Old drug, new use

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