European Review for Medical and Pharmacological Sciences 34 Abstract. – Background and Objectives: To determine the prevalence, type and site of the injuries due to tramadol-induced seizures in the patients who had referred after its overdose or use of its therapeutic dose. Material and Methods: All patients referring to Loghman Hakim Poison Hospital (February 2009 to April 2010) due to tramadol-induced seizures were included. The patients’ data in- cluding age, gender, ingested dose by history, route of exposure, manner of poisoning, previ- ous history of suicidal attempts, previous histo- ry of drug or substance abuse, history of tra- madol abuse, type of the seizure, number of episodes of seizure before presentation or after admission, site of the trauma, and type of injury were recorded. Results: A total of 232 patients were includ- ed in the study. Of them, 185 (79.7%) had re- ferred within the first 6 hours after ingestion. The mean dose ingested by the history was 1416±1124 mg. History of tramadol abuse was positive in 114 (49.1%) patients. Seizure episodes had occurred once in 207 (89.2%), twice in 21 (9.1%), and three times in 4 (1.7%) patients. The prevalence of trauma was 24.6% (in 57 patients) with the most frequent site of trauma to the face (9.5%) followed by shoulder (4.3%), head (3%), trunk (1.7%), and upper ex- tremities (1.3%). No statistically significant dif- ference was found between patients with and without trauma associated with tramadol-in- duced seizures in terms of age, gender, ingest- ed dose by history, positive history of addic- tion to other opioids, and number of episodes of seizure. Conclusions: The only serious injury asso- ciated with this type of seizure was the head injury, present in approximately 1% of the pa- tients. Key Words: Tramadol, Seizure, Trauma, Type of injury. Tramadol-induced seizures and trauma H. FARAJIDANA, H. HASSANIAN-MOGHADDAM*, N. ZAMANI, H. SANAEI-ZADEH Department of Forensic Medicine and Toxicology, Tehran University of Medical Sciences, Hazrat Rasoul Akram Hospital, Tehran (Iran) *Department of Clinical Toxicology, Loghman-Hakim Poison Hospital, Shahid Beheshti University of Medical Sciences, Tehran (Iran) Corresponding Author: Hossein Sanaei-Zadeh, MD; e-mail: h-sanaiezadeh@tums.ac.ir Introduction Tramadol is an analgesic with dual mechanism of action: induction of weak agonist effects at the μ opioid receptor and inhibition of serotonin and norepinephrine reuptake 1 . It is one of the most widely used analgesics due to its multimodal analgesic mechanisms 2,3 . One of the complications of the tramadol use is the seizure which is most often generalized tonic-clonic 4,5 . Attention to seizure-associated trauma is very important. However, evaluation of the prevalence of trauma has not been performed in the patients who refer with seizures after tra- madol overdose or as a side effect following the use of a therapeutic dose of it. The aim of this study was to determine the prevalence, type and site of the injuries due to tramadol-induced seizures in the patients who had referred after its overdose or use of its therapeutic dose. Materials and Methods In this retrospective study, all patients with tra- madol- induced seizures referring to Loghman Hakim Poison Hospital in Tehran, Iran between February 2009 and April 2010 were evaluated. Medical charts of all the admitted patients who had experienced seizures before presentation or after admission due to either tramadol overdose or as a side effect of its therapeutic use were identified using diagnosis code through the com- puter search from all those patients who had re- ferred with tramadol toxicity. The diagnosis of seizures before hospital presentation had been confirmed by an accurate medical history taken from the people accompanying the patient or the 2012; 16(Suppl 1): 34-37