HCQS 200 Tablet contains Hydroxychloroquine (200mg), a medication commonly used to treat autoimmune conditions such as rheumatoid arthritis, lupus (systemic lupus erythematosus), and certain skin disorders. Hydroxychloroquine works by modulating the immune system and reducing inflammation, which helps to alleviate symptoms like joint pain, swelling, and skin rashes. It is also used as part of the treatment for malaria, although it is not typically the first choice for this purpose. Common side effects include nausea, stomach pain, and headache. Long-term use may require regular monitoring for potential side effects on the eyes, as Hydroxychloroquine can, in rare cases, affect the retina, leading to vision problems. It is important to follow the prescribed dosage and attend regular follow-up appointments to monitor for any side effects, especially if used for extended periods.