Effects Of Dutasteride On Risk Reduction Of Acute Urinary Retention Relapse Following Trial Without Catheter

Inclusion Criteria: * Able to read, write and understand instructions related to study procedures and able to give written informed consent * Able to swallow and retain oral medication * Had a single, spontaneous episode of AUR related to BPH with a drained volume of between 500 and 1500ml * Had a successful TWOC (defined as successful if the patient returns to satisfactory voiding within the first 24 hours after catheter removal without re-catheterisation) following 2 - 3 days treatment with alpha blocker (preferably alfuzosin 10mg OD) pre TWOC followed by up to seven days treatment with alpha blocker (preferably alfuzosin 10mg OD) post TWOC. * Able to be randomised within 7 days of successful TWOC Exclusion Criteria: * Prostate volume (PV) of less than 30cc and greater than 80cc measured via Trans Rectal Ultrasound (TRUS) either at time of hospitalisation or as part of the screening / randomisation visit * Previous episode of AUR prior to the current episode * AUR not related to BPH i.e. postoperative retention following major abdominal / pelvis surgery * Previous prostate or urethral surgery * Previous positive prostate biopsy * Any cause other than BPH that may result in urinary symptoms or changes in flow rates. * Any unstable co-existing medical condition * Previous 5-ARI use * Previous alpha blocker treatment other than the study mandated 2 - 3 days pre and up to 7 days post TWOC period with alpha blocker (preferably alfuzosin 10mg OD) * Use of prohibited meds (e.g. 5ARI's, anabolic steroids including testosterone, drugs with antiandrogenic properties) * Liver enzymes (ALT, AST, ALP) at time of hospitalisation / screening visit greater than 2 x ULN or bilirubin at time of hospitalisation / screening visit greater than 1.5 x ULN. * Serum creatinine at time of hospitalisation / screening visit greater than 1.5 x ULN * Treatment with any other investigational product within 30 days prior to the first dose of study medication * History or current evidence of alcohol or drug abuse within the last 12 months * Prostate Specific Antigen (PSA) greater than 20ng/ml * Use of suprapubic catheterisation after failed urethral catheterisation * Neurogenic bladder dysfunction, confirmed or suspected, irrespective of etiology * Isolated bladder neck disease * Acute or chronic prostatitis * Confirmed or suspected urethral stricture * Known bladder stones * Clot retention secondary to haematuria of any cause * Patient unwilling to use a condom during sexual intercourse