by 1953, name for human anti-coagulant use of the rat poison warfarin sodium, abstracted from the chemical name, 3-(α-acetonylbenzyl)-4-hydroxycoumarin; earlier known as Dicoumarol, it attained publicity when it was used in 1955 to treat U.S. President Dwight Eisenhower after a heart attack. The coumarin element (1830) is from French coumarine, from coumarou, the native name in Guyana of the tonquin bean, one source of the substance.