Endocrine Drugs Flashcards
Mechanism of action of insulin
Lowers plasma glucose concentration by:
- stimulating glucose transport into fat and muscle cells
- stimulate glycogen synthesis
- inhibiting gluconeogenesis and lipolysis
Indications for insulin
- diabetes type 1 and 2
- ketoacidosis
- hyperglycaemic hyper osmotic non-ketotic coma
- emergency treatment hyperkalaemia
Side effects of insulin
- hypoglycaemia
- weight gain
- fat hyper trophy at injection sites
Possible interactions of insulin ?
- B-blockers: masks the warning signs of hypoglycaemia by interfering with sympathetic nervous system
What type of drug is insulin ?
Peptide Hormone
What drug class is gliclazide ?
Sulphonylurea
Mechanism of action if gliclazide ?
- stimulates insulin production by binding Sulphonylurea receptors and blocking ATP-dependent potassium channels in pancreatic B cells,
- inhibiting potassium efflux
- causes internal depolarisation which stimulates insulin release
Indications for gliclazide ?
- type 2 diabetes (when diet and exercise have not worked, and when Metformin is contraindicated/not tolerated)
- only if beta cells are still functional to release endogenous insulin, effect becomes less effective as beta cells depleted*
Contraindications for gliclazide ?
- ketoacidosis
- pregnancy/breastfeeding
Side effects of gliclazide ?
- hypoglycaemia
- weight gain
- rarely: headache, rash, GI disturbance, bone marrow suppression
Possible interactions of gliclazide ?
Fluconazole: increased plasma concentrations of gliclazide
Route of elimination of gliclazide ?
Hepatic
What drug class is Metformin ?
Biguanides
Mechanism of action of Metformin ?
Lowers blood glucose by:
- reduces gluconeogenesis
- promotes sensitivity of tissues to insulin
- delays glucose absorption and stimulates glycolysis
Indications for Metformin ?
Type 2 diabetes (when diet and exercise have not worked)
Side effects of Metformin ?
- flatulence
- anorexia
- abdo bloating
- nausea/vomiting/diarrhoea
- lactic acidosis
Contraindications if Metformin ?
- pregnancy/breastfeeding
- surgery, infections, trauma
- hepatic or renal impairment
- alcohol ingestion
- DKA
Possible interactions of Metformin
- alcohol: increased risk of lactic acidosis
- corticosteroids: antagonise hypoglycaemia
Elimination of Metformin
Kidneys
What drug class is thyroxine ?.
Thyroid hormone replacement
How does thyroxine work ?
Mimics endogenous thyroxine (T4) and so has effects:
- metabolic (energy, temp, appetite, weight)
- CV (HR, rhythm, BP,)
- skin/hair (thickness, texture)
- MSK (reflexes, bone growth)
- reproductive (ovulation/spermatogenesis)
- increased GI motility
- erythropoiesis
Side effects of thyroxine ?
- thyrotoxicosis -> palpitations, diarrhoea, tremors, anxiety
- result of therapeutic overdosage *
Indications for thyroxine ?
Hypothyroidism
Contraindications of thyroxine ?
- MI (acute recovery phase)
- thyrotoxicosis
- uncorrected adrenal insufficiency
- transient hypothyroidism during recovery phase of subacute thyroiditis
Route of elimination of thyroxine
Liver
Interactions of levothyroxine
- antacids: reduce absorption
- increase met of thyroxine: carbamazepine, phenytoin, rifampicin,
- warfarin: effects of warfarin increased (anticoag)
What drug class is carbimazole?
Anti thyroid
How does carbimazole work ?
- Inhibits thyroid peroxidase, which is necessary for thyroid hormone synthesis
- decreases the production thyroid hormones T3 and T4
Indications for carbimazole
- thyrotoxicosis
Side effects of carbimazole
GI Disturbance, headache, skin rash, pruritis, joint pain
What drug class is alendronate ?
Bisphosphonates
Mechanisms of action of alendronate ?
Poorly understood mechanism: inhibits osteoclasts, preventing the breakdown of bone tissue
Indications for alendronate ?
- post-menopausal osteoporosis
- corticosteroid associates osteoporosis
- Paget’s disease of the bone
- osteoporosis in men to decrease incidence of fractures
Contraindications of alendronate ?l
- renal impairment
- hypocalcaemia
- oesophageal stricture/achalasia
- inability to sit or stand upright for at least 30 mins
Main route of elimination of alendronate ?
Kidneys
Side effects of alendronate ?
- oesophageal irritation/ulceration
- MSK pain
- abdo pain/nausea/vomiting/diarrhoea
- osteoporosis of the jaw
Possible interactions of alendronate ?
- antacids decrease absorption
What drug class is calcium?
Mineral / supplement
Indications for calcium ?
- supplementation for prevention of osteoporosis
- treatment of acid reflux (calcium carbonate only)
Contraindications of calcium ?.
- hypercalciuria
- hypercalcaemia
- renal calculi
What is the main route of elimination of calcium ?
Faeces(80%) urine (20%)
Side effects of calcium ?
- nausea/flatulence/constipation
- arrhythmias
What drug class is vitamin D ?
Vitamin/supplement
Indications for vitamin D ?
Vit D deficiency due to:
- lack of sunlight
- insufficient diet
- osteoporosis
Contraindications of vitamin D ?
- hypercalcaemia
- metastatic calcification
Side effects of giving vitamin D ?
Hypercalcaemia symptoms: weakness, renal dysfunction, osteoporosis, anaemia etc
Possible interactions of vitamin D ?
Carbmazepine/phenytoin: increased vit d requirements
Diuretics: increased risk of hypercalcaemia
