HCQS 400 or OXCQ 400 contains Hydroxychloroquine, which is an arthritis medicine that can also be given to prevent malaria. It can be recommended to adults and children of all ages. Hydroxychloroquine is extremely effective as suppressive treatment and for treating acute attacks of malaria due to plasmodium vivax, P malariae, etc. The medicine is also useful in treating systematic lupus erythematosus and rheumatoid arthritis. The medicine is safe to use by pregnant women and nursing mothers. People with psoriasis should not take OXCQ tablets.

For adults, 400 mg once a week starting two weeks before exposure and continued for four weeks after leaving the endemic area.  For paediatrics, do not exceed 400 mg once a week starting two weeks before exposure and should continue for four weeks after leaving the endemic area. 

For the treatment of adults with Lupus erythematosus, the recommended dose is 400mg daily. Doses above 400 mg are not recommended. There is an increased risk of retinopathy when the maintenance dose is exceeded. 

For rheumatoid arthritis, the initial adult dosage is 400mg daily. In very few people, side effects may require a temporary reduction of the initial dosage. Discuss with your doctor for the maintenance dose because when a good response is obtained, the dosage may be reduced and continued as a maintenance dose. There are no limits on the use of Hydroxychloroquine for the prevention of malaria. A rare eye condition called retinopathy has occurred when this medication is used at a higher dose for many years. People who have been receiving this medication for more than five years should get regular eye exams. People already using HCQS 400 or OXCQ 400 for arthritis may not need to take an additional dose to prevent malaria.

The use of Hydroxychloroquine is contraindicated in patients with retinal or visual field changes, known hypersensitivity to Hydroxychloroquine and long-term therapy in children. The medicine is not effective against chloroquine-resistant strains of P.falciparum. HCQS 400 or OXCQ 400 may precipitate a severe attack of psoriasis in patients with psoriasis. When taken by patients with porphyria, the condition may be worsened. The tablets should not be consumed in these conditions unless advised by the doctor. Its use during pregnancy should be avoided except in the suppression or treatment of malaria when the doctor found the benefit outweighs the possible hazard. Antimalarial compounds should be used with caution in liver disorders and alcoholism or combined with known hepatotoxic medications. If any severe blood disorder appears, discontinuation of the treatment should be considered. The medicine should be used with caution in patients having glucose-6-phosphate dehydrogenase deficiency. 

HCQS 400 or OXCQ 400 is a relatively well-tolerated medicine. The most common side effects are stomach nausea, vomiting, headache, and stomach pain. These side effects can often be reduced by taking the medication with food. Minor side effects associated with the use of this drug include nausea, occasional vomiting, or diarrhoea. These side effects do not usually do not require discontinuation of antimalarial drugs.