Lobelia: is lobelia toxic?
by Paul Bergner
Medical Herbalism 10(1-2):1,15
Lobelia inflata was one of the most-often prescribed medicinal herbs both in North America and in Great Britain during the nineteenth century. It was used by all schools of medicine, but by none more so than the Thomsonian herbalists in North America, the Coffinites in Britain, and by their physician successors of the Physiomedicalist school. During the warfare between the medical sects in that century, lobelia became a symbol. To the herbalists it was a harmless herb, one of their greatest healers, and their best alternative to the extensive bloodletting and administration of mercury-derived medicines that then dominated standard medicine. To their competitors of the Regular school of medicine, lobelia was a deadly poison. The latter claim was used to justify licensing laws and in some states laws to forbid the use of lobelia or even giving it to another. Unsubstantiated and unreferenced claims of lobelia toxicity entered the medical literature of the Regulars in 1810, on the basis of selective testimony in the trial of Samuel Thomson for allegedly causing the death of Ezra Lovett the year before. Those claims have been copied and cited uncritically ever since, and remain in segments of the medical literature today as proof of prejudice and poor scholarship by their authors. In this issue, we attempt to tell the whole story, from its beginning through the present day. Our series of articles includes a literature review on lobelia toxicity, from 1809 to the present, which follows below. We also cover the trial of Samuel Thomson and the conflicting accounts of the death of Ezra Lovett, which remains the only case of alleged lobelia toxicity to provide details of dose, treatment, and symptoms, and we attempt to ascertain the cause of his death in the light of modern medical knowledge. We also cover a brief flurry of lobelia toxicity allegations in London during the early 1850s. The series of articles, although covering historical and legal subjects, contains much information about the clinical use of lobelia and about social divisions and prejudices in medical care which persist today.
Lobelia toxicity: A literature review
by Paul Bergner
Medical Herbalism 10(1-2);15-26
Lobelia inflata was introduced into medical usage in North America by the herbalist Samuel Thomson in the early nineteenth century. Subsequently, Thomson and millions of medical professionals, lay herbalists, and patients who later followed his medical theories, used lobelia freely as an emetic, antispasmodic, asthma treatment, and childbirth aid without regard for potential toxicity (Griggs, Thomson 1831; Colby; Cook). Thompsonian practitioners and their patients viewed Thomsonian herbalism as an alternative to conventional medicine of the day, which employed bloodletting and poisonous mercury preparations as its chief methods. by 1840, perhaps one-fifth of the population of the United States used Thomsonian herbalism, including the unrestricted use of lobelia, as their primary care medicine (Thomson; Griggs). The movement crossed the Atlantic to England during the late 1830s, spread among the working classes, and gave birth there to the profession of “medical botanist.” Lobelia is still in use in that country today by medical herbalists. The Thomsonian movement declined among the public in both North America and England by the 1860s, probably in response to the abandonment of bloodletting and mercurials by conventional medicine (Griggs). The use of lobelia survived among some branches of the medical profession. At least one medical school in the United States (The Physiomedicalist Institute in Chicago) taught the use of lobelia in unrestricted doses without regard for toxicity as recently as 1910. Lobelia was listed as an official medicine — as a treatment for asthma — in the first United States Pharmacopoeia in 1820, and remained official in the U.S.P. until 1920. Medical doctors of the Eclectic school used it as an antispasmodic emetic and childbirth aid at least through the 1940s.The plant’s medicinal action and potential toxicity is attributed to its content of the alkaloid lobeline, present at between 0.26 and 0.40 % in the plant. Lobeline hydrochloride was used as an emergency respiratory stimulant in intravenous, intramuscular, and subcutaneous doses by conventional physicians in the U.S. beginning in 1938 (Osol and Farrar). This use was still listed in pharmacology texts as recently as 1971 (Gisvold and Doerge). Lobeline sulfate for oral use was sold without prescription in the U.S. as recently as 1990 as a smoking deterrent (Anonymous, 1990)).
Literature on lobelia toxicity is curiously split, with standard toxicology references failing to mention it, but the textbooks of conventional medicine asserting that lobelia and/or lobeline are potentially deadly poisons. Neither is mentioned at all in the encyclopedic ten-volume Comprehensive Toxicology (Sipes et al. 1997), or in such standard works on plant toxicology as Harbourne and Baxter’s Plant Toxicology, or Toxicology of Plant and Fungal Compounds by Keeler and Tu. Table 1 shows a listing of standard references in plant safety, pharmacology, or toxicology which either fail to mention lobelia and lobeline at all, or which describe them but make no mention of potential toxicity beyond lobelia’s emetic properties. The author was unable to find any listing of toxicity for lobelia in the toxicology section of the science library at University of Colorado in Boulder in a search during the summer of 1998.