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Hemlock Poisoning Treatment & Management

  • Author: Daniel E Brooks, MD; Chief Editor: Asim Tarabar, MD  more...
Updated: Apr 21, 2015

Prehospital Care

For patients with possible hemlock poisoning, maintain the airway, obtain IV access airway, and assist with ventilation as needed.


Emergency Department Care

Rapidly assess and correct any life-threatening conditions. Since no antidote exists for either toxin, GI decontamination (if appropriate) and aggressive supportive care are mainstays of treatment for hemlock poisoning. Schep et al provide a concise review of water hemlock poisoning and management.[2]

  • Secure airway.
  • Decontaminate GI tract if timing is appropriate.
    • If no contraindications exist, gastric lavage may be of limited benefit if performed rapidly after the ingestion.
    • Administer activated charcoal if the patient is able to protect the airway and presents within 1 hour of ingestion. Ipecac should not be used.
    • Caution should be exercised in patients exposed to water hemlock because they are at increased risk of having seizures, and can eventually aspirate the charcoal.
  • Treat seizures with benzodiazepines; use barbiturates if needed.
    • Provide prophylaxis with water hemlock ingestion.
    • Benzodiazepines and barbiturates help control agitation and raise the seizure threshold.
  • Aggressively administer IV fluids for dehydration or rhabdomyolysis.
    • Replete volume if signs of hypovolemia or hypotension are present.
    • Correct electrolyte abnormalities.
    • Administer fluids with sodium bicarbonate for urinary alkalinization if evidence of rhabdomyolysis exists. If using sodium bicarbonate, mixing it in 5% dextrose in water (D5W) is important to limit the amount of sodium load.
  • Potassium levels should be monitored and corrected as needed.
  • Administer antiemetics. Many antiemetics may lower the seizure threshold and should be used cautiously.
  • Provide ventilatory support, if necessary.


A regional poison center or a medical toxicologist can assist with patient treatment and potentially with plant identification. The regional poison control center should be contacted (800-222-1222) to discuss optimal management of all known or suspected hemlock poisonings.

Contributor Information and Disclosures

Daniel E Brooks, MD Co-Medical Director, Banner Good Samaritan Poison and Drug Information Center, Department of Medical Toxicology, Banner Good Samaritan Medical Center

Daniel E Brooks, MD is a member of the following medical societies: American Academy of Clinical Toxicology, American College of Emergency Physicians, American College of Medical Toxicology

Disclosure: Nothing to disclose.

Specialty Editor Board

John T VanDeVoort, PharmD Regional Director of Pharmacy, Sacred Heart and St Joseph's Hospitals

John T VanDeVoort, PharmD is a member of the following medical societies: American Society of Health-System Pharmacists

Disclosure: Nothing to disclose.

Chief Editor

Asim Tarabar, MD Assistant Professor, Director, Medical Toxicology, Department of Emergency Medicine, Yale University School of Medicine; Consulting Staff, Department of Emergency Medicine, Yale-New Haven Hospital

Disclosure: Nothing to disclose.

Additional Contributors

David A Peak, MD Associate Residency Director of Harvard Affiliated Emergency Medicine Residency; Attending Physician, Massachusetts General Hospital; Assistant Professor, Harvard Medical School

David A Peak, MD is a member of the following medical societies: American College of Emergency Physicians, Society for Academic Emergency Medicine, Undersea and Hyperbaric Medical Society, American Medical Association

Disclosure: Partner received salary from Pfizer for employment.


Michael Hodgman, MD Assistant Clinical Professor of Medicine, Department of Emergency Medicine, Bassett Healthcare

Michael Hodgman, MD is a member of the following medical societies: American College of Medical Toxicology, American College of Physicians, Medical Society of the State of New York, and Wilderness Medical Society

Disclosure: Nothing to disclose.

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Hemlock. Photo by Cornell University Poisonous Plants Informational Database
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