Journal of Medical Toxicology

, Volume 3, Issue 1, pp 15–19 | Cite as

Evolving epidemiology of drug-induced seizures reported to a poison control center system

  • Josef G. ThundiyilEmail author
  • Thomas E. Kearney
  • Kent R. Olson
Toxicology Investigations



We sought to determine whether or not the causes and consequences of drug-induced seizures have changed in the last decade.


We conducted a retrospective review of all calls to the California Poison Control System in 2003 in which seizures occurred in association with poisoning or drug intoxication. We reviewed the poison center chart of each case to determine the drug(s) involved, the type of seizures, and the medical outcome. We compared the cause of reported seizures to that found in previous investigations.


386 cases were evaluated and related to poisoning or drug intoxication. The leading causes of seizures were bupropion (89 cases, 23%), diphenhydramine (32 cases, 8.3%), tricyclic antidepressants (30 cases,7.7%), tramadol (29 cases, 7.5%), amphetamines (27 cases, 6.9%), isoniazid (23 cases, 5.9%), and venlafaxine (23 cases, 5.9%). Since 1993, there was a statistically significant increase in antidepressant related seizures but a decrease in TCA and cocaine related seizures. In 265 patients (68.6%) only a single seizure was reported, while 3.6% (14 cases) reported status epilepticus. Two-thirds (65.5%) of the cases involved suicide attempts and 14.8% the direct result of drug abuse. There were 7 deaths. Of the 7 deaths, 4 people had significant hyperthermia. There was a statistically significant increased risk of death associated with stimulant exposure.


While tricyclic antidepressants, antihistamines, stimulants, and isoniazid remain common causes of drug induced seizures, bupropion, tramadol, and venlafaxine have emerged as common causes of drug-induced seizures for which poison center consultation is requested.


drug induced seizures status epilepticus seizure morbidity seizure complications 


  1. 1.
    Isbister GK, Downes F, Sibbritt D, Dawson AH, Whyte IM. Aspiration pneumonitis in an overdose population: frequency, predictors, and outcomes.Crit Care Med. 2004 Jan; 32(1): 88–93.PubMedCrossRefGoogle Scholar
  2. 2.
    Pesola GR, Avarsarala J. Bupropion seizure proportion among new-onset generalized seizures and drug related seizures presenting to an emergency department.J Emerg Med. 2002 Apr; 22(3): 235–9.PubMedCrossRefGoogle Scholar
  3. 3.
    Lowenstein DH, Alldredge BK. Status epilepticus at an urban public hospital in the 1980s.Neurology.1993 Mar; 43(3 Pt 1): 483–8.PubMedGoogle Scholar
  4. 4.
    Alldredge BK, Lowenstein DH, Simon RP. Seizures associated with recreational drug abuse.Neurology.1989 Aug; 39(8): 1037–9.PubMedGoogle Scholar
  5. 5.
    Olson KR, Kearney TE, Dyer JE, Benowitz NL, Blanc PD. Seizures associated with poisoning and drug overdose.Am J of Emerg Med. 1994 May; 12 (3): 392–395.CrossRefGoogle Scholar
  6. 6.
    Naranjo CA, Busto U, Sellers EM, Sandor P, Ruiz I, Roberts EA, et al. A method for estimating the probability of adverse drug reactions.Clin Pharmacol Ther 1981; 30: 239–45.PubMedGoogle Scholar
  7. 7.
    Ball J. Drug Abuse Warning Network. Trends in Drug-Related Emergency Department Visits, 1994–2002. The DAWN Report. November2003; accessed June 2006. Office of Applied Studies, SAMHSA. Available from: tp:// Scholar
  8. 8.
    Fountain NB. Status epilepticus: risk factors and complications.Epilepsia. 2000; 41 Suppl 2: S23–30.PubMedCrossRefGoogle Scholar
  9. 9.
    Rosenberg J, Pentel P, Pond S, Benowitz N, Olson K. Hyperthermia associated with drug intoxication.Crit Care Med. 1986 Nov; 14(11): 964–9.PubMedCrossRefGoogle Scholar

Copyright information

© American College of Medical Toxicology 2007

Authors and Affiliations

  • Josef G. Thundiyil
    • 1
    • 2
    Email author
  • Thomas E. Kearney
    • 1
  • Kent R. Olson
    • 1
  1. 1.California Poison Control System - San Francisco Division, School of Pharmacy, Department of Clinical PharmacyUniversity of CaliforniaSan Francisco
  2. 2.Department of Emergency MedicineOrlando Regional Medical CenterUSA

Personalised recommendations