Chloroquine
Synonym :
Hydroxychloroquine
Mechanism :
Chloroquine phosphate is a 4-aminoquinoline compound for oral administration. Chloroquine is an antimalarial and amoebicidal drug. The drug possesses antimalarial actions and exerts a beneficial effect in lupus erythematosus (chronic discoid or systemic) and acute or chronic rheumatoid arthritis. The precise mechanism of action is not known.
Indication :
- Malaria (Vivax malaria)
- Amoebic liver abscess
- Juvenile idiopathic arthritis (JIA)
- Porphyria
- Systemic lupus erythematosus
- Discoid lupus erythematosus
- Polymorphic light eruptions
- Rheumatoid Arthritis
- Porphyria Cutaneous Tarda (off-label)
Contraindications :
Contraindicated in the presence of retinal or visual field changes attributable to any 4-aminoquinoline compound, in patients with known hypersensitivity to 4-aminoquinoline compounds, and for long-term therapy in children.
Dosing :
Malaria:
Oral.10 mg/kg as loading dose followed by 5 mg/kg after 6 hours. Then 5 mg/kg every 24 hours till total dose is 25 mg/kg.
Malaria Prophylaxis:
5 mg/kg base once PO a week. To be given 1-2 week before entering the area and to be continued for 4 weeks after return.
Other conditions:
5-6.5 mg/kg (Max: 400 mg) once daily. Adjusted according to plasma levels in severe renal and hepatic impairment.
Adverse Effect :
QT prolongation, nausea, diarrhoea, anorexia, abdominal cramps, irreversible retinal damage (rare), corneal opacities. skin rashes, pigmentary changes, bleaching of hair and hair loss, methemoglobinemia. Hydroxychloroquine may precipitate attacks of psoriasis.
Interaction :
Digoxin: Plasma digoxin levels may be increased.
Antacids: Absorption of hydroxychloroquine may be reduced by antacids. Hydroxychloroquine may also be subject to the known interactions of chloroquine even though specific reports have not appeared.
Ampicillin: Chloroquine significantly reduced the bioavailability of ampicillin. An interval of at least two hours between intake of this agent and chloroquine should be observed.
Cyclosporin: After introduction of chloroquine, a sudden increase in serum cyclosporin level has been reported. Therefore, close monitoring of serum cyclosporin level is recommended.
Renal Dose :
Dose in Renal Impairment GFR (mL/min)
| 20-50 | Dose as in normal renal function |
| 10-20 | Dose as in normal renal function |
| <10 | 50% of normal dose |
Dose in Patients undergoing Renal Replacement Therapies
| CAPD | Not dialysed. Dose as in GFR<10 mL/min |
| HD | Not dialysed. Dose as in GFR<10 mL/min |
| HDF/High flux | Unknown dialysability. Dose as in GFR<10 mL/min |
| CAV/VVHD | Not dialysed. Dose as in normal renal function |
Hepatic Dose :
Chloroquine concentrates in the liver. No dosage adjustments are recommended.