Metformin

Question 1

What class of drug is Metformin?

Answer 1

Biguanide

Question 2

What are the common indications of Metformin?

Answer 2

• Type 2 Diabetes Mellitus

Question 3

What is the mechanism of action of Metformin?

Answer 3

• Reduced hepatic glucose production by inhibiting gluconeogenesis
• Suppresses appetite so limits weight gain (be careful in those with already low weights)

Some gluconeogenic activity remains so there’s less risk of hypoglycaemia

Can be given as a modified release drug

Question 4

What are the common adverse drug reactions of Metformin?

Answer 4

GI upset - nausea, vomiting, diarrhoea

As a modified release drug, these side effects are reduced

Question 5

What are the common drug-drug interactions of Metformin?

Answer 5

• Drugs that impair renal function - ACEi, diuretics, NSAIDs (as metformin is removed via the kidneys)
• Drugs that increase glucose so would reduce the action of metformin - loop and thiazide like diuretics