Association Between Readmission After Liver Transplant and Adverse Immunosuppressant Reactions: A Prospective Cohort With a 1-Year Follow-up L. Haddad*, K. Andrade, L. Mendes, L. Ducatti, L.A. D’Albuquerque, and W. Andraus Liver and Gastrointestinal Transplant Division, Department of Gastroenterology, University of São Paulo School of Medicine, São Paulo, Brazil ABSTRACT Objective. To measure the association between readmission after liver transplantation and corresponding adverse drug reactions. Methods. A total of 48 patients undergoing liver transplantation were prospectively followed for 1 year. Of these, 23 were readmitted and evaluated by a pharmacist for causes of adverse drug reaction. The detection of adverse drug reactions was based on a combi- nation of clinical interviews and physical and laboratory exams. Adverse reactions were defined in accordance with the Naranjo algorithm. Results. A total of 67.6% of all readmissions were related to adverse drug reactions, with tacrolimus accounting for 80% of the drug reactions. The most common cause of read- mission was infection (48.6%), followed by procedure-related reasons (29.7%). Of all patients requiring admission, 39.1% had Model for End-stage Liver Disease (MELD) scores below 21 at the time of transplantation, 17.4% had MELD scores between 21 and 29, and 43.5% had MELD scores above 29. Most (66.7%) of those readmitted more than twice had MELD scores above 29. Conclusion. Adverse drug reactions related to immunosuppressants frequently lead to readmission among liver transplant patients, and in our series tacrolimus was the most frequently associated drug. L IVER transplantation is the treatment of choice for a number of irreversible liver conditions, both chronic and acute [1]. Immunosuppressant therapy plays a key role in postoperative patient management [2], with drug dosage adjusted on an individual basis to achieve maximum effec- tiveness and to reduce risks of rejection, infection, neoplasia, and immunosuppressant-related toxicity [3]. Adverse drug reactions are common during this period, frequently leading to hospital readmission as well as increased rates of morbidity and mortality, deterioration in quality of life, and increased hospital costs [4]. Despite the importance of adverse drug reactions leading to hospital readmission, to our knowledge no previous articles have prospectively evaluated readmissions at the point of care by a specialized pharmacist, thus ensuring the accuracy of each data point. Among liver transplant patients, drug interactions are important in that they might affect the ability to maintain immunosuppressive regimens within an effective range. The goal is therefore to keep drug levels high enough to avoid toxicity, while also not as low to generate rejection. Among immunosuppressant drugs, calcineurin inhibitors such as tacrolimus or cyclosporine are among the most commonly used drugs. Elevated levels of calcineurin inhibitor are commonly associated with nausea, headache, somnolence, cognitive impairment, hypertension, tremor, seizures, and acute renal failure [5,6]. Increased levels of mycophenolate will infrequently lead to adverse events, although reports *Address correspondence to Luciana Bertocco de Paiva Haddad, PhD, Liver and Gastrointestinal Transplant Division, Department of Gastroenterology, University of São Paulo School of Medicine, Rua Aracaju 42 ap 41, São Paulo SP CEP 01240030, Brasil. E-mail: luciana.haddad@hc.fm.usp.br 0041-1345/17 http://dx.doi.org/10.1016/j.transproceed.2016.12.005 ª 2016 Elsevier Inc. All rights reserved. 230 Park Avenue, New York, NY 10169 330 Transplantation Proceedings, 49, 330e337 (2017)