Trial of Prophylactic Tamsulosin for Postoperative Urinary Retention in Primary Total Hip and Knee Arthroplasty Patients

Inclusion Criteria: * Men age 35 or older * Primary total hip and knee arthroplasty patients (general, spinal, or epidural anesthesia * No current use (\>1 month) of alpha-blockers * Community ambulator * Adequate organ and marrow function as defined below: leucocytes at least 3,000/µL, absolute neutrophil count at least 1,500/µL, platelets at least 100,000/µL, creatinine within normal institutional limits * Ability to understand, and the willingness to sign, a written informed consent Exclusion Criteria: * History of radical prostatectomy * Receiving any other investigational agents * Revision hip and knee arthroplasty patients * Severe liver or kidney disease * Taking strong inhibitors of CYP3A4 (ketoconazole, itraconazole, clarithromycin, ritonavir, indinavir/ritonavir, lopinavir, or conivaptan) * Being on alpha-blockers (alfuzosin, doxazosin, prazosin, terazosin, tamsulosin, phenoxybenzamine, or silodosin) * Being of 5-alpha reductase inhibitors (finasteride, dutasteride) * History of allergy or sensitivity to tamsulosin or other alpha-blockers (alfuzosin, doxazosin, prazosin, terazosin, or phenoxybenzamine) * Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements * Taking Sildenafil,Tadalafil, or Vardenafil