Hi, Mucrocid SR contains indomethacin that is used in the treatment of various painful conditions such as rheumatoid arthritis, gout, ankylosing spondylitis and fever. But like other medications this medication has some side effects of its own. This medication may cause back pain as a side effect. Other side effects of this medication are nausea, vomiting, loss of appetite, unexplained weight gain, painful or difficult urination, blurring of vision, lack of energy, unusual bleeding or bruising, diarrhea or constipation, abdominal pain, GIT upset and many more. These side effects are mild and usually go away over time. But any of these side effects persist for long or bother you then you should consult your doctor first for medical help. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Zubayer Alam, General And Family Physician,