Poisoning Associated with Consumption of a Homemade Medicinal…

Discussion

This investigation provides compelling evidence that this mass intoxication was caused by homemade medicinal liquor containing Aconitum alkaloids. Aconitum lycoctonum is included in the Aconitum genus of >250 species of flowering plants belonging to the Ranunculaceae family. These herbaceous perennial plants are native to the mountainous parts of the Northern Hemisphere, growing in the moisture-retentive but well-draining soils of mountain meadows, mainly in southwestern China. Among medicinal herbs, Aconitum species are unique: while reportedly considered a beneficial herb root used historically and extensively for medicinal purposes in China, Aconitum species, also known as wolfbane, are highly toxic, and if not prepared correctly, consumption can be rapidly fatal.

Aconite tubers and roots are traditionally used in medications to treat pain and a range of diverse ailments, including diarrhea, edema, asthma, various tumors, rheumatism, rheumatoid arthritis, and other inflammatory disorders (2,3). They are frequently used in traditional Chinese medicine, and, although the sale of unprocessed Aconitum species is prohibited, they can be illicitly acquired in open markets in China, especially in Yunnan and Guizhou provinces. These sales of unprocessed roots occur, even though the activity is forbidden by drug safety regulation stipulated by the State Administration for Market Regulation, and even though the pharmaceutical use of drugs containing Aconitum alkaloids is strictly monitored in China.

The medicinal use of Aconitum species requires strict adherence to processing and cooking guidance, which is based on the prescribed dosage (4). Only licensed manufacturers or authorized practitioners are allowed to prepare Aconitum species for medical use. Traditional Chinese methods for processing herbs (páo zhì), including heating, soaking, and boiling for several hours, are reported to enhance the properties or reduce or eliminate toxicity, and in the case of Aconitum species, convert the alkaloids to comparatively less toxic or nontoxic derivatives (5), so that medicinal liquors containing aconite roots may be safely drunk for health promotion (3). If the products are misused or not prepared correctly, aconite ingestion can result in rapid death. Aconite roots and leaves, as well as honey made from aconite nectar, are all highly toxic. If they are not properly decocted for oral consumption, Aconitum plant products can be safely used only when applied topically. As little as 0.2 mg (200 μg) of Aconitum alkaloids can cause poisoning, and 2.0 mg (2,000 μg) is sufficient to result in death.

Although the risk of aconite toxicity is known, in some areas of China, Aconitum plant products are still sought for their purported health benefits. Approximately 5,000 cases of aconite poisoning were reported in China, Germany, Japan, and other countries during 1993–2005; most cases of fatal poisoning occurred in China (1). Aconite roots contain various chemical constituents, such as aconitine, mesaconitine, and bullatine A, which have significant pharmacologic activity and are also toxic. The Aconitum alkaloids primarily affect the central nervous system, heart, and muscle cells (6–8), with cardiac damage the most serious consequence. As was the case with most of the victims of this intoxication, severe cases of cardiac toxicity from consumption of aconitine-containing herbal preparations typically manifest clinically as ventricular tachycardia and fibrillation, frequently resulting in death. Aconitum alkaloids bind to cardiac muscle cell receptors that regulate sodium-ion channels, preventing repolarization of cells, and resulting in paralysis and death (9,10).

The findings in this report are subject to at least three limitations. First, no toxicology testing was done on the victims. However, the hypothesis that the toxicant was a homemade medicinal liquor containing products from Aconitum species is supported by the fact that 100% of persons who drank it and none of those who did not drink it became ill. Second, it was not possible to ascertain the precise volume of medicinal liquor consumed by each person, but the amount consumed by each person ranged from 5–125 mL (approximately 1–25 tsp). On the basis of the concentration of residue identified by toxicology testing (81.9 μg/mL), it can be inferred that as little as 25 mL (approximately 5 tsp) contained sufficient Aconitum alkaloids to be lethal. Finally, the source of Aconitum species could not be ascertained. In a retrospective analysis of case reports of aconite poisoning in China during 2004–2015, the most commonly reported route of exposure was drinking medicinal liquors containing Aconitum alkaloids; concurrent ethanol ingestion could rapidly increase the absorption of Aconitum alkaloids into the blood (3), which might have contributed to the rapid onset and five fatal cases in persons who drank only the medicinal liquor in this event. In addition, the absence of labeling of the root might have contributed to its mistaken inclusion in the recipe.

Although Aconitum species can be used medicinally if properly prepared by a licensed manufacturer or authorized practitioner, ingestion can also result in fatal intoxication; therefore, regulations and public health messaging to increase awareness of the toxicity of Aconitum species can help prevent inadvertent aconite poisoning. Emphasizing the danger of drinking medicinal liquors containing Aconitum alkaloids and the identification of plants that are easily confused are critical to ensure the safe use of Aconitum species. Conspicuous labeling of bottles containing homemade brews might prevent misuse, especially oral consumption of products that are only appropriate for topical use. In addition, existing safety monitoring of materials containing Aconitum alkaloids and surveillance of the poison control network are critical.