Lobelia, in the ordinary sense of the term, is not a poison. Undoubtedly, its injudicious use has, and might produce death, but the same is true of many other drugs that are not ordinarily considered as poisons. That the alkaloid lobeline will kill animals, has been fully demonstrated. A drop of the alkaloidal solution placed upon the tongue of a strong, healthy man, instantly vomited him. To this property of its alkaloid, is undoubtedly due the failure of lobelia to act as a toxic agent. Its emetic action is so prompt and decided, that the contained alkaloid could not, under ordinary circumstances, produce fatal results. Given in cases in extremis, the resulting exhaustion from repeated emesis would very likely hasten death, but death would be more likely due to the act of vomiting exhausting the patient, than to any poisonous effect of the medicine.
If lobelia be chewed, it gives rise to an acrid, prickling, and persistently pungent sensation in the throat and fauces, accompanied by slight nausea and a feeling of warmth and distension along the esophageal tract and in the stomach. The sensation is not very unlike that produced by tobacco. The salivary and buccal glands are impressed, pouring out saliva and mucus in abundance. A sense of epigastric depression succeeds, followed by profound nausea, and if the amount chewed be large enough, severe and thorough emesis results. The gastric mucus is secreted in great abundance and ejected with the contents of the stomach. The emetic action of lobelia is extremely depressing, and is usually accompanied by profuse perspiration. Oppressive prostration, relaxation of the muscular system, and a languid pulse accompany the emetic stage. The depression, however, is of short duration, and is immediately followed by a sense of extreme satisfaction and repose. Under its action the mental powers are unusually acute, and the muscles are powerfully relaxed. The circulation is enfeebled by large and strengthened by small doses, and the bronchial secretions are augmented. When the drug does not prove emetic, it is said that it usually purges. Death, when due to lobeline, is said to result from respiratory paralysis.