From the Guidelines
Malaria prophylaxis should be taken by travelers to endemic regions, with the choice of medication depending on destination, resistance patterns, and individual factors, and should always include non-pharmacological measures such as insect repellent and bed nets. When considering malaria prophylaxis, it is essential to weigh the risks and benefits of different medications. According to the study by 1, chemoprophylaxis is a complex aspect of malaria prevention, with different recommendations for particular countries. The study highlights the importance of compliance, starting chemoprophylaxis one week before departure, and considering the availability and toxicity of certain medications. Some key points to consider when choosing a medication for malaria prophylaxis include:
- The destination and resistance patterns of the area
- The duration of travel and individual factors such as pregnancy or medical conditions
- The potential side effects and toxicity of certain medications, as noted in the study by 1
- The importance of non-pharmacological measures such as insect repellent and bed nets, as these can significantly reduce the risk of malaria infection. The study by 1 provides recommendations for the prevention of malaria among travelers, including the use of chloroquine alone for travel to areas of risk where chloroquine-resistant P. falciparum has not been reported. However, it is essential to consider the limitations of this study, given its publication in 1990, and to prioritize more recent and higher-quality evidence when making decisions about malaria prophylaxis. In terms of specific medications, options may include atovaquone-proguanil, doxycycline, mefloquine, or chloroquine, depending on the individual circumstances of the traveler. Ultimately, the goal of malaria prophylaxis is to prevent severe illness and death from malaria infection, and to minimize the risk of infection through a combination of pharmacological and non-pharmacological measures.
From the FDA Drug Label
Prevention of Malaria: Atovaquone and proguanil hydrochloride was evaluated for prophylaxis of malaria in 5 clinical trials in malaria-endemic areas and in 3 active-controlled trials in non-immune travelers to malaria-endemic areas Three placebo-controlled studies of 10 to 12 weeks' duration were conducted among residents of malaria-endemic areas in Kenya, Zambia, and Gabon. Of a total of 669 randomized patients (including 264 pediatric patients 5 to 16 years of age), 103 were withdrawn for reasons other than falciparum malaria or drug-related adverse events The results are listed in Table 6. Table 6. Prevention of Parasitemia in Placebo-Controlled Clinical Trials of Atovaquone and Proguanil hydrochloride for Prophylaxis of P falciparum Malaria in Residents of Malaria-Endemic Areas Atovaquone and proguanil hydrochloride Placebo Total number of patients randomized 326 341 Failed to complete study 57 44 Developed parasitemia (P falciparum) 2 92
Malaria Prophylaxis:
- Atovaquone and proguanil hydrochloride is effective for malaria prophylaxis, with a low incidence of parasitemia (2 out of 326 patients) compared to placebo (92 out of 341 patients) 2.
- The recommended dosage for prophylaxis is not explicitly stated in the provided text, but it can be inferred that atovaquone and proguanil hydrochloride is taken daily.
- Mefloquine is also used for malaria prophylaxis, with a recommended dosage of 250 mg once weekly, starting 1 week before arrival in an endemic area and continuing for 4 weeks after leaving the area 3.
From the Research
Malaria Prophylaxis Options
- Malaria is largely preventable, and travelers should be taught general protective measures and given appropriate chemoprophylaxis before they leave on their trip 4
- Chloroquine phosphate is still the drug of choice in locations where malaria remains chloroquine-sensitive, but chloroquine-resistant areas are becoming more numerous 4
- In chloroquine-resistant areas, mefloquine hydrochloride, doxycycline, or proguanil may be used 4
- Atovaquone-proguanil is a recommended option for malaria prophylaxis, with a lower frequency of treatment-related gastrointestinal adverse events compared to chloroquine-proguanil 5
Comparison of Malaria Prophylaxis Regimens
- Atovaquone-proguanil and doxycycline are the best tolerated regimens, while mefloquine is associated with adverse neuropsychiatric outcomes 6
- Mefloquine users are more likely to report abnormal dreams, insomnia, anxiety, and depressed mood compared to atovaquone-proguanil users 7
- Mefloquine users are also more likely to report nausea and dizziness compared to atovaquone-proguanil users 7
- Primaquine should be considered as the chemoprophylactic agent of choice for areas with high co-circulation of P. falciparum and P. vivax 8
Efficacy and Safety of Mefloquine
- Mefloquine is one of four antimalarial agents commonly recommended for preventing malaria in travelers to malaria-endemic areas 7
- Mefloquine has high efficacy, but there is controversy about its psychological side effects 7
- The choice of antimalarial agent depends on how individual travelers assess the importance of specific adverse effects, pill burden, and cost 7
Vivax Malaria Chemoprophylaxis
- Atovaquone-proguanil is considered causal prophylaxis for Plasmodium falciparum, but its causal prophylactic efficacy for Plasmodium vivax is not known 8
- Short-course atovaquone-proguanil appears to provide causal prophylaxis for P. vivax, but is ineffective against late, hypnozoite reactivation-related attacks 8