Hindawi Publishing Corporation Case Reports in Psychiatry Volume 2013, Article ID 617251, 5 pages http://dx.doi.org/10.1155/2013/617251 Case Report Linezolid Is Associated with Serotonin Syndrome in a Patient Receiving Amitriptyline, and Fentanyl: A Case Report and Review of the Literature Lampros Samartzis, 1 Paraskevi Savvari, 2 Sofoklis Kontogiannis, 2 and Stavros Dimopoulos 2 1 Department of Psychiatry, Mental Health Services, Athalassa Psychiatric Hospital, 1452 Nicosia, Cyprus 2 Department of Clinical herapeutics, National and Kapodistrian University of Athens, Alexandra Hospital, 80 Vas. Soias Avenue, 11528 Athens, Greece Correspondence should be addressed to Stavros Dimopoulos; stdimop@med.uoa.gr Received 21 January 2013; Accepted 6 February 2013 Academic Editors: J. S. Brar and D. E. Dietrich Copyright © 2013 Lampros Samartzis et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. We report a unique case of an adverse interaction between the oxazolidinone antibiotic linezolid, the tricyclic antidepressant amitriptyline and the opioid analgesic fentanyl in a 68-year-old woman with advanced ischemic peripheral arterial disease and sepsis, under empirical antibiotic treatment. We also summarize the current relevant literature as identiied via PubMed, EMBASE, and PsycINFO as well as reference sections of selected articles. 1. Case Ms. B, a 68-year-old woman, presented at our outpatient clinic with intense lower foot pain and fever since a week. Clinical examination revealed the 3 irst phalanges of the let foot painful, cyanotic, and swollen in the absence of palpable pulsus at the ventral and dorsal tibial arteries with concomitant fever (38.5 ∘ C) and tachycardia (110 bpm). A complete blood count showed elevated total number of white blood cells (21 × 10 9 /L), consisted of 93% from neutrophil granulocytes. She was admitted to our hospital due to sepsis and possible diagnosis of infection of the ischemic let foot. Anamnestic history included advanced peripheral ischemic disease, diabetes mellitus type II, arterial hypertension, and major depression. he patient was receiving treatment with fentanyl transdermal patch 25 g/h every 72 h since 10 days and amitriptyline 25 mg BD for depression. he low dose of amitriptyline 25 mg BD was maintained due to its antidepres- sant [1, 2] as well as analgesic efects on chronic pain [3– 5] and especially painful diabetic limb [6–12]. During her stay in the medical ward, she was treated with empirical antibiotics including cloxacillin, 3rd generation beta-lactams, and aminoglycosides with an initial general improvement. However, at the 10th day patient had a new onset of high fever (38.7 ∘ C) and linezolid 600 mg every 12 hours was added to the treatment regimen and cloxacillin was stopped. Within the irst 24 hours of antibiotic change treatment, the patient had a rapid clinical deterioration manifesting symptomatology of restlessness, diaphoresis, tremor, shivering, myoclonus, and high fever (40 ∘ C), as well as gradual mental status disorders with disorientation, confusion, and coma. he patient was intubated due to severe respiratory diiculties according to the criteria of our clinic, and transferred to the intensive care unit. Brain computerized tomography and lumbar punc- ture (LP) for the exclusion of central neural system (CNS) infection were unremarkable. he constellation of the above neurological and mental state features in the presence of serotonergic medication [13–15] and the abstinence of other CNS pathology leads to the diagnosis of serotonin syndrome according to the diagnostic criteria of Hunter [16, 17] and Sternbach [14]. he irst signs of improvement appeared a few hours ater the interruption of linezolid and amitriptyline. Withdrawal of sedation and ventilator weaning took place 48 hours later. he patient gradually regained her consciousness and orientation to person, location, and time, as expected in the opposite order in which she lost orientation in the beginning of the confusion state [18].