HYQ 300mg Tablet contains Hydroxychloroquine sulfate equivalent to 300mg of Hydroxychloroquine, an antimalarial and immunomodulatory agent. It is primarily indicated for the treatment and prevention of malaria caused by Plasmodium species. Additionally, HYQ 300mg is utilized in the management of autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus due to its ability to modulate the immune response and reduce inflammation. The mechanism of action involves interference with lysosomal activity and autophagy in immune cells, leading to decreased antigen presentation and cytokine production. HYQ 300mg is administered orally, with dosage tailored to the specific condition and patient response. Common adverse effects may include gastrointestinal disturbances, headache, dizziness, and skin reactions; however, serious adverse events such as retinopathy necessitate regular ophthalmologic monitoring during prolonged therapy. Caution is advised in patients with pre-existing retinal or visual field changes, hepatic or renal impairment, and those on concomitant medications that may prolong the QT interval. HYQ 300mg should be used under strict medical supervision, adhering to recommended dosing schedules to optimize therapeutic outcomes while minimizing potential toxicity.