Malaria Prophylaxis with Hydroxychloroquine

Clinical Context and Limitations

Hydroxychloroquine is interchangeable with chloroquine for malaria prophylaxis in areas without chloroquine resistance, with both drugs rarely causing serious adverse reactions at prophylactic doses, according to the Centers for Disease Control and Prevention (CDC) 1, 2, 3
The CDC recommends mefloquine (250 mg weekly for adults) as a first-line alternative in areas with high chloroquine resistance 4
The CDC also recommends doxycycline as an alternative for short-term travelers or in mefloquine-resistant areas, and atovaquone-proguanil for areas with chloroquine resistance 1, 4

The CDC recommends periodic ophthalmologic examinations for persons using hydroxychloroquine for extended periods (>6 years cumulative weekly prophylaxis) 2, 3
Hydroxychloroquine may exacerbate psoriasis, interfere with antibody response to intradermal human diploid cell rabies vaccine, and has a risk of retinopathy with daily doses exceeding 5 mg/kg actual weight 2, 3

The CDC advises that most malaria deaths occur in travelers who do not fully comply with prophylaxis regimens, and emphasizes the importance of starting prophylaxis 2 weeks before travel and continuing for the full 4 weeks after leaving the endemic area 4
The World Health Organization (WHO) notes that hydroxychloroquine does not prevent relapses from P. vivax or P. ovale liver stages, and recommends primaquine prophylaxis during the last 2 weeks of the 4-week post-exposure period after G6PD testing 1
No prophylactic regimen guarantees complete protection, and the CDC advises patients to use insect repellents, wear protective clothing, and seek immediate medical evaluation if fever develops during or after travel 4

In sub-Saharan Africa, where 80% of U.S. civilian malaria cases were acquired during 1980-1988, chloroquine-resistant P. falciparum is common, making alternative agents necessary, as recommended by the CDC, based on MMWR Recommendations and Reports 5

For travelers unable to take mefloquine, options include doxycycline alone or chloroquine with standby Fansidar treatment available while seeking medical evaluation for febrile illness, as suggested by the CDC, based on MMWR Recommendations and Reports 5
Doxycycline serves as an alternative for short-term travelers or in mefloquine-resistant areas of East Asia, according to the BMJ 6

When chloroquine is used in non-resistant areas, the standard dose is 300 mg base weekly, starting 1-2 weeks before travel and continuing for 4 weeks after leaving the endemic area, as recommended by the BMJ 6