II. Background
- Poison Hemlock is a group of Poisonous Plants in the cicuta or conium genus
- Unrelated to the coniferous hemlock tree (which is not poisonous)
- Historically, Socrates was poisoned with hemlock
- Poison Hemlock (Conium Maculatum) may be found as a non-native weed throughout the U.S.
- White flowers and hollow stem
- Growth height up to 5 feet
- Similar appearance to wild carrot or wild celery
- All parts of hemlock plant are poisonous
III. Mechanism: Toxicity
- Hemlocks contain a group of nicotinic, piperidine alkaloids including Coniine, which act at Nicotinic Acetylcholine Receptors
- Early, alkaloids are Agonists at Nicotinic Acetylcholine Receptors
- Later, alkaloids are antagoinsts at Nicotinic Acetylcholine Receptors (resulting in paralysis)
IV. Pharmacokinetics
- Coniine is rapidly absorbed after ingestion
- Toxic ingestion level (6 to 8 leaves): >150 mg Coniine
V. Signs
- Ocular (early)
-
Lung
- Early: Bronchoconstriction and bronchorrhea
- Later: Respiratory paralysis
- Cardiac
- Early: Tachycardia and Hypotension
- Later: Bradycardia
- Gastrointestinal (early)
- Neurologic (later)
- Ascending flaccid Muscle paralysis
- CNS Depression
- Seizures
- Myalgias
- Rhabdomyolysis
VI. Labs
- See Unknown Ingestion
- Basic chemistry panel (chem8)
- Creatine Phosphokinase (CPK)
- Coniine
- Although serum and urine levels may be obtained, they are not typically useful in clinical decision making
VII. Management
-
ABC Management
- Advanced Airway and Mechanical Ventilation may be needed
- Supportive Care
- Seizures
- Hemodynamic instability and Hypotension
- Vasopressors as needed if refractory to Intravenous Fluids
-
Rhabdomyolysis
- See Rhabdomyolysis
- Hemodialysis is not effective
- Disposition
- Improving or asymptomatic patients may be discharged at 6 hours after ingestion
VIII. Complications
- Respiratory Failure (may be lethal without intervention)
- Rhabdomyolysis
IX. References
- Tomaszewski (2023) Crit Dec Emerg Med 37(9): 32
- Vetter (2004) Food Chem Toxicol 42(9):1373-82 +PMID: 15234067 [PubMed]
- Konca (2016) Turk J Emerg Med 14(1):34-6 +PMID: 27331163 [PubMed]
Images: Related links to external sites (from Bing)
Related Studies
| Concepts | Pharmacologic Substance (T121) , Biologically Active Substance (T123) , Organic Chemical (T109) |
| MSH | C007112 |
| SnomedCT | 34792002 |
| English | cicutine, conicine, coniine, D-2-(n-propyl)piperidine, koniin, Conicine, Cicutine, (2S)-2-Propylpiperidine, Coniinum, CONIINE, Coniine, Coniine (substance) |
| Spanish | coniína (sustancia), coniína |
Ontology: Conium maculatum (C0242871)
| Definition (MSH) | Conium maculatum is a large toxic umbelliferous plant, which contains the alkaloid coniine which affects the nervous system. The dried, fully grown, unripe fruit has sedative, anodyne, and antispasmodic effects. |
| Concepts | Plant (T002) |
| MSH | D029982 |
| SnomedCT | 26706004 |
| English | Conium maculatum, Conium maculatums, maculatum, Conium, maculatums, Conium, hemlock poisoning, poison hemlock, hemlock poison, conium maculatum, Conium maculatum L., fool's-parsley, spotted hemlock, Poison hemlock, Conium maculatum (organism) |
| Czech | Conium maculatum |
| Portuguese | Conium maculatum |
| Spanish | Conium maculatum, Cicuta maculatum (organismo), Cicuta maculatum, cicuta venenosa |
| German | Conium maculatum |
| French | Cigüe tachetée, Cigüe tachée, Grande ciguë, Grande cigüe, Conium maculatum, Ciguë tachée |
| Italian | Conium maculatum |
| Norwegian | Conium maculatum, Skarntyde, Giftkjeks |
| Dutch | Conium maculatum |
Ontology: Hemlock (C0242872)
| Definition (MSH) | Any of several poisonous plants, commonly called poison hemlock, of the CICUTA or CONIUM genus. The hemlock tree (TSUGA) is completely unrelated being a coniferous tree of the pine family. |
| Concepts | Plant (T002) |
| MSH | D018652 |
| SnomedCT | 261299000 |
| English | Hemlock, Hemlocks, hemlock, Hemlock (organism) |
| Swedish | Odört |
| Czech | Cicuta, Conium - jedovaté rostliny |
| Finnish | Katko |
| Russian | BOLIGOLOV KRAPCHATYI, BOLIGOLOV PIATNISTYI, БОЛИГОЛОВ КРАПЧАТЫЙ, БОЛИГОЛОВ ПЯТНИСТЫЙ |
| Italian | Cicute |
| Polish | Tsuga |
| Norwegian | Hemlock |
| Spanish | abeto común (organismo), abeto común, Cicutas |
| French | Ciguë |
| German | Schierling |
| Dutch | Gevlekte scheerling, Scheerling, Waterscheerling |
| Portuguese | Cicutas |
Ontology: Conium maculatum poisoning (C0275228)
| Concepts | Injury or Poisoning (T037) |
| SnomedCT | 68935009 |
| English | Conium maculatum poisoning, Poison hemlock poisoning, Conium maculatum poisoning (disorder) |
| Spanish | intoxicación por Cicuta maculatum (trastorno), intoxicación por Cicuta maculatum, intoxicación por veneno de cicuta |
