LOBAR PNEUMONIA. See PNEU MONIA.
LOBELIA.—Lobelia is the dried leaves and tops of the Lobelia inflata, or Indian tobacco, a weed indigenous to the -United States, collected after a portion of the capsules have become inflated. It is a small herb, with alternate leaves, an erect hairy stem, with blue flowers in the axils of the leaves. The herb has a slightly irritating odor, and a burning, tobacco like taste. It contains a liquid alkaloid, lobeline, and an acid, lobelic acid; gum resin, fixed oil, lignin, salts, chlorophylle, and a volatile oil.
Preparation and Doses.—Lobelia, 1 to 10 grains. Extractum lobelice fluidum, 1 to 5 minims (10 to 30 minims—emetic). Tinctura lobeliw, 8 to 15 minims (30 to 60 minims—emetie).
Physiological Action.—Excessiye doses of lobelia give rise to nausea, violent vomiting, cold sweats, pallor, marked prostration, muscular weakness, and oc casionally purging. If the drug is not, in part, vomited, all these symptoms in crease in intensity and the patient falls into collapse, soon followed by death. These phenomena bear out the prevail ing view that paralysis of the motor nerves is the predominant influence of the drug when taken in poisonous doses. Dresser found that lobelia and its alka loid, lobeline, stimulated the anterior section of the spinal cord. In frogs lobe line causes loss of co-ordination and dis turbances of respiration. Ott observed that there occurred at first an immediate fall of arterial pressure, then a rise: a re sult apparently ascribable to the asphyxia induced through the influence of the drug upon the respiratory centres. Fur ther experiments showed, however, that the rise of pressure was, in part, clue to peripheral vasomotor stimulation. In therapeutics, therefore, the cardinal points to be borne in mind are that the effects of lobelia are primarily exerted upon the respiratory centres, the effects upon the vasomotor system and the cir culation being secondary factors.
Lobeline is a respiratory poison, as warm-blooded animals succumb to pa ralysis of respiration. In dogs it pro
duces loss of voluntary inovements and a concomitant exaggeration of the reflexes. Later, it produces paralysis of motor nerves, like curara. As it paralyzes the cardiac branch of the pneumogastric nerves, it may be included under the nicotine group. Lobeline causes an ac celeration of the respiratory movements, which is more persistent when the vagi are intact. Further, it augments the power of the respiratory muscles. Small doses suppress the inhibitory- influence of the pneumogastrics on the heart. 'While it stimulates the respiratory functions, it does not depress the system like hydro cyanic acid, and in energy it even sur passes aspidosperrnine. H. Dresser (Arch. f. exper. l'ath. u. _Pharm., B. 26, H. 3, 4, '90).
At first lobeline causes an increased secretion of the sudoriferous glands, these effects lasting from five to six minutes. This increase is followed by a decrease, which, although not so pronounced as that produced by atropine, lasts for sev eral hours. P. Aubert (Lyon I1I6d., Dec., '93).
Poisoning by Lobelia.—The symptoms of poisoning by lobelia or its alkaloid— lobeline—are much the same as those due to tobacco poisoning. Giddiness, faintness, trembling of the limbs, clammy sweats, frequent and prolonged vomiting accompanied by the most intense pros tration, violent abdominal and ageal pains, with occasional purging.
The pulse, at first weak, becomes almost imperceptible. The breathing becomes shallow and difficult. The vision is affected. Stupor is followed by coma or convulsions, more or less paralysis, col lapse, and death by paralysis of the mus cles of respiration. Vomiting is sionally absent, and then the tional symptoms are accentuated, and death is apt to follow. One drachm of the powdered leaves has proved fatal in about thirtv-six hours. On post-mortem examination the brain was found con crested and the 0-astric mucous membrane inflamed.