What are the recommended medications for malaria prophylaxis?

Recommended Medications for Malaria Prophylaxis

For travelers to malaria-endemic regions, the recommended prophylactic medication depends on the destination's chloroquine resistance status, with mefloquine being the first choice for areas with chloroquine-resistant P. falciparum, while chloroquine remains effective in areas without resistance. 1

Selection Algorithm Based on Destination

1. Areas without chloroquine-resistant P. falciparum:

• First choice: Chloroquine 300 mg base weekly
  • Begin 1-2 weeks before travel
  • Continue during travel and for 4 weeks after leaving malarious area
  • Well tolerated; may be taken with meals if side effects occur
  • Alternative: Hydroxychloroquine (if chloroquine not tolerated) 1

2. Areas with chloroquine-resistant P. falciparum:

• First choice: Mefloquine 250 mg weekly

  • Begin 1-2 weeks before travel
  • Continue during travel and for 4 weeks after leaving malarious area 1, 2

• Alternatives (if mefloquine is contraindicated):

  • Doxycycline 100 mg daily
    • Can begin 1-2 days before travel
    • Continue during travel and for 4 weeks after leaving malarious area 1, 3
  • Chloroquine weekly plus standby Fansidar (for pregnant women, children <15 kg) 1

Special Considerations

Pregnancy

• Pregnant women should avoid travel to malarious areas when possible
• If travel necessary: Chloroquine and proguanil have established safety records
• Mefloquine can be used in second and third trimesters 1

Renal Impairment

• Mefloquine or doxycycline preferred as they are primarily metabolized by the liver
• For patients requiring proguanil, adjust dosing based on creatinine clearance:

  • 60 ml/min: 200 mg daily

  • 20-60 ml/min: 150 mg daily
  • 10-20 ml/min: 100 mg daily
  • <10 ml/min: 50 mg alternate days 1

High-Risk Groups

• Asplenic travelers require meticulous precautions against malaria
• Travelers with G6PD deficiency should use caution with chloroquine due to risk of hemolysis 4

Dosing Information

Mefloquine

• Adult dose: 250 mg weekly
• Pediatric dose:

  • 45 kg: 1 tablet weekly

  • 30-45 kg: 3/4 tablet weekly
  • 20-30 kg: 1/2 tablet weekly 2

Doxycycline

• Adult dose: 100 mg daily
• Not recommended for children under 8 years
• Take with adequate fluid to reduce esophageal irritation
• Avoid excessive sun exposure due to risk of photosensitivity 3

Chloroquine

• Adult dose: 300 mg base weekly
• Pediatric dose: 5 mg/kg base weekly (not to exceed adult dose) 4

Common Pitfalls to Avoid

1. Inadequate timing: Begin prophylaxis before travel (1-2 weeks for most drugs, 1-2 days for doxycycline)

2. Premature discontinuation: Continue prophylaxis for 4 weeks after leaving malarious areas

3. Inappropriate drug selection: Using hydroxychloroquine instead of chloroquine in resistant areas (8.8 times less effective against resistant strains) 5

4. Self-treatment errors: Mefloquine should not be used for self-treatment due to side effects 1

5. Neglecting non-drug measures: Always combine chemoprophylaxis with mosquito bite prevention:

   • Use insect repellents containing DEET
   • Wear long-sleeved clothing
   • Use bed nets
   • Apply permethrin to clothing 1

6. Failure to consider P. vivax/P. ovale relapse: These species can cause relapse for up to 4 years after exposure due to liver stages 1

7. Ignoring drug interactions: Certain medications may interact with antimalarials (e.g., antacids with chloroquine, anticoagulants with doxycycline) 3, 4

Remember that no prophylactic regimen provides 100% protection. Any fever occurring during travel or within a year after return from a malarious area should be promptly evaluated for malaria, even in those who have taken appropriate prophylaxis 1, 6.