Overview
- The NHS reiterates six common side effects of metformin: feeling sick, being sick, diarrhoea, stomach ache, loss of appetite and a metallic taste in the mouth.
- Patients are told serious reactions are rare, occurring in fewer than 1 in 10,000 people, and to contact a GP or dial 111 for severe tiredness, fast or shallow breathing, feeling cold with a slow heartbeat, or yellowing of the eyes or skin.
- People should call 999 immediately for suspected anaphylaxis, including sudden swelling of the lips, mouth or throat, severe breathing difficulty, a tight throat, sudden confusion or fainting, or skin or lips turning blue, grey or pale.
- The guidance notes a risk of vitamin B12 deficiency with use and warns that low blood sugar can occur when metformin is taken with other diabetes medicines such as insulin or gliclazide.
- More than 26 million metformin prescriptions were dispensed in England last year, with over 5.8 million people in the UK now living with diabetes, according to Diabetes UK.