Hydroxychloroquine belongs to a class of medicines called disease modifying anti-rheumatic drugs (DMARDs). DMARDs reduce symptoms such as pain and swelling and slow down the progress of certain autoimmune diseases (disease where the body's natural defence system attacks own body cells) such as:

• Rheumatoid arthritis
  
• Systemic lupus erythematosus
• Systemic sclerosis
• Sjögren syndrome

In the long term, it reduces permanent damage to the organs such as joints, lung and skin. It may be used on its own or in combination with other DMARDs or biologic agents.