H-Quine 300 Tablet contains Hydroxychloroquine 300 mg, an antimalarial and immunomodulatory agent commonly used in the treatment of malaria, rheumatoid arthritis, and systemic lupus erythematosus. Hydroxychloroquine acts by interfering with lysosomal activity and autophagy, as well as modulating the immune system response, thereby reducing inflammation and disease activity. It is indicated for the prevention and treatment of acute attacks of malaria caused by Plasmodium species and as a disease-modifying agent in autoimmune conditions. The tablet should be administered orally, with dosage adjusted based on the specific indication, patient weight, and clinical response. Common adverse effects include gastrointestinal disturbances such as nausea, vomiting, and abdominal pain, as well as headache and dizziness. Rare but serious side effects may involve retinopathy, necessitating regular ophthalmologic monitoring during prolonged therapy. Caution is advised in patients with pre-existing retinal or visual field changes, hepatic or renal impairment, and in those with hypersensitivity to the drug. H-Quine 300 should be used under medical supervision, with periodic evaluation to assess therapeutic efficacy and detect potential toxicity. It is contraindicated in patients with known hypersensitivity to Hydroxychloroquine or related compounds.