This section is from the book "Botanic Drugs Their Materia Medica, Pharmacology and Therapeutics", by Thomas S. Blair. Also available from Amazon: Botanic Drugs, Their Materia Medica, Pharmacology and Therapeutics.
Poison Hemlock, Conium maculatum. Deleted from the ninth U. S. P., but included in the National Formulary. Official in Austria, France, Mexico, and Spain. Preparations rapidly deteriorate.
Coniine is the principal alkaloid, and its action is intermediate between nicotine and curarine. It causes profuse salivation and a rise in blood pressure. May give rise to ganglionic paralysis. Death is from respiratory paralysis.
The symptoms of a poisonous dose are drowsiness, uncertain gait, muscular relaxation, vomiting, salivation, convulsions. The mind remains clear.
Never give coniine; it is too dangerous. Perhaps an exception may be made as regards tetanus, when 1-20 to 1-10 grain coniine hydrobromide may be given hypodermically, repeating the dose with care; but don't neglect anti-tetanic serum and proper surgery.
Fresh fluid preparations have given results in chorea, paralysis agitans, delirium tremens, and other spasmodic affections, as well as in visceral pain and the pain of cancer. The dose is experimental in each case, usually about 3 minims fl.
The drug is uncertain and unreliable and is going out of use. Use gelsemium in its place.