What is the prophylactic dosing schedule of atovaquone‑proguanil (Malarone) for a healthy adult traveler, including start and stop timing and adjustments for children, pregnancy, lactation, or renal/hepatic dysfunction?

Malarone Dosing for Travel Prophylaxis

For healthy adult travelers, take one adult-strength Malarone tablet (250 mg atovaquone/100 mg proguanil) daily, starting 1-2 days before entering a malaria-endemic area, continuing daily throughout the stay, and for 7 days after leaving the endemic region. 1

Standard Adult Dosing Schedule

• Pre-travel: Begin 1-2 days before arrival in malaria-endemic area 1
• During travel: One adult tablet (250 mg atovaquone/100 mg proguanil) daily 1
• Post-travel: Continue for 7 days after departure from endemic area 1
• Timing: Take at the same time each day with food or a milky drink to enhance absorption 1
• If vomiting occurs: Repeat the dose if vomiting happens within 1 hour of taking the medication 1

Pediatric Dosing (Weight-Based)

The CDC provides specific weight-based dosing for children using pediatric tablets (62.5 mg atovaquone/25 mg proguanil): 2

• 11-20 kg: 1 pediatric tablet daily 2
• 21-30 kg: 2 pediatric tablets daily 2
• 31-40 kg: 3 pediatric tablets daily 2
• >40 kg: 1 adult tablet daily (same as adult dose) 2

The same timing schedule applies (start 1-2 days before, continue during, and 7 days after travel). 1

Renal Impairment Adjustments

• Mild to moderate impairment (creatinine clearance 30-80 mL/min): No dose adjustment needed 1
• Severe impairment (creatinine clearance <30 mL/min): Do not use for prophylaxis 1
• Dialysis patients: Malarone is contraindicated for prophylaxis 1

Hepatic Impairment Adjustments

• Mild to moderate impairment: No dose adjustment required 1
• Severe impairment: No studies available; use with extreme caution 1

Pregnancy and Lactation

• Pregnancy: Malarone is not recommended during pregnancy 3
• Pregnant women should avoid travel to chloroquine-resistant malaria areas entirely 3
• If travel is unavoidable, chloroquine plus proguanil is the safer alternative despite limited efficacy 3
• Lactation: Small amounts transfer to breast milk, but insufficient to protect the infant; the nursing infant requires their own prophylaxis at appropriate pediatric doses 3

Critical Pitfalls to Avoid

• Food requirement: Atovaquone absorption increases 2-3 fold with dietary fat; always take with food or milk 4
• Compliance: Taking the medication daily without missing doses is essential for protection 5
• Post-travel continuation: The 7-day post-travel period is critical as both atovaquone and proguanil act against liver stages of the parasite 5
• Pediatric overdose risk: Malarone can be fatal in overdose; store in child-proof containers out of children's reach 3

Evidence on Abbreviated Regimens

While some observational studies suggest stopping Malarone 1 day after leaving endemic areas may be effective 6, 7, a systematic review concluded that the quality and sample size of studies supporting the standard 7-day post-travel regimen far outweigh those supporting abbreviated schedules 8. Early discontinuation risks atovaquone monoprophylaxis and potential resistance development 8. The FDA-approved regimen remains 7 days post-travel. 1