Chlorzoxazone+Diclofenac+Paracetamol is safe for most of the patients. However, in some patients it may cause common side effects like nausea, vomiting, heartburn, stomach pain, diarrhea, loss of appetite, dryness in the mouth, weakness, sleepiness and other uncommon or rare side effects. Inform your doctor as soon as possible if you experience any persistent problem due to the medication.