eMedicine Specialties > Emergency Medicine > Toxicology

Toxicity, Valproate: Follow-up

Author: Timothy Wiegand, MD, Clinical Assistant Professor of Medicine, University of Vermont College of Medicine and Maine Medical Center; Associate Medical Director, Northern New England Poison Center
Coauthor(s): Kent R Olson, MD, FACEP, Clinical Professor of Medicine and Pharmacy, University of California San Francisco; Medical Director, San Francisco Division, California Poison Control System; Herbert E Hern Jr, MD, Assistant Clinical Professor, Department of Emergency Medicine, University of California, San Francisco; Residency Director, Department of Emergency Medicine, Highland General Hospital
Contributor Information and Disclosures

Updated: Jan 26, 2009

Follow-up

Further Inpatient Care

  • Depending on level of toxicity, patients with valproic acid overdose usually require admission to the intensive care unit (ICU) for continuous monitoring.
    • Their condition may progressively deteriorate as valproic acid is absorbed and moves from the intravascular compartment to the CNS compartment.
    • Intestinal absorption after overdose may be delayed several hours.
  • Patients with overdose must be evaluated from a psychiatric point of view for plan of suicide or grave disability.

Further Outpatient Care

  • After the patient's condition is stabilized and he or she is discharged, an ongoing relationship between the patient and a mental health professional is recommended if the overdose was intentional.

Transfer

  • After patients are medically cleared, they may be transferred to a psychiatric facility. However, this disposition highly depends on the patient's symptoms and the amount of ingestion.
  • In one multicenter case series of 134 patients with valproic acid ingestions (80 with toxic VPA levels at admission), the mean hospital stay for all patients was 44.7 hours (standard deviation, 28 h).4

Complications

  • Valproic acid is used in the treatment of mood disorders in addition to its use as an antiseizure medication. Emergency personnel must consider the possibility of multidrug overdoses and availability of other antiseizure medications, including sedative-hypnotics, lithium, and other medications used to treat mood disorders.
  • Patients must be monitored for signs and symptoms of other toxic syndromes.
  • Obtain acetaminophen levels to rule out ingestion of this substance (see Laboratory Studies).

Prognosis

  • The prognosis depends on the amount ingested, the decontamination and elimination strategies administered (if indicated), and the supportive care given.
  • Severe ingestions may resolve without sequelae after aggressive decontamination, elimination, and adequate supportive care.
  • L-carnitine is reportedly helpful in valproic acid overdose associated with hyperammonemia, hepatotoxicity, and coma. However, its role remains to be confirmed. Some authors recommend its empiric use in overdoses when levels are greater than 450 mg/L.
  • The optimum dose, frequency, and route of administration (oral or intravenous) remain to be determined.

Patient Education

Miscellaneous

Medicolegal Pitfalls

  • Failure to diagnose a concomitant ingestion or underlying medical condition that results in serious morbidity
  • Failure to obtain serial serum valproic acid levels, especially after ingestion of extended-release formulations
  • Failure to aggressively decontaminate GI tract with whole-bowel irrigation after exposure to the extended-release formulation
 
Acknowledgments

The staff, faculty, and fellows of the San Francisco Bay Area Regional Poison Control Center contributed insight, review, and encouragement for this review.



More on Toxicity, Valproate

Overview: Toxicity, Valproate
Differential Diagnoses & Workup: Toxicity, Valproate
Treatment & Medication: Toxicity, Valproate
Follow-up: Toxicity, Valproate
References
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Further Reading

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Keywords

valproic acid, toxicity valproate, valproate overdose, valproate poisoning, VPA, valproic acid overdose, anticonvulsant, antiseizure, seizure treatment, valproate, divalproate, sodium valproate toxicity, dipropylacetic acid toxicity, divalproex sodium toxicity, valproate semisodium toxicity, 2-propylpentanoic acid toxicity, 2-propylvaleric acid toxicity, Depacon, Depakene, Depakote, Depakote ER, Epilim, Ergenyl, Leptilan, Valkote, Sprinkles

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Contributor Information and Disclosures

Author

Timothy Wiegand, MD, Clinical Assistant Professor of Medicine, University of Vermont College of Medicine and Maine Medical Center; Associate Medical Director, Northern New England Poison Center
Timothy Wiegand, MD is a member of the following medical societies: American Academy of Clinical Toxicology, American College of Medical Toxicology, American College of Physicians, and Maine Medical Association
Disclosure: Nothing to disclose.

Coauthor(s)

Kent R Olson, MD, FACEP, Clinical Professor of Medicine and Pharmacy, University of California San Francisco; Medical Director, San Francisco Division, California Poison Control System
Kent R Olson, MD, FACEP is a member of the following medical societies: American Academy of Clinical Toxicology and American College of Medical Toxicology
Disclosure: Nothing to disclose.

Herbert E Hern Jr, MD, Assistant Clinical Professor, Department of Emergency Medicine, University of California, San Francisco; Residency Director, Department of Emergency Medicine, Highland General Hospital
Herbert E Hern Jr, MD is a member of the following medical societies: American College of Emergency Physicians and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Medical Editor

Lance W Kreplick, MD, MMM, FAAEM, FACEP, Medical Director of Hyperbaric Medicine, Fawcett Wound Management and Hyperbaric Medicine; Consulting Staff in Occupational Health and Rehabilitation, Company Care Occupational Health Services; President and Chief Executive Officer, QED Medical Solutions, LLC
Lance W Kreplick, MD, MMM, FAAEM, FACEP is a member of the following medical societies: American Academy of Emergency Medicine and American College of Physician Executives
Disclosure: Nothing to disclose.

Pharmacy Editor

John T VanDeVoort, PharmD, Regional Director of Pharmacy, Sacred Heart & 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.

Managing Editor

Fred Harchelroad, MD, FACMT, FAAEM, FACEP, Chair, Department of Emergency Medicine, Director of Medical Toxicology - Allegheny General Hospital, Associate Professor, Department of Emergency Medicine, Drexel University College of Medicine
Disclosure: Nothing to disclose.

CME Editor

John D Halamka, MD, MS, Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center
John D Halamka, MD, MS is a member of the following medical societies: American College of Emergency Physicians, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine
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.

 
 
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