title: Factors related to seizure in tramadol poisoning and its blood concentration.
abstract: This study examines the relation between seizure and plasma tramadol concentration in patients with tramadol poisoning, as a novel centrally acting analgesic used for the treatment of mild to severe pain. All patients admitted with a history of tramadol overdose accompanied by unconsciousness or seizures referred to Baharloo Hospital Poison Center, Tehran, Iran from March 2008 to March 2009 were included. Demographic information, clinical findings, and blood tramadol concentrations were studied. There were 401 patients with a history of tramadol overdose; 121 (30.2%) with a history of seizure and 14 (3.5%) with a history of unconsciousness were included. Most of overdoses involved men (83%). The mean age was 22.9 years (range, 14-50 years). Intentional overdose was the most common mode of poisoning (51.9%). The mean dose ingested was 1,511 mg (SD, 1,353; range, 200-7,000). Mean back-extrapolated tramadol blood concentrations were 3,843 ng/mL (3,715; 269-20,049). Back-extrapolated blood concentrations were correlated with dose (r = 0.313; P < 0.001) as well as blood concentration levels (r = 0.801; P < 0.001). Seizure was significantly correlated to higher reported dose (P < 0.001) and tramadol only to overdose (P < 0.001). However, it was neither related to higher tramadol blood concentrations, nor related to time elapsed, age, sex, history of addiction, and observed Glasgow Coma Scale of patients. Most patients experienced just one seizure (76%). The tramadol-induced seizure is dose dependent. Although higher doses of tramadol was related to higher blood concentration, blood tramadol concentrations was not associated with seizure.
authors: Department of Forensic Medicine and Toxicology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
authors: Fakhreddin
authors: F
authors: Taghaddosinejad
authors: Omid
authors: O
authors: Mehrpour
authors: Reza
authors: R
authors: Afshari
authors: Alireza
authors: A
authors: Seghatoleslami
authors: Mohammad
authors: M
authors: Abdollahi
authors: Richard C
authors: RC
authors: Dart
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000701:Analgesics, Opioid / Q000097:blood* / Q000506:poisoning*; D002849:Chromatography, Gas; D004305:Dose-Response Relationship, Drug; D062787:Drug Overdose; D005260:Female; D015600:Glasgow Coma Scale; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011041:Poisoning / Q000453:epidemiology; D011446:Prospective Studies; D012640:Seizures / Q000139:chemically induced* / Q000503:physiopathology; D012737:Sex Factors; D014147:Tramadol / Q000097:blood* / Q000506:poisoning*; D055815:Young Adult
chemical_list: D000701:Analgesics, Opioid; D014147:Tramadol