Nicknamed "bupe," the drug is mostly sold in the United States as Suboxone, a formulation of four parts buprenorphine hydrochloride and one part naloxone hydrochloride, a chemical added to deter injection. The drug is also sold as Subutex, which has no additive. Each formulation is offered in 2 mg and 8 mg tablets that are to be taken under the tongue.
The long-acting opioid produces less respiratory depression at high doses than other narcotic treatment drugs. However, severe respiratory depression can occur when a person takes buprenorphine with other central nervous system depressants, especially benzodiazepines. Users are warned that death can result from this combination.
Source: Drug Enforcement Administration, Suboxone.com