<unk>  is a drug used to treat malaria.<unk> 's structure contains a substituted phenanthrene, and is related to the antimalarial drugs quinine and lumefantrine. Marketed as Halfan,<unk>  is never used to prevent malaria and its mode of action is unknown, although a crystallographic study showed that it binds to hematin in vitro, suggesting a possible mechanism of action.<unk>  has also been shown to bind to plasmpesin, a haemoglobin degrading enzyme unique to the malarial parasites.<unk>  was developed at SRI International for the Walter Reed Army Institute of Research from 1965 to 1975 by a team led by medicinal chemist William Colwell.
Halofantrine
Methylergonovine 
Midodrine
Bornaprine
Etilefrine
Terbutaline 
Iotrolan
Gepefrine