Metformin Flashcards
What is the mechanism of action of metformin?
Lowers blood glucose by increasing the sensitivity to insulin, whilst suppressing hepatic glucose production, increasing glucose uptake and increasing muscular utilisation of glucose. I also suppresses intestinal glucose absorption
Why does metformin not cause hypoglycaemia?
It doesn’t stimulate insulin release
Does metformin promote weight loss?
Yes - can prevent worsening insulin resistance
What are side effects of metformin?
- GI upset - nausea, vomiting, taste deisturbance, anorexia, diarrhoea
- Lactic acidosis
-
Weight loss
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What are indications for metformin use?
- T2DM
- PCOS
What are contraindications to metformin use?
- GA
- IV contrast x-rays
- Acute metabolic acidosis
- eGFR < 30
- Low BMI
When should metformin be stopped for surgery?
On the day of the surgery
When should you be cautious prescribing metformin?
Renal impairment - eGFR < 45 ml/min/1.73m2
How can alcohol interact with metformin?
CAn cause lactic acidosis
When should metformin be witheld?
- AKI
- Severe tissue hypoxia
- Sepsis
- Acute alcohol intoxication
IF someone taking metformin had to go for an IV contrast media scan, how woulf this affect his prescription of metformin?
Withold before and 48 hours after injection
What drugs can interact with metformin?
Those which affect renal function
- NSAIDs
- ACEi
- Diuretics
Those which increase blood glucose
- Steroids
- Loop/thiazide fdiuretics
What dose of meformin would you start someone on?
500mg once per day
When would you advise individuals to to take metformin?
With or after meals
What monitoring would you consider doing with someone on metformin?
- HbA1c
- Renal function before and annually after starting treatment
