Buprenorphine is a semisynthetic opioid derivative of thebaine. It is a mixed partial agonist opioid receptor modulator that is used to treat opioid addiction in higher dosages, to control moderate acute pain in non-opioid-tolerant individuals in lower dosages and to control moderate chronic pain in even smaller doses. It is available in a variety of formulations: Cizdol, Subutex, Suboxone, Zubsolv, Bunavail (available as buprenorphine HCl alone or buprenorphine and naloxone HCl (see buprenorphine/naloxone); typically used for opioid addiction), Temgesic (sublingual tablets for moderate to severe pain), Buprenex (solutions for injection often used for acute pain in primary-care settings), Norspan and Butrans (transdermal preparations used for chronic pain).