Sign up to make the most of YourDictionary
By signing in, you agree to our Terms and Conditions
We'll see you in your inbox soon.
Caffeine interferes with drugs that regulate heart rhythm, such as quinidine and propranolol (Inderal).
Later quinidine and cinchonidine were discovered, and subsequently several other alkaloids, but in smaller quantity.
The sulphate of quinine used in medicine may contain up to 3% of cinchonidine, but should be free from cinchonine, quinidine and cupreine.
The other alkaloids of cinchona bark - quinidine, cinchonidine, and cinchonine - also possess similar properties, but all are much less effective than quinine.