For the suppressive and chemoprophylaxis treatment of acute attacks of malaria, discoid, systemic lupus erythematous and rheumatic arthritis.

Hydroxychloroquine, a 4-aminoquinoline derivative, is an antimalarial agent. It is a blood schizonticidal agent and is active against asexual erythrocytic forms of most strains of Plasmodium malariae, P. ovale, P. vivax, and susceptible P. falciparum. The exact mechanism of antimalarial activity of hydroxychloroquine and the mechanism(s) of action of the drug in the treatment of rheumatoid arthritis and lupus erythematosus have not been determined.

Hydroxychloroquine is distributed into human milk. Hydroxychloroquine is partially metabolized; the major metabolites are desethylhydroxychloroquine and desethylchloroquine. Bisdesethylchloroquine, a carboxylic acid derivative, is also formed in small amounts. The excretory patterns are not well characterized, but hydroxychloroquine and its metabolites are slowly excreted by the kidneys.

In the presence of retinal or visual field change attributable with known 4-aminoquinoline compounds, patients with known hypersensitivity to 4-aminoquinoline compounds, for long- term therapy in children.

Hydroxychloroquine can cross the placenta. Caution should be exercised when using higher doses 400 mg, and hydroxychloroquine should be avoided during pregnancy. <20240213>

Avoided; because of the slow elimination rate and the potential for accumulation of a toxic amount in the infant.

Mild and transient headache, dizziness and GI complain (diarrhea, anorexia, nausea, abdominal cramps, rarely vomiting) may occur.
Precautions
1.Hepatic: Hepatotoxicity has been reported in patients with the use of hydroxychloroquine in some case. Monitoring recommended and therapy interruption may be necessary.
2. Reactivation of hepatitis B: There have been reports of reactivation of hepatitis B virus in patients receiving hydroxychloroquine in combination with other immunosuppressive agents.
3. Cardiovascular: In some cases cardiomyopathy was associated with phospholipidosis without inflammation, infiltration, or necrosis. Monitoring recommended and discontinue use if suspected.
4. Musculoskeletal: Skeletal muscle myopathy associated with phospholipidosis has been reported; monitoring recommended with long-term therapy.
5.Renal: Proteinuria with or without moderate reduction in glomerular filtration rate has been reported; discontinue if renal toxicity is suspected.
6. Ophthalmic: Irreversible retinal damage has been reported. Monitoring recommended, even after discontinuation of therapy.
7. Hematologic: Use caution in patients with glucose-6-phosphate dehydrogenase deficiency <20240213>

Adults: For malaria, as a suppressive 400mg QW; for therapy, initially 800mg, followed by 400mg in 6-8 hours, and 400mg QD on 2nd and 3rd days.
For lupus erythematous: 200 - 400mg QD or BID.
For rheumatoid arthritis: 400-600mg QD to start taken with food or milk, until remission occurs, then 200-400mg QD for maintenance.
Children:
For malaria, as suppressive: 5mg (calculated as base)/kg, not exceed the adult dose regardless of weight; for therapy: initially 10mg/kg be taken in two divided doses 6 hours apart. The suppressive therapy should be continued for 8 weeks after leaving the endemic area.