Close
New

Medscape is available in 5 Language Editions – Choose your Edition here.

 

Hemlock Poisoning Medication

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

Medication Summary

Do not use ipecac during gastric decontamination because of risk of inducing seizures. Other agents, if indicated, can be used.

Next

GI Decontaminants

Class Summary

Used to limit amount of adsorbed toxin.

Activated charcoal (Liqui-Char)

 

Emergency treatment in poisoning caused by drugs and chemicals. Network of pores present in activated charcoal adsorbs 100-1000 mg of drug per gram of charcoal. Does not dissolve in water.

For maximum effect, administer within 30 min after ingesting poison.

Previous
Next

Antiemetics

Class Summary

Useful in treatment of symptomatic nausea. Consider risks or benefits of increased sedation and possibility of lowering seizure threshold.

Ondansetron (Zofran)

 

Selective 5-HT3-receptor antagonist that blocks serotonin both peripherally and centrally.

Metoclopramide (Reglan)

 

Works as antiemetic by blocking dopamine receptors in the chemoreceptor trigger zone of CNS.

Previous
Next

Benzodiazepines

Class Summary

Can be used to control/prevent seizures and may decrease agitation. Rapid onset of action is advantageous, as is their improved safety profile vs barbiturates.

Diazepam (Valium)

 

Depresses all levels of CNS (eg, limbic and reticular formation), possibly by increasing activity of GABA.

Lorazepam (Ativan)

 

Sedative hypnotic with short onset of effects and relatively long half-life.

Increasing action of GABA, which is a major inhibitory neurotransmitter in the brain, may depress all levels of CNS, including limbic and reticular formation.

Monitoring patient's blood pressure after administering dose is important. Adjust prn.

Lorazepam contains benzyl alcohol, which may be toxic to infants in high doses.

Midazolam (Versed)

 

Used as alternative in termination of refractory status epilepticus. Because water soluble, takes approximately three times longer than diazepam to peak EEG effects. Thus, the clinician must wait 2-3 min to fully evaluate sedative effects before initiating procedure or repeating dose. Has twice the affinity for benzodiazepine receptors than diazepam. May be administered IM if unable to obtain vascular access.

Previous
Next

Barbiturates

Class Summary

Can be used to control/prevent seizures and may decrease agitation. Rapid onset of action is advantageous.

Pentobarbital (Nembutal)

 

Short-acting barbiturate with sedative, hypnotic, and anticonvulsant properties and can produce all levels of CNS mood alteration.

Phenobarbital (Barbita, Luminal, Solfoton)

 

Can be administered orally; in status epilepticus, it is important to achieve therapeutic levels as quickly as possible. IV dose may require approximately 15 min to attain peak levels in the brain. If injected continuously until convulsions stop, brain concentrations may continue to rise and can exceed that required to control seizures. Important to use minimal amount required and wait for anticonvulsant effect to develop before giving a second dose.

If IM route chosen, administer into areas with little risk of encountering a nerve trunk or major artery such as one of large muscles like gluteus maximus, vastus lateralis, or other. Permanent neurological deficit may result from injecting into or near peripheral nerves.

Restrict IV use to conditions in which other routes are not possible, either because patient is unconscious or because prompt action is required.

Previous
Next

General anesthetics

Class Summary

Can be used to control seizures.

Propofol (Diprivan)

 

Phenolic compound unrelated to other types of anticonvulsants. Has general anesthetic properties when administered IV.

Previous
 
 
Contributor Information and Disclosures
Author

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.

Acknowledgements

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.

References
  1. Mowry JB, Spyker DA, Cantilena LR Jr, McMillan N, Ford M. 2013 Annual Report of the American Association of Poison Control Centers' National Poison Data System (NPDS): 31st Annual Report. Clin Toxicol (Phila). 2014 Dec. 52(10):1032-283. [Medline]. [Full Text].

  2. Schep LJ, Slaughter RJ, Becket G, Beasley DM. Poisoning due to water hemlock. Clin Toxicol (Phila). 2009 Apr. 47(4):270-8. [Medline].

  3. Uwai K, Ohashi K, Takaya Y. Exploring the structural basis of neurotoxicity in C(17)-polyacetylenes isolated from water hemlock. J Med Chem. 2000 Nov 16. 43(23):4508-15. [Medline].

  4. Furbee B, Wermuth M. Life-threatening plant poisoning. Crit Care Clin. 1997 Oct. 13(4):849-88. [Medline].

  5. Goldfrank LR, Flomenbaum NE, Lewin NA, et al, eds. Goldfrank's Toxicologic Emergencies. 6th ed. Appleton & Lange; 1998. 2, 318, 338, 1246, 1252-3.

  6. Hopkins J. The glycoalkaloids: naturally of interest (but a hot potato?). Food Chem Toxicol. 1995 Apr. 33(4):323-8. [Medline].

  7. Krenzelok EP, Jacobsen TD. Plant exposures ... a national profile of the most common plant genera. Vet Hum Toxicol. 1997 Aug. 39(4):248-9. [Medline].

  8. Lopez TA, Cid MS, Bianchini ML. Biochemistry of hemlock (Conium maculatum L.) alkaloids and their acute and chronic toxicity in livestock. A review. Toxicon. 1999 Jun. 37(6):841-65. [Medline].

  9. Olson KR. Hemlock. Poisoning and Drug Overdose. 3rd ed. Appleton & Lange; 1999. 22, 25, 30, 265-74.

  10. Panter KE, James LF, Gardner DR. Lupines, poison-hemlock and Nicotiana spp: toxicity and teratogenicity in livestock. J Nat Toxins. 1999 Feb. 8(1):117-34. [Medline].

  11. Reynolds T. Hemlock alkaloids from Socrates to poison aloes. Phytochemistry. 2005. 66(12):1399-1406. [Medline].

  12. Vetter J. Poison hemlock (Conium maculatum L.). Food Chem Toxicol. 2004 Sep. 42(9):1373-82. [Medline].

  13. Watson WA, Litovitz TL, Rodgers GC, et al. 2002 annual report of the American Association of Poison Control Centers Toxic Exposure Surveillance System. Am J Emerg Med. 2003 Sep. 21(5):353-421. [Medline].

 
Previous
Next
 
Hemlock. Photo by Cornell University Poisonous Plants Informational Database
 
 
 
All material on this website is protected by copyright, Copyright © 1994-2016 by WebMD LLC. This website also contains material copyrighted by 3rd parties.