Lobelia inflata                          Common name:  Indian tobacco
Family: Campanulaceae

Part used:  Aerial parts

Constituents:  Piperidine alkaloids (lobeline, isolobeline and others), Chelidonic acid, Resins, Gums, Fats

Medicinal actions:  Respiratory stimulant, expectorant, emetic, diaphoretic, anti-spasmodic, nervine.

Medicinal use: Lobelia is used primarily for its relaxant effects in the bronchioles.  Its ability to relax the smooth muscle of the bronchioles make it an invaluable part of an acute or chronic asthma formula. Lobelia reduces smooth muscle spasm and thus lowers arterial pressure and vascular tension. Is also a useful aid in smoking withdrawal.

Pharmacology: 

• Piperidine alkaloids (lobeline) shares a structural similarity with nicotine, and thus binds to nicotinic acid receptors and exerts many of the same effects to a lesser degree (is 1/20 -1/5 as potent as nicotine).
• The alkaloids in Lobelia exert paradoxical effects. Lobeline is a powerful respiratory stimulant by stimulating the respiratory centers and exerts this effect even in relatively small doses. Isolobeline is an emetic and respiratory relaxant (relaxes smooth muscle) that most powerfully exerts its action at higher doses. The combined action of both of these alkaloids makes Lobelia a stimulating relaxant.  The net effect in the lungs will be a promotion of mucous secretion, expectoration and a reduction in bronchial spasm.

Pharmacy: Infusion:  1/4-1/2 tsp dried leaves/ cup water; 1 cup TID. Tincture (1:5, 60%) fresh or (1:8, 60%) dried, 0.5 ml TID.

Toxicity: Burning esophagus, salivation, N/V, weakness, stupor, tremors, paralysis, tachypnea, hypothermia, rapid pulse, pinpoint pupils, unconsciousness, convulsions, coma, exhaustion, sweating, prostration, miosis, death. The toxic dose is variable and some individuals are sensitive to the therapeutic dose with vomiting.

Contraindications: In general relaxation and dyspnea (especially when due to a weakened heart or valvular incompetence),  in nervous prostration, shock or paralysis; heart disease (including cardiomegaly, fatty heart, pericarditis with effusion, valvular incompetence, cardiac decompensation, sinus arrhythmia or bundle branch block), pneumonia or pleural effusion, hypertension, low vitality, pregnancy or tobacco sensitivity.