Thanks for writing in to Healthcare Magic!
It can cause gastric intolerance and diarrhea
but as such does not cause weakness.
It is possible through a severe diarrhea in that case treatment of diarrhea is important and will solve the problem.
The other cause of weakness can be a diuretic
if started recently.
Still if you want to switch, consult your physician with the option if Acenocoumarol
If you have any further query please let me know I would try to answer it for you.
Wish you a great health!