Malaria Prophylaxis Dosing Recommendations
For chloroquine-sensitive areas, use chloroquine 300 mg base weekly; for chloroquine-resistant regions, use atovaquone-proguanil 250/100 mg daily, doxycycline 100 mg daily, or mefloquine 250 mg weekly as first-line options. 1
Standard Prophylaxis Regimens by Drug
Chloroquine (for chloroquine-sensitive areas only)
- Adults: 300 mg base (500 mg salt) once weekly 2
- Children: Dose based on body weight, proportional to adult dose 1
- Timing: Start 1-2 weeks before travel, continue weekly during travel, and for 4 weeks after leaving the malarious area 1, 3
Atovaquone-Proguanil (First-line for chloroquine-resistant areas)
- Adults: 250 mg atovaquone/100 mg proguanil (1 tablet) once daily 4
- Children: Weight-based dosing: 11-20 kg (1/4 tablet), 21-30 kg (1/2 tablet), 31-40 kg (3/4 tablet), >40 kg (1 adult tablet) 4, 5
- Timing: Start 1-2 days before travel, continue daily during travel, and for only 7 days after leaving the malarious area 1, 4
- Key advantage: Shortest post-travel duration due to activity against liver stages 4
Doxycycline (Alternative for chloroquine-resistant areas)
- Adults: 100 mg once daily 6, 7
- Children >8 years and >45 kg: 100 mg once daily 7
- Children >8 years and <45 kg: 2 mg/kg once daily (up to adult dose) 7
- Timing: Start 1-2 days before travel, continue daily during travel, and for 4 weeks after leaving the malarious area 1, 6, 7
- Critical contraindications: Pregnancy, lactation, children <8 years 2, 6
Mefloquine (Alternative for chloroquine-resistant areas)
- Adults: 250 mg (228 mg base) once weekly 1
- Children >15 kg: Weight-based dosing proportional to adult dose 2
- Timing: Start 1-2 weeks before travel, continue weekly during travel, and for 4 weeks after leaving the malarious area 1
- Contraindications: History of seizures, epilepsy, psychiatric disorders, cardiac conduction abnormalities, pregnancy, children <15 kg, tasks requiring precision movements (e.g., pilots) 2, 1
Proguanil (Combined with chloroquine in areas of limited resistance)
- Adults: 200 mg daily in combination with weekly chloroquine 300 mg base 2
- Efficacy note: Provides substantial but less protection than mefloquine; limited efficacy in sub-Saharan Africa and Southeast Asia 2
Primaquine for Relapsing Malaria Prevention
Terminal Prophylaxis Against P. vivax and P. ovale
- Adults: 30 mg base daily for 14 days 1
- Timing: Administer during the last 2 weeks of the standard 4-week post-exposure prophylaxis period 2, 1
- Indication: Primarily for prolonged exposure (missionaries, Peace Corps volunteers) 2
- Mandatory prerequisite: G6PD testing before use; absolutely contraindicated in G6PD deficiency and pregnancy 1, 3
Critical Timing Principles
Pre-Travel Initiation
- Chloroquine and mefloquine: Start 1-2 weeks before departure to establish blood levels and assess tolerance 1
- Doxycycline and atovaquone-proguanil: Can start 1-2 days before travel 1, 7
Post-Travel Duration
- Most regimens: Continue for 4 weeks after leaving the malarious area 1, 3
- Atovaquone-proguanil exception: Only 7 days post-travel due to causal prophylactic activity against liver stages 1, 4
Special Population Considerations
Pregnancy
- Chloroquine is the safest option for pregnant women 1, 3
- Carry Fansidar (sulfadoxine-pyrimethamine) for presumptive self-treatment if fever develops and medical care is unavailable 2, 1
- Mefloquine, doxycycline, and primaquine are contraindicated 2, 1, 6
Children
- <15 kg: Chloroquine only; mefloquine contraindicated 2, 1
- <8 years: Doxycycline contraindicated 6, 7
- ≥11 kg: Atovaquone-proguanil can be used with weight-based dosing 4
Common Pitfalls to Avoid
Compliance Failures
- Most malaria deaths occur in travelers who do not fully comply with prophylaxis regimens 2, 3
- Never stop prophylaxis early, even if feeling well; continue for the full post-exposure period 1
Drug-Specific Adverse Effects
- Mefloquine neuropsychiatric effects: Occur in first three doses (70% of cases); discontinue immediately if severe mood changes, hallucinations, or seizures develop 2, 1
- Doxycycline photosensitivity: Can be severe and prolonged; avoid excessive sun exposure 2, 6
- Chloroquine retinopathy: Periodic ophthalmologic exams recommended after >6 years cumulative weekly prophylaxis 2, 3