Hi, Microcid-SR is a brand name for a medication called Aceclofenac, which belongs to a class of drugs called nonsteroidal anti-inflammatory drugs (NSAIDs). It is commonly used to reduce pain and inflammation associated with various conditions such as rheumatoid arthritis, osteoarthritis, ankylosing spondylitis, and gouty arthritis. In your case, since you have been experiencing joint pains in your right knee, right elbow, and left thumb, your doctor may have prescribed Microcid-SR to reduce the pain and inflammation associated with these conditions. The medication works by inhibiting the production of certain chemicals in the body that cause pain and inflammation. It is important to note that while Microcid-SR can be effective in reducing pain and inflammation, it may also have side effects. Common side effects of Aceclofenac include stomach upset, nausea, vomiting, dizziness, and headache. In rare cases, it can also cause serious side effects such as bleeding in the stomach or intestines. Therefore, it is important to take the medication only as prescribed by your doctor and to report any side effects immediately. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Priyanka, General & Family Physician