Lobelia

Scientific Name(s): Lobelia inflata L.
Common Name(s): Herba Lobellae Chinensis, Asthma weed, Bladderpod, Chinese Lobelia , Eyebright, Gagroot, Indian tobacco, Indian weed, Pukeweed, Vomitwort

Medically reviewed by Drugs.com. Last updated on Apr 21, 2022.

Clinical Overview

Use

L. inflata and its major alkaloid, lobeline, have been used in smoking cessation programs and have been proposed for treatment of other drug dependencies; however, clinical evidence is limited.

Dosing

There is no recent clinical evidence to support the use of lobelia. The sale of OTC lobeline products for smoking cessation was prohibited by the US Food and Drug Administration (FDA) in 1993.

Traditional use of the leaf (eg, as an expectorant) suggests 100 mg of dry herb up to 3 times a day. However, there are no clinical trials to support this use. Doses of 0.6 to 1 g leaf are considered toxic, while 4 g of leaf is considered to be fatal.

Contraindications

Contraindications have not been defined; however, the sale of lobelia OTC products for smoking cessation is prohibited by the FDA due to a lack of efficacy and safety evidence.

Pregnancy/Lactation

Avoid use. Documented adverse effects, including loss of uterine tone and lack of safety evidence.

Interactions

None well documented.

Adverse Reactions

Lobelia and lobeline are capable of inducing nausea, vomiting, tremors, and dizziness at high doses. Lobelia alkaloids are cardioactive, and cardiotoxicities, including hypotension, tachycardia, and convulsion, have been reported. Contact dermatitis has also been reported.

Toxicology

Toxic dosages of the plant have been described: 1 g of leaf is toxic, while 4 g of leaf is considered to be a fatal dose. The alkaloid lobeline was not genotoxic or mutagenic in 1 study, and liver and kidney biochemistry in mice appeared unaffected.

Scientific Family

• Campanulaceae (harebell)

Botany

L. inflata is a branching, perennial herb that is completely self-fertilizing and reproduces only once in its lifetime.1 It grows from 0.3 to 0.9 m tall and produces small, violet-pinkish flowers in the alternate leaf axils. The base of the flower expands to form the seed capsule, which is the source of the name "inflata." It is native to the eastern half of United States and parts of Canada.2, 3 The genus Lobelia has more than 400 recognized species, some of which contain alkaloids similar to those of L. inflata, including Livistona chinensis, a plant important in traditional Chinese medicine.3

History

The plant was named in honor of Matthias de Lobel, a 16th century Flemish physician and botanist, and is native to North America. American Indians smoked the leaves like tobacco and used them medicinally for respiratory ailments. Lobelia was introduced into New England medical practice in the 18th century to produce emesis. It was also used in treating colic, rheumatism, fever, and asthma. By the 19th century, lobelia was considered an important medicinal plant used in many conditions (eg, abscess, insomnia, tetanus, shock); however, fatalities were recorded due to dosing inconsistencies.4, 5 In 1993, the sale of lobelia OTC products for smoking cessation was prohibited by the FDA.3, 6, 7

Chemistry

The piperidine alkaloid lobeline was isolated as the main active component of Lobelia in 1921,8 and its absolute stereochemistry was deter...