Diabetes Medication Flashcards
What is the mechanism of metformin?
Inhibits the mitochondrial respiratory chain to cause a decrease in ATP which decreases hepatic glucose production to lower glucose levels
Increases gut glucose utilisation and metabolism
Where does metformin act?
Hydrophilic so requires active transport by organic cation transporters to be taken into the intestines, liver and kidney
Is metformin insulin dependent or independent?
Insulin independent
What are the clinical benefits of metformin?
Lowers glucose levels
Weight neutral or negative
Cheap
What is the usual dose of metformin?
500mg bd
Max dose 1g bd
What are the side effects of metformin?
GI intolerance (diarrhoea, bloating, abode pain, dyspepsia, metallic taste in mouth) Metformin associated lactic acidosis
What should be done if a patient on metformin has GI side effects?
Reduce to 500mg od and increase slowly
Or use a modified release formulation
What should be done if a patient on metformin develops metformin associated lactic acidosis?
Max dose 1g daily if eGFR <45
Metformin contraindicated if eGFR <30
Does metformin have an effect on CVD?
Large sustained benefit on CV mortality
When is metformin prescribed?
First line for all diabetic patients
What are examples of sulphonylureas?
Gliclazide (most common)
Glipizide
What is the mechanism of action of sulphonylureas?
Bind to KATP channels of pancreatic beta cells, causing channels to close
This causes depolarisation, calcium channels open and insulin secretion increases
Is the mechanism of sulphonylureas glucose independent or dependent?
Independent - can cause insulin secretion even when glucose is not increased
What type of drug are sulphonylureas?
Insulin secretagogues
What are the clinical benefits of sulphonylureas?
Potent glucose lowering
Cheap
What are the side effects of sulphonylureas?
Increased risk of hypoglycaemia
Weight gain
Do sulphonylureas have an effect on CVD?
May increase risk but unsure, doesn’t decrease risk
Which patients are most at risk of hypoglycaemia on sulphonylureas?
Elderly
Patients who have had diabetes for a long time
High creatine
Lower HbA1c (esp <50mmol/mol)
For which occupations would hypoglycaemia be a risk?
Driving
Working up ladders
When are sulphonylureas prescribed?
2nd line after metformin, especially if cost is a major consideration