Deolrest injection is a pain-relieving medication used to treat moderate to severe pain in conditions like osteoarthritis and rheumatoid arthritis. It relieves joint and muscle swelling and should be taken with food to avoid upset stomach. Common side effects include mild vomiting, stomach pain, nausea, headache, and dizziness. Patients with a history of stomach ulcers, heart diseases, high blood pressure, liver or kidney disease, and pregnant or breastfeeding mothers should consult their doctors before using this medication.