Clinical Study Effects of Converting Tacrolimus Formulation from Twice-Daily to Once-Daily in Liver Transplantation Recipients Ashok Thorat, 1 Hong-Shiue Chou, 1 Chen-Fang Lee, 1 Ruey-Shyang Soong, 1 Tsung-Han Wu, 1 Chih-Hsien Cheng, 1 Ting-Jung Wu, 1 Kun-Ming Chan, 1 and Wei-Chen Lee 1,2 1 Department of Liver and Transplantation Surgery, Chang-Gung Memorial Hospital, College of Medicine, Chang-Gung University, Taoyuan, Taiwan 2 Department of Liver and Transplantation Surgery, Chang-Gung Transplantation Institute, Chang-Gung Memorial Hospital, 5 Fu-Hsing Street, Kwei-Shan, Taoyuan, Taiwan Correspondence should be addressed to Wei-Chen Lee; weichen@cgmh.org.tw Received 10 March 2014; Accepted 3 June 2014; Published 14 July 2014 Academic Editor: Jaime Aranda-Michel Copyright © 2014 Ashok horat 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. Typically, tacrolimus is administrated twice daily. Prolonged-release tacrolimus is the once-daily formulation and may be more convenient for patients. Experience with the administration of the once-daily formulation is still limited. his study enrolled 210 liver transplant recipients who had stable liver function and converted tacrolimus from a twice-daily to once-daily formulation on a 1 mg to 1 mg basis. Among 210 patients, seven patients (3.3%) were withdrawn from the once-daily formulation due to allergy and fatigue. For the other patients, the trough concentration ater converting to the once-daily formulation was lower than that of the twice-daily formulation. Liver enzymes were mildly elevated in 3 months ater formulation conversion and serum creatinine and uric acid were mildly decreased. Seven patients (3.4%) had clinical suspicion of acute rejection ater the formulation conversion and three of them were caused by nonadherence. 155 patients (76.4%) experienced a more convenient life with an increase of social activity. Forty-seven patients (23.2%) experienced the convenience of once-daily formulation during overseas trips. In conclusion, tacrolimus can be safely converted from the twice-daily to the once-daily formulation for most stable liver recipients. Acute rejection may occur in a minority of patients during formulation conversion and should be carefully monitored. 1. Introduction Liver transplantation is the only efective treatment for acute or chronic liver failure. Following liver transplantation, acute allograt rejection remains a signiicant cause of morbidity and may lead to grat dysfunction or failure if it is not treated promptly [1, 2]. By properly conducting immunosuppressive regimens, maintaining immunosuppression, and carefully monitoring drug levels, acute rejection can be successfully prevented or treated. he advances in immunosuppressive agents play an essential role in long-term allograt and patient survival [3, 4]. Cyclosporine, a calcineurin inhibitor, was introduced into transplantation medicine in the late 1970s and helped achieve great successes in solid organ transplanta- tion [5]. Tacrolimus is another potent calcineurin inhibitor introduced in 1989 and becomes one of the most popular immunosuppressive agents in liver transplantation now [6, 7]. Despite the progression of immunosuppressants, acute rejection still occurs in long-term survival patients. his acute rejection may be due to patients’ nonadherence to immunosuppressive treatment [2, 8, 9]. he incidence of nonadherence was estimated from 15% to 50% among solid organ transplant recipients [2, 10]. Conventionally, tacrolimus dosage is divided and administered orally every 12 hours to maintain stable trough levels of the drug. he transplant recipients are advised to take tacrolimus on an empty stomach more than one hour before or two to three hours ater a meal since oral bioavailability of tacrolimus is variable and absorption of tacrolimus is reduced by food [11, 12]. his requirement may be bothersome to some recipients and thus decrease adherence. herefore, attempts to reduce Hindawi Publishing Corporation BioMed Research International Volume 2014, Article ID 265658, 7 pages http://dx.doi.org/10.1155/2014/265658