Hetquenil 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 exerts its therapeutic effects by interfering with lysosomal activity and autophagy, modulating immune system activity, and inhibiting the replication of certain intracellular pathogens. Hetquenil 300 is indicated for the prevention and treatment of acute attacks of malaria caused by Plasmodium species, as well as for managing autoimmune conditions such as rheumatoid arthritis and lupus erythematosus to reduce inflammation and prevent disease progression. The medication should be administered under medical supervision, with dosage tailored to the specific condition and patient response. Common adverse effects may include gastrointestinal disturbances, headache, dizziness, and skin rash, while rare but serious side effects include retinopathy and cardiomyopathy; therefore, regular ophthalmologic and cardiac monitoring is recommended during prolonged therapy. Caution is advised in patients with pre-existing retinal or cardiac conditions, and it is contraindicated in individuals with hypersensitivity to hydroxychloroquine or related compounds. Hetquenil 300 Tablet should be used with caution during pregnancy and lactation, with benefits and risks carefully evaluated by the prescribing physician.