Hi & Welcome to HCM. Incomplete data like age, gender, etc. However, I can understand your concern. There s no harmful interaction between the two prescribed medications for rheumatoid arthritis. But, the use of Hydroxychloroquine is known to cause certain important side effects like blurring of the vision due to corneal deposits or retinopathy. You need to have periodic ophalmoscopic (eye) examination to detect this side effect. You should not continue Hydroxychloroquine once you develop these side effects. Other side effects including gryeing of the hairs, vomiting, ringing in the ears, vertigo etc. Hope this answers your query.