Ipecacuanha: the South American vomiting root

The story of ipecacuanha, derived from the plant Cephaelis, is a fascinating one. It was discovered in Brazil in the 1600s and then transported to Paris in the latter part of the same century. It was used there by the physician Helvetius on various members of the French royal court to treat the flux (dysentery) with some success. Later, in the eighteenth century, it was taken up by the physician and privateer Thomas Dover and became, with opium, a fundamental constituent of his celebrated powder, which was used widely to treat fevers and agues for the next 200 years. Progress was then delayed until the early 1800s when the School of Chemistry at Paris established that the dried root of ipecac contained two powerful alkaloids, emetine and cephaeline, that consistently caused vomiting and diarrhoea. The discovery of the pathogenic amoeba, Entamoeba histolytica, in the latter part of the nineteenth century, allowed a distinction to be made between the two main forms of dysentery (amoebic and bacillary). Emetine was shown to be active against the amoebic form of dysentery but ineffective against that caused by bacteria. Ipecacuanha, its root and the pure alkaloid emetine have now been abandoned on the grounds of toxicity. They have been replaced by safer, more effective compounds. Nevertheless, they deserve an honoured place in the history of medicine, especially in the search for an effective treatment for amoebic dysentery.