Hello, I read your message and understood your medical issue. I see that your father has arthritis and sulfasalazine is a drug used to treat joint pain, swelling, and stiffness in rheumatoid arthritis. In my recordings, Erdal is referred to Sulfasalazine drug. Long use of this drug may turn the pH of the gastric fluid more acidic due to dyspepsia which worsens the ulcers. This can be corrected by protecting the stomach from the increased acidic content with PPI drugs and proper diet by avoiding acidic and spicy foods. On the other hand, Risperdal is a medication used to treat stress and depression can also cause dyspepsia and stomach discomfort. And same like sulfasalazine drug it can cause ulcer complications and even being the cause of developing peptic ulcers. Both these drugs have many other side effects like tiredness, fatigue, and flu-like symptoms which are considered minor if you think about the good impact they have in treating arthritis. Pay attention if important symptoms of fever, tremors, muscle spasms and mental changes appear. If so it is due to Risperdal the cause. Difficulty with urination, skin changes and flu symptoms can be more due to sulfasalazine drug. You can consult with the doctor who has your father in charge the option of changing the drugs with some other options that cause fewer stomach troubles. Hope this was helpful. Dr.Albana