This section is from the "A Handbook of Useful Drugs" book, by State Medical Examining and Licensing Boards.
The tuberous root of Aconitum napellus L.
Action and Uses: Aconite slows the pulse and thus lowers the blood-pressure. The nervous system is first stimulated and then depressed. Death occurs from respiratory paralysis. Locally applied, aconite causes paralysis of the sensory nerve endings.
Aconite is used internally as a cardiac depressant, anti-pyretic and diaphoretic, especially in sthenic fevers of short duration or in the initial stage only of other diseases. It should be avoided in fevers accompanied by cardiac weakness. The danger from the depressing action of aconite on the heart makes it an undesirable agent to use as a cardiac depressant. It is being used less and less.