Coto bark contains a volatile alkaloid, a pungent aromatic volatile oil, a light brown soft resin, and a hard brown resin, starch, gum, sugar, tannin, Cal. Oxalate and three acids, acetic, butyric and formic. Coto bark is irritating to the skin applied externally. If taken internally it gives constant violent pain and vomiting. Its chief use is in diarrhoea, but it has a tendency to produce inflammation, so must be used with great caution, it is said to lessen peristaltic action.
Paracota bark resembles it in action, but is much less powerful.
In Japan, paracota bark has been successfully employed for cholera by hypodermic injection of 3 grains of paracotoin. The value of cotoin in diarrhcea is established, and it is also used for catarrhal diarrhoea and for diarrhcea in tubercular ulceration of typhoid fever. Has also a specific action on the alimentary canal, dilating the abdominal vessels and hastening absorption.