Hi in some instances it can. I would suggest contacting your nurse. Do not let this drags on to long. It is miserable. Have been there and got the tee shirt
If the SR version has the same problems as the standard version you need to ask the DN to stop it. Metformin isn't a miracle cure and the right low-carb diet has far more effect and there are one of tow other drugs which may help.
Although it seems to be the first line of treatment for many, Metformin is not essential if you can manage your BG without it. I could not cope with it and stopped taking the tablets. It meant that I could be more active where before I was unable to leave the house, sometimes I was unable to go downstairs at all.
What dose did you start on? Metformin should be started on the lowest possible dose and increased gradually over weeks to help avoid digestive problems. Taking the pill with a meal also helps. I am currently taking 2g Glucophage SR. Eating <30g carbs daily was lowering my bg but not enough. The Metformin has taken me all the way down to normal readings.