About Herbs

Bottom Line: Current evidence shows that lobelia is not effective for smoking cessation, asthma, or any other medical condition.

The active compound in lobelia is lobeline. Lobeline has a similar activity in the body to nicotine, which explains its common use as an aid in smoking cessation. Like nicotine, lobelia stimulates the central nervous system (CNS), dilates the lung passageways, and increases respiration rate. However, at higher doses, lobelia has the opposite effect and causes CNS depression and reduced breathing rate. In experiments with rats and mice, lobeline increased the release of stimulatory neurotransmitters (dopamine and norepinephrine) from specific parts of the brain, but it is still unclear what significance this has in the human body. Strangely, lobeline can have both additive and antagonistic effects when used at the same time as nicotine.

Not all of lobeline's effects are positive. Many cases of lobeline toxicity have been reported in patients who used high doses or lobelia or used this herb for an extended period of time. For example, when lobeline was experimentally given to healthy volunteers via intravenous injection, the volunteers reported developing a cough, cessation and prolongation of breathing, the feeling of choking, and pressure in the throat and chest.

Quitting smoking:
A systematic review of 16 separate clinical trials was performed to determine the usefulness of lobeline for smoking cessation. All of the clinical trials had flaws in their design, and none followed patients for more than two weeks in order to evaluate the long-term safety and effectiveness of lobeline. The reviewers concluded that no evidence supports the hypothesis that lobelia is effective for smoking cessation.

Lobella, asthma weed, eyebright, gagroot, Indian pink, Indian tobacco, pukeweed, vomit weed, Lobelia berlandieri, Lobelia cardinalis

Derived from the aerial parts of the plant. Patients use this supplement for smoking cessation and to treat asthma and depression. The piperidine alkaloids (e.g. lobeline) are thought responsible for the activity of this botanical. Animal and in vitro studies show that lobeline crosses the blood-brain barrier, has similar activity to nicotine, and stimulates the release of dopamine and norepinephrine ⁽⁵⁾. At low doses lobelia has stimulant effects, but higher doses result in CNS depression. Significant toxicity has occurred following use including vomiting, seizures, cardiovascular collapse, and coma ⁽²⁾. Lobelia may have additive toxicity when combined with nicotine ⁽¹²⁾. Clinical studies evaluating lobelia for smoking cessation do not support its use ⁽¹⁵⁾. Patients should be warned not to use this supplement.

Animal studies report that lobeline has anxiolytic and cardiovascular effects and increases cognitive performance. Lobelia has central stimulant activity, dilates bronchioles, and increases respiration rate at low doses, but higher doses cause CNS and respiratory depression ⁽¹⁰⁾. In rat and mouse models lobeline increases dopamine release from striatal synaptosomes, increases norepinephrine release from the hippocampus ⁽⁵⁾, and binds extensively to nicotinic receptors both centrally and peripherally ⁽⁴⁾. In vitro, lobeline redistributes dopamine pools in presynaptic vesicles and antagonizes their release following amphetamine stimulation. Lobeline can have both antagonistic and synergistic effects when combined with nicotine and does not induce receptor up-regulation as seen with nicotine ⁽¹⁰⁾. Intravenous administration of approximately 12 mcg/kg lobeline to healthy human subjects resulted in cough, apnea, prolonged inspiration and expiratory pause, the feeling of choking, and pressure in the throat and chest ⁽⁹⁾. Animal studies suggest that beta-amyrin palmitate stimulates the release of norepinephrine in the brain, possibly leading to an antidepressant effect ⁽¹⁾.

Lobeline, an extract from Lobelia inflata, has high lipophilicity, crosses the blood brain barrier, and distributes widely throughout the body. Additional pharmacokinetic data is not available.
⁽¹¹⁾

Lobelia is known to cross into breast milk and should not be consumed by pregnant or nursing mothers.

Reported: Nausea, vomiting, sweating, cough, dizziness, bradycardia, hypertension, seizures, respiratory stimulation (low doses) or depression (high doses).
Toxicity: Sinus arrhythmia, bundle branch block, diaphoresis, cardiovascular collapse, seizures, coma.
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Nicotine: Lobelia may have additive effects when combined with nicotine-containing products, resulting in toxicity.
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Stead LF, Hughes JR. Lobeline for smoking cessation. Cochrane Database Syst Rev 2002;(2):CD000124.
Although 16 studies have been performed evaluating lobelia for smoking cessation, none met inclusion criteria set by Stead and Hughes. Trials evaluated only short-term efficacy (up to 14 days) of lobelia use with no long-term follow-up performed. Reduction in number of cigarettes, not abstinence, was the primary outcome for a majority of the studies reviewed. No evidence supports the hypothesis that lobelia is effective for smoking cessation.