(Indian Tobacco.)

Origin. - The dried leaves and tops of Lobelia inflata L., collected after a portion of the capsules have become inflated. The plant is indigenous in the United States. Description and Properties. - As it appears in the market, lobelia consists of fragments of green leaves, stems, rather elongated dried flowers, and portions of the membranous capsules. The odor is very irritating, and the taste pungent and persistently acrid. The plant contains a yellowish acrid liquid alkaloid, lobeline, besides lobelic acid, lobelacrin, resin, fixed oil, gum, etc.

Dose. - 1-10 grains (0.065-0.6 Gm.) [7 1/2 grains (5 Gm.), U. S. P.].

Official Preparations

Fluidextractum Lobeliae - Fluidextracti Lobeliae - Fluidextract of Lobelia. - Dose, 1-10 minims (0.06-0.6 Cc.) [8 minims (0.5 Cc), U. S. P.].

Tinctura Lobeliae - Tincturae Lobeliae - Tincture of Lobelia (10 per cent.). - Dose, 8-15 minims (0.5-1.0 Cc.) [15 minims (1 Cc.) as expectorant; 1 fluidram (4 Cc.) as emetic, U. S. P.].

Antagonists and Incompatibles. - The effects of lobelia on the circulatory system are antagonized by the cardiac stimulants. The incompatibles are all caustic alkalies.

Synergists. - The motor depressants and emetics enhance the effect of lobelia.

Physiological Action. - Externally and Locally. - Although the drug is readily absorbed through the skin, there is no action of importance.

Internally. - Digestive System. - Lobelia produces symptoms similar to those of ipecac, save that lobelia is more powerful, occasioning more distressing nausea and. intense prostration.

Circulatory System. - Lobelia is a powerful cardiac depressant, its action being due both to direct depression of the heart and paralysis of the vasomotor centers. Under poisonous doses the heart stops in diastole.

Nervous System. - Full doses depress the motor nerve-ganglia. Poisonous doses are necessary to affect the higher cerebral centers, when coma and convulsions are produced. The muscles and nerves themselves are unaffected by lobelia.

Respiratory System. - The muscular coats of the bronchi are relaxed by the drug. The respiration is slowed even by small doses. Large or toxic doses profoundly depress the respiratory center, death resulting from respiratory failure.

Absorption and Elimination. - The active principle of lobelia is readily absorbed, and is excreted chiefly by the kidneys and skin, the drug acting as a diuretic and diaphoretic. Under emetic doses much of the drug is eliminated by way of the stomach and intestines.

Temperature. - Full doses lower the temperature.

Untoward Action. - Does not differ essentially from the effects of poisoning.

Poisoning. - The symptoms include - violent vomiting and purging, a very weak and irregular pulse, an anxious, livid countenance, skin cold and bathed in perspiration, respiration slow and very feeble, contracted pupils, and possibly coma or convulsions preceding death, which occurs from respiratory failure.

Treatment of Poisoning. - The symptoms should be counteracted by cardiac and respiratory stimulants, employing such drugs as atropine, strychnine, alcohol, ammonia, etc., hypoder-mically.

Therapeutics. - Externally and Locally. - None.

Internally. - While formerly lobelia was used extensively as an emetic, at the present day, owing to the intense nausea and great depression occasioned by the drug, it has been practically supplanted by other less dangerous emetics.

Its principal use nowadays is as a remedy in spasmodic asthma and as an expectorant in certain cases of bronchitis.

Contraindications. - The same as for emetics in general.

Administration. - The powder, fiuidextract, or tincture may be used.