 While small amounts of ibogaine are found in "Voacanga Africana" root bark, they do not occur in sufficient quantity to have medicinal or psychoactive effects.Extracts from the plant are also used in the production of vinpocetine, a medication used to treat Alzheimer's disease, and vinblastine, used to treat leukemia.The 1998 "Encyclopedia of Psychoactive Plants" by Christian Rätsch included an entry on the "Voacanga" genus, which claimed that various members of the genus are used in West Africa for their psychoactive effects.