Quinine was the first treatment for malaria, known from 1631 in Europe, and probably much earlier to the native peoples of South America. Even today, quinine is used to treat certain forms of malaria, when other drugs fail or are unavailable. In that way, quinine is currently one of the best treatments for "malaria tropica", which is caused by plasmodium falciparum. For the other forms of malaria, quinine is no longer used, as other drugs have replaced it.