Hydroxychloroquine, i.e. Hydroxychloroquine Sulfate Tablets, the possible harmful effects of long-term use mainly include central nervous system such as dizziness, deafness, etc.; neuromuscular system such as muscle aches and pains, weakening of neural reflexes; skin such as rashes, alopecia, etc.; eyes such as blurred vision, visual field defect, etc.; cardiovascular system such as cardiac conduction abnormalities. Hydroxychloroquine Sulfate Tablets are mainly used for the treatment of systemic lupus erythematosus, cutaneous lupus, rheumatoid arthritis and so on. Long-term use of hydroxychloroquine sulfate may have certain effects on various body systems. 1. Central nervous system: such as headache, dizziness, tinnitus, deafness and so on. 2. Neuromuscular system: the more common ones include convulsions, muscle aches and pains, and weakened knee tendon reflexes. 3. Skin: e.g. itchy skin, rash, hair loss, etc. 4. Eye: such as blurred vision, visual field defects, photophobia, corneal edema, and so on. 5. Cardiovascular system: cardiac conduction abnormalities, etc. Most of the side effects of hydroxychloroquine sulfate tablets are reversible, and most of them can disappear gradually after stopping the drug. If the above side effects occur, it is necessary to consult the Department of Rheumatology and Immunology in time to adjust the treatment program. Hydroxychloroquine Sulfate Tablets must be used under the guidance of a doctor and followed up regularly during the use of the drug.