Buprenorphine HCL (subutex) is a drug used to treat opioid dependency AND also used to treat chronic pain. Doctors need a special rx # to be able to prescribe Subutex (buprenorphine) for opiate addictions BUT any doctor can prescribe it for pain. This loophole is because the FDA recognizes this drug to only treat opiate dependency and NOT for pain, however it is one of the best pain relievers out there. For a doctor to prescribe it for pain ... this is called 'off label' prescriptions aka using a medicine for something other than what it was intended, which the FDA has no regulations over.
Buprenorphine comes in different forms. From sublingual pills to a liquid that is used intramuscular. It IS a narcotic and is a derivative of Thebaine, an extract of opium. It is a partial antagonist whereas drugs such as heroin and other hardcore opiates are full antagonist. This means that it gives you the partial effects that other opiates give you such as euphoria and decreased respiratory rate.
Used to treat pain: binds to the same receptors in the brain that other opiates bind to giving it similar pain fighting effects since the receptors that recognize pain are the ones that are being bound to.
Used for opiate addiction: The drug binds to the same opioid receptors as the abused opiate that someone is using which creates the same effects the drug gives the person, just not as potent. Cravings are reduced by this and it becomes easy to taper off the drug to reduce tolerance.