Endocrine System Flashcards
What is the mechanism of action of metformin?
Decreases glucoseneogenesis and increases peripheral utilisation of glucose
(Acts only in the presence of insulin = only effective when there is some functioning of pancreases cells)
THEREFORE DOESNT CAUSE HYPOGLYCAEMIA as doesn’t stimulate insulin secretion
Dose of metformin
Type II; MAX 2g per day
MR versions to prevent stomach issues
Polycystic ovary syndrome
First choice for all patients
Metformin contraindication
Acute metabolic acidosis including lactic acidosis and ketoacidosis
EGFR <30 mL/min/1.73 m2 or <45 mL/min.1.73 m2 for MR versions
Risk factors for lactic acidosis
HF or recent MI
Alcohol intoxication
Renal impairment
Respiratory failure
Dehydration
Fasting
Liver impairment
Ketosis
Adverse effects of Metformin
GI disorders; abdominal pain, diarrhoea, decreased appetite, altered taste
Consider switch to MR Or slow dose increase
Lactic acidosis risk
Decrease B12 absorption
Weight loss
Taste disturbances
Symptoms of lactic acidosis
Dyspnoea
Muscle cramps
Abdominal pain
Hypothermia
Asthenia
Mechanism of action of sulphonylurea?
Stimulates the release of insulin from pancreatic beta cells therefore decreasing the concentration of glucose
RISK OF HYPOGLYCAEMIA
Adverse effects of Sulphonylurea?
Weight gain
GI disturbances
Hypoglycaemia (greater risk with long acting)
Hepatic impairment (jaundice, hepatitis, hepatic failure)
Allergic skin reaction in first 6-8 wks
Long acting Sulphonylurea
Glibenclamide
Glimepiride
Short acting sulphonylurea
Gliclazide
Tolbutamide
Glipizide
Gliclazide advantage
Metabolised by liver therefore can be used in renal impairment patients
Short acting = lower risk of hypos
Caution and CI in sulphonylureas
Elderly patients - best to give short acting
Patients with G6PD deficiency
Acute porphyria
Ketoacidosis
Avoid/reduce dose in renal impairment
Given if metformin is CI as first line and pt is not overweight
How do you take sulphonylureas?
With or immediately after breaskfast
sulphonylurea interactions?
Warfarin and ACEi increase the risk of hypos
NSAIDs decrease renal excretion
Alpha glucosidase inhibitors mechanism of action and example?
Acarbose
Inhibits alpha glucosidase. Delays digestion and absorption stage of sucrose
Poorer anti diabetic medication
What do you give is pt is in acarbose and is having a hypo?
Give glucose
Interferes with sucrose absorption therefore give glucose
Side effects of alpha glucosidase inhibitor?
Flatulence
Diarrhoea
Pioglitazone mechanism of action?
Is a thiazolidinedione
Reduces insulin resistance leading to reduction in blood glucose concentration
(Enhances action as it increases insulin sensitivity in tissues = reduces blood glucose)
Pioglitazone side effects?
Bone fracture
Weight gain
Visual impairmentt
Increase infection risk
Nausea
Thirst
Urinary disorders
MHRA alerts for Pioglitazone
CV safety; HF (symptoms; fluid retention, weight gain)
Risk of bladder cancer (symptoms; haematuria, dysuria, urinary urgency)
Patient and carer advise for pioglitazone
Report signs of liver toxicity
Unexplained N&V
Abdominal pain
Fatigue
Anorexia
Dark urine
Contraindications for pioglitazone?
bladder cancer history
Liver impairment
HF
Haematuria
Pioglitazone interactions
Clopidogrel can increase pioglitazone exposure = severe interaction
Pioglitazone monitoring
Signs and symptoms of fluid retention (weight gain or oedema)
Liver functions (hepatotoxic / toxicity)