Chloroquine (Lariago) Dosage for Malaria Treatment and Prophylaxis
For treatment of uncomplicated malaria, chloroquine phosphate (Lariago) should be administered at a total dose of 25 mg/kg base (41.7 mg/kg salt) over 3 days, with specific dosing of 10 mg/kg base initially, followed by 5 mg/kg at 6,24, and 48 hours. 1, 2
Treatment Dosage for Uncomplicated Malaria
Adults:
- Initial dose: 600 mg base (1000 mg salt/phosphate)
- Followed by 300 mg base (500 mg salt/phosphate) at 6 hours
- Then 300 mg base (500 mg salt/phosphate) at 24 hours
- Then 300 mg base (500 mg salt/phosphate) at 48 hours
- Total dose: 1500 mg base (2500 mg salt/phosphate) 2
Children:
- Initial dose: 10 mg base/kg (not exceeding 600 mg base)
- Followed by 5 mg base/kg (not exceeding 300 mg base) at 6 hours
- Then 5 mg base/kg at 24 hours
- Then 5 mg base/kg at 48 hours
- Total dose: 25 mg base/kg 3, 2
Prophylaxis Dosage (for chloroquine-sensitive areas)
Adults:
- 500 mg salt (300 mg base) once weekly
- Begin 1-2 weeks before travel to malarious areas
- Continue weekly during travel and for 4 weeks after leaving malarious areas 3, 2
Children:
- 5 mg base/kg body weight (8.3 mg salt/kg) once weekly
- Should not exceed adult dose regardless of weight
- Same schedule as adults (1-2 weeks before, during, and 4 weeks after travel) 3, 2
Important Administration Considerations
For treatment: If supervised therapy during the 3-day period is not possible, the first dose should be given under supervision and additional doses may be given to the patient with appropriate instructions 3
Monitoring: Patients who remain symptomatic longer than 3 days into therapy should have a repeat blood smear examined. Alternative therapy should be instituted if parasitemia has not diminished markedly by this time 3, 1
Special populations: Pregnant women can safely take chloroquine during pregnancy, following the adult dosing regimen 3, 1
Resistance Considerations
In areas with known chloroquine resistance, alternative treatments should be used:
- For treatment: artemether/lumefantrine or other artemisinin-based combination therapies 1
- For prophylaxis: mefloquine, doxycycline, or atovaquone-proguanil 3
Common Side Effects and Management
- Gastrointestinal disturbances (nausea, vomiting)
- Pruritus
- Headache, dizziness
- Postural hypotension
Management tip: Taking chloroquine with meals or in divided twice-weekly doses may improve tolerability 3
Cautions
Before using primaquine for radical cure of P. vivax or P. ovale, G6PD status must be verified to prevent potentially life-threatening hemolysis 3
Higher doses of chloroquine (50-70 mg/kg) have been studied for resistant strains but should only be used under specialist supervision due to potential QT interval prolongation 4
Suboptimal dosing is common when using age-based regimens rather than weight-based dosing, which can lead to treatment failure and promote resistance 5