Prevalence of the Shoulder Dislocation Due To Tramadol-Induced Seizure

background: seizure is a known cause of shoulder dislocation and has been reported as the adverse effect of tramadol consumption, with both therapeutic use and overdose.objectives: the present study aimed to determine the prevalence and type of the shoulder dislocation due to tramadol-induced seizure.patients and methods: this prospective and descriptive cross-sectional study was performed on patients with tramadol-induced shoulder dislocation referred to shafa orthopedic hospital, tehran, iran, from october 2012 to april 2013. the patients' data on age, sex, ingested dose of tramadol, previous history of tramadol or other drug abuse, history of previous tramadol-induced seizure before presentation, side and type of the dislocation, and presence of accompanying fractures were recorded.results: a total of 72 patients with shoulder dislocation were admitted during the study period. according to our eligibility criteria, 15 patients (20.83%) were included. all patients had consumed tramadol orally during the preceding four hours of seizure. the dosage of tramadol consumption ranged from 100 to 3500 mg (mean, 650 mg). all of patients were male aging between 22-43 years old (mean age, 29 ± 2.0 years). the side of dislocation was right in 9 (60%), left in 4 (26.66%), and bilateral in two patients (13.33%). all the dislocations were anterior, except one (6.66%). five patients (33.33%) had a history of another episode of previous tramadol-induced seizure. four patients (26.66%) had accompanying greater tuberosity fractures.conclusions: in patient with shoulder dislocation and without any obvious trauma, tramadol-induced seizure should be considered. tramadol should be prescribed cautiously and patients should be informed of its adverse effects including seizure-induced shoulder dislocation.