Hydroxychloroquine Sulphate

Indications

Hydroxychloroquine Sulphate is used for: Acute and chronic rheumatoid arthritis, Systemic Lupus Erythematosus (SLE), Malaria

Adult Dose

Oral Malaria Acute treatment 800 mg PO, then 400 mg PO 6-8 hours later, then 400 mg PO at 24 and 48 hours Prophylaxis 400 mg PO weekly, starting 2 weeks before exposure and continued for 4 weeks after departure from area Rheumatoid Arthritis 400-600 mg PO daily for 4-12 weeks; maintenance: 200-400 mg PO daily Systemic Lupus Erythematosus 400 mg PO once or twice daily; maintenance: 200-400 mg PO daily Hepatic impairment: Estimation of plasma hydroxychloroquine levels to be undertaken in patients with severely compromised function and dosage adjusted accordingly.

Child Dose

Malaria Acute treatment 13 mg/kg base PO, then 6.5 mg/kg base PO 6 hr later, then 6.5 mg/kg base PO at 24 and 48 hours; not to exceed 400 mg/day base Prophylaxis 6.5 mg/kg base (not to exceed 400 mg [310 mg base]) PO weekly, starting 2 weeks before exposure and continued for 4 weeks after departure from area

Renal Dose

Renal impairment: Estimation of plasma hydroxychloroquine levels to be undertaken in patients with severely compromised function and dosage adjusted accordingly.

Administration

Should be taken with food.

Contra Indications

The presence of retinal or visual field changes attributable to any 4-aminoquinoline compound, patients with known hypersensitivity to 4-aminoquinoline compounds, long term therapy in children.

Precautions

Impaired liver or renal function, severe GI disorders, porphyria, psoriasis, neurological disorders especially a history of epilepsy, myasthenia gravis, G6PD deficiency, pregnancy, lactation. Monitor CBC in patients receiving prolonged therapy. Perform baseline and periodic 6-mth eye exams, test periodically for muscle weakness. Lactation: Drug is concentrated in breast milk (American Academy of Pediatrics committee states that it is compatible with nursing)

Pregnancy-Lactation

Interactions

Cimetidine may increase serum levels of hydroxychloroquine. Its absorption may be decreased by kaolin or Mg trisilicate. Avoid digoxin and alcohol. Increased risk of ventricular arrhythmias when used with halofantrine. Concurrent use with mefloquine may increase the risk of convulsions.

Adverse Effects

Side effects of Hydroxychloroquine Sulphate : Retinopathy, hair loss, photosensitivity, tinnitus, myopathy (long-term therapy). Psychosis, seizures, leucopenia and rarely aplastic anaemia, hepatitis, GI upsets, dizziness, hypokalaemia, headache, pruritus, urticaria, difficulty in visual accommodation. Loss of hair, bleaching of hair pigment, bluish-black pigmentation of the mucous membranes and skin, photosensitivity, tinnitus, reduced hearing, nerve deafness, neuromyopathy, and myopathy, including cardiomyopathy.

Mechanism of Action

Hydroxychloroquine is a 4-aminoquinoline antimalarial with actions similar to those of chloroquine but is mainly used in the treatment of SLE and rheumatoid arthritis. It interferes with digestive vacuole function within susceptible malarial parasites by increasing pH and interrupting with lysosomal degradation of Hb thus impeding normal cell function of sensitive parasites.