Pharmacology: Oral hypoglycaemic agents Flashcards
What are the 2 broad ways in which type 2 diabetes medications work?
They either stimulate beta cells to produce more insulin or increase sensitivity to insulin
How does Metformin work?
- decreases insulin resistance
- reduces hepatic gluconeogenesis
- limits weight gain
All type 2 diabetics should be offered metformin unless there are contraindications, what are these contraindications?
- renal failure
- GFR less than 30ml/min
- cardiac failure
- liver failure
- respiratory failure
What are the common side effects of Metformin?
- GI side effects such as nausea, diarrhoea, indigestions
- Can interfere with Vit B12 absorption at the ileum but Vit B12 deficiency is rare
How does sulphonylureas work?
What are the side effects?
- stimulate beta cells to release insulin
Side affects include weight gain and hypoglycaemia
How does acarbose work?
What are the side effects?
It is an alpha glucosidase inhibitor so inhibits breakdown of carbs into glucose. Rarely used.
Side effects are predictable - flatulence, loose stools/diarrhoea
How do glitazones work?
- increase insulin sensitivity in muscle and adipose
- decrease hepatic glucose output
What are the side effects of glitazones?
- weight gain
- fluid retention so concerns about heart failure
- exacerbates osteoporosis so shouldnt be used on post-menopausal women
How do glucagon-like-peptide 1 therapies work?
- increase insulin secretion from beta cells
- decrease production of glucagon from alpha cells
- slow bowel motility so food absorbed more slowly
- increases satiety so patients eat less
What are the 2 classes of glucagon-like-peptide 1 therapies?
DPP4 inhibitors: a tablet that breaks down DPP4 which is the enzyme that usually degrades native GLP1
GLP1 agonists: injectable and mimics the action of GLP1
What are the side effects of injectable GLP1 agonists?
- GI symptoms such as nausea and diarrhoea
- Gastro oesophageal reflux
- Occasionally painful to inject
How do the kidneys usually handle glucose?
In the proximal tubule 90% of glucose is reabsorbed by SGLT2
The remaining 10% is reabsorbed by SGLT1 in the Loop of Henle
How does Dapagliflozin (a SGLT blocker) work?
What are the side effects?
Blocks the sodium-glucose-transporter in the proximal tubule to prevent reabsorption of glucose and therefore glucose is excreted in the urine.
Side effects: causes osmotic diuresis, lower UTI, thrush
What is the role of insulin?
- stimulates uptake of glucose into liver, muscle and adipose
- inhibits gluconeogenesis in the liver
- inhibits glycogenolysis
- promotes fat uptake
What are the different types of insulin available?
6 main categories: 1. Ultrafast acting 2. Rapid acting 3. Short acting 4. Intermediate acting 5. Long acting 6. Very long acting (the only differences are the rate the insulin is absorbed)
