An antihistamine introduced in 1983 shows activity against malaria in mice. Researchers discovered the drug's activity by screening a library of more than 2,000 existing drugs, a strategy that could reveal alternative uses for already approved drugs against other diseases.
David J. Sullivan Jr. of Johns Hopkins University in Baltimore and his colleagues assembled the library—the largest yet reported—from more than 1,900 U.S.–approved drugs and 750 others approved abroad or used in human trials. They then looked for compounds that stop the growth of Plasmodium falciparum, the parasite that causes malaria in people.
The screening identified the antihistamine astemizole, which was removed from American and European markets in the late 1990s because of potential damage to the heart.
Sullivan and his coworkers tested the drug in infected mice. Astemizole reduced the number of parasites by 80 percent in mice infected with a strain sensitive to