title: Tramadol exposures reported to statewide poison control system.
abstract: BACKGROUND
  Tramadol is a unique analgesic that has been associated with seizures on overdose.
  
  
  OBJECTIVE
  To determine the toxic effects associated with tramadol exposure.
  
  
  METHODS
  A retrospective chart review of tramadol exposures reported to a multisite, state-wide poison control system over a 2.5-year period was performed.
  
  
  RESULTS
  A total of 602 cases were retrieved; 190 had sufficient data for study evaluation. Cases with coingestants or unknown outcomes were eliminated. Of the 190 remaining cases, 55% were females. Acute ingestions represented 90.0%, chronic ingestions 7.9%, and acute on chronic 2.1% of the overdoses. Ages of the patients ranged from 9 months to 80 years. Suicide attempts represented the largest group of exposures. Main symptoms included central nervous system (CNS) depression (27.4%), nausea and vomiting (21.1%), tachycardia (17.4%), and seizures (13.7%). Dosage ranged from a taste amount to 5000 mg. The smallest amount of tramadol associated with seizure was 200 mg, and 84.6% of seizures occurred within 6 hours of time of ingestion. Logistic regression analysis showed an association between seizures and tramadol use in males, chronic use, suicide attempts, intentional abuse or misuse, and tachycardia (HR >100 beats/min). No effect was seen in 36.3% of patients, minor effects in 43.7%, moderate effects in 19.5%, and major effects in 0.5%. Symptoms resolved within 24 hours in 96.7% of the 121 patients who had symptoms. Naloxone improved CNS depression in 7 of 8 patients in whom a response was documented.
  
  
  CONCLUSIONS
  Tramadol overdoses frequently cause CNS depression, nausea/vomiting, tachycardia, and seizures. Symptoms generally resolve within 24 hours. Accidental ingestions in children were well tolerated, primarily causing sedation.
authors.affiliation: California Poison Control System, Sacramento Division, University of California Davis Medical Center, Sacramento, CA 95817-2201, USA. kmarquardt@calpoison.org
authors.forename: Kathy A
authors.initials: KA
authors.lastname: Marquardt
authors.forename: Judith A
authors.initials: JA
authors.lastname: Alsop
authors.forename: Timothy E
authors.initials: TE
authors.lastname: Albertson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000701:Analgesics, Opioid / Q000506:poisoning*; D002140:California / Q000453:epidemiology; D002490:Central Nervous System / Q000187:drug effects / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D003863:Depression / Q000139:chemically induced / Q000453:epidemiology; D062787:Drug Overdose; D005260:Female; D006801:Humans; D007223:Infant; D016015:Logistic Models; D008297:Male; D008508:Medication Errors / Q000706:statistics & numerical data; D008875:Middle Aged; D009325:Nausea / Q000139:chemically induced / Q000453:epidemiology; D011039:Poison Control Centers / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012640:Seizures / Q000139:chemically induced / Q000453:epidemiology; D012646:Self Administration / Q000706:statistics & numerical data; D012651:Self Medication / Q000706:statistics & numerical data; D013406:Suicide, Attempted / Q000706:statistics & numerical data; D013610:Tachycardia / Q000139:chemically induced / Q000453:epidemiology; D013997:Time Factors; D014147:Tramadol / Q000506:poisoning*; D014839:Vomiting / Q000139:chemically induced / Q000453:epidemiology
chemical_list: D000701:Analgesics, Opioid; D014147:Tramadol