisone?
mineralcorticoid
how do mineralcorticoids work?
works by causing the kidneys to retain sodium and acting as a replacement for cortisone when the body does not produce enough.
what are the indications to take mineralcorticoids?
adrenocortical insufficiency in Addison disease
treating salt-losing adrenogenital syndrome.
what are the contraindications to taking mineralcorticoids?
Systemic infection, avoid live virus vaccines when receiving immunosuppressive doses
what are the interactions with mineralcorticoids?
Anabolic steroids increase the risk of fludrocortisone’s side effects
Barbiturates, carbamazepine, estrogens, phenytoin, rifampin decrease fludrocortisone’s effectiveness
live vaccines, or smallpox vaccine because the effectiveness of these medicines may be decreased
Anticoagulants because their effectiveness may be decreased or the risk of their side effects may be increased
what are the side effects of mineralcorticoids?
Difficulty sleeping; dizziness or lightheadedness; headache; increased appetite; increased sweating; indigestion; nervousness; increase susceptibility to infection
