Jimsonweed

Jimsonweed (also known as thorn apple and devil's trumpet) is part of a genus of distinctive nightshades that were imparted greater infamy by the memetic power of the internet. Towards autumn, it develops a semi-eponymous spiny seed pod.

All parts of Datura contain numerous tropane alkaloids including atropine and scopolamine, although the composition ratio and overall quantity vary with maturity of the plant, as well as in a wide range between individual plants. Both of these chemicals are competitive muscarinic receptor antagonists, although scopolamine is superior in its ability to cross the blood-brain barrier.

Presentation:

The combination of ingested atropine and scopolamine leads patients to typically present with a classic anticholinergic toxidrome — "mad as a hatter" (altered mental status), "blind as a bat" (mydriasis), "red as a beet" (plethora), "hot as a hare" (hyperthermia, anhidrosis), and "dry as a bone" (xerostomia, urinary retention). Tachycardia may also be seen due to M2 receptor blockade.

Death resulting directly from anticholinergic activity is rare when treatment is available; otherwise, death is usually due to downstream factors such as exposure or foul play.

Management:

Decontamination is recommended even with delayed arrival to the ED, as anticholinergics also reduce bowel motility. Whole-bowel irrigation may be helpful in the setting of seed ingestion; otherwise, activated charcoal is the standby.

Treatment is initially supportive — reassurance for agitation and hallucination, cooling for hyperthermia, and catheterization for urinary retention. If the patient is severely agitated, a benzodiazepine may also be administered.

If severe and/or refractory, the anticholinergic toxidrome can be reversed with physostigmine, a cholinesterase inhibitor with central nervous system activity, at a slow push (0.5 - 2.0 mg at <1 mg/min) with repeat dosing if necessary. The patient must be carefully monitored as physostigmine may also precipitate a cholinergic toxidrome.

Note that your institution may require that administration of physostigmine be supervised by a toxicologist or the Poison Control center; or that your institution might not carry physostigmine anymore. In addition, there has been a supply chain breakdown that has limited the supply of physostigmine in the US, with no projected resolution date. A case presented in May 2021 used rivastigmine to successfully manage anticholinergic syndrome due to diphenhydramine overdose, and suggested that this drug may offer a stopgap solution.