Tramadol Induced Seizure: Report of 106 Patients

Background: Seizure is one of the possible adverse effects of tramadol hydrochloride, a synthetic, centrallyacting analgesic, prescribed for the treatment of moderate to severe pain. In this study, we describe 106 patients with tramadol induced seizures. Methods: The patients, who were referred to Nemazee Hospital, Shiraz, Iran, from March 2006 to March 2008, were examined in this cross-sectional study. All of the patients had experienced seizure(s) after ingesting tramadol. Each patient was interviewed for demographic data, history of epilepsy, family history of epilepsy, duration of tramadol use, total dose and the last dose of ingested tramadol. Neurological examinations, routine laboratory tests, electroencephalography, and brain computed tomography were performed for each patient. Results: One hundred and six patients were studied (102 males and 4 females, mean age: 26.7±6.9 years). Among them, 92 (86.8%) had new-onset provoked seizure(s) induced by tramadol and in 14 patients (13.2%), tramadol ingestion was considered as a precipitating factor in the setting of previously-known epilepsy. Tramadol was prescribed by the physicians for alleviation of pain in 20 patients (18.9%) and abused in the remainder (86 patients, 81.1%). The dose of ingested tramadol before the seizure(s) was 50 to 1500 mg. Conclusion: Tramadol may provoke seizures in patients with epilepsy and also in previously healthy people even within the recommended dose ranges. Because most of the cases had occurred in young abusers, strategies to prevent tramadol addiction should be sought.