Can I set Nimesil if it does not help and there are side effects from the digestive system?

Good morning For several weeks my shoulder hurts and the pain radiates to the elbow. The doctor prescribed me Nimesil 2 * a day for 5 days and then until the end of the package. I am in the second week of treatment, the shoulder still hurts, but there were problems from the digestive system. Should I take to the end or put aside. I mention that I can not get to the doctor. Best regards