Buprenorphine and naloxone are often combined to decrease withdrawal symptoms in opioid dependent individuals. Buprenorphine/naloxone is usually given daily to individuals who are attempting to stop opioid abuse; however, research suggests that individuals may be more inclined to take medication if it is given in less than daily intervals. The purpose of this study is to examine the opioid blockade effects of buprenorphine/naloxone that is administered in less than daily doses to opioid dependent individuals.