What is the preferred prophylactic medication for malaria in areas with resistant Plasmodium falciparum?

Mefloquine is the preferred prophylactic medication for malaria in areas with resistant Plasmodium falciparum due to its effectiveness against this strain. Resistance to chloroquine is common in many regions where malaria is endemic, rendering it ineffective for prevention in those areas. Mefloquine, on the other hand, continues to demonstrate efficacy against resistant malaria strains and is therefore the recommended choice for travelers to such regions.

Doxycycline can also be used for malaria prophylaxis, but it is not the first-line recommendation in areas known for chloroquine resistance. Atovaquone, while effective, is typically not utilized as a first-line prophylactic medication for malaria when other effective options like mefloquine are available.

Thus, when considering a medication for malaria prophylaxis in regions with the risk of resistant P. falciparum, mefloquine is often favored due to its proven effectiveness and established guidelines supporting its use.