What agent is effective for chemoprophylaxis against most types of malaria among adults?

Chloroquine is widely recognized as a first-line agent for the prevention of most types of malaria in adults, particularly strains that are sensitive to it. This medication works by interfering with the parasite's ability to metabolize and utilize hemoglobin within the red blood cells, which ultimately inhibits its growth and reproduction.

Chloroquine is particularly effective against Plasmodium vivax and Plasmodium ovale, both of which are sensitive to this treatment, as well as against Plasmodium malariae. While some strains of Plasmodium falciparum have developed resistance to chloroquine, it remains a primary choice in areas where such resistance is not widespread.

For travelers or individuals at risk in areas of malaria transmission, chloroquine can be used effectively for chemoprophylaxis, provided they are in regions where chloroquine resistance is not a significant concern. It is typically administered in a regimen that starts one week before travel and continues through the duration of exposure, making it a convenient option for preventing malaria.

Other options may be used under specific conditions or against certain strains of malaria, but chloroquine’s broad effectiveness against various strains makes it a suitable choice for chemoprophylaxis among adults, especially in areas with a lower risk of