A significant overlap of drug concentrations exists in body fluids within the possible spectrum of physiological reactions ranging from asymptomatic to comatose. Therefore, having knowledge of both the route of administration of the drug and the level of tolerance to opioids of the individual is critical when results are interpreted. History
In 1969, researchers at Reckitt and Colman (now Reckitt Benckiser) had spent 10 years attempting to synthesize an opioid compound "with structures substantially more complex than morphine [that] could retain the desirable actions whilst shedding the undesirable side effects". Physical dependence and withdrawal from buprenorphine itself remain important issues, since buprenorphine is a long-acting opioid. Reckitt found success when researchers synthesized RX6029 which had showed success in reducing dependence in test animals. RX6029 was named buprenorphine and began trials on humans in 1971. By 1978, buprenorphine was first launched in the UK as an injection to treat severe pain, with a sublingual formulation released in 1982. Society and culture
Regulation
United States
In the United States, buprenorphine and buprenorphine with naloxone were approved for opioid use disorder by the Food and Drug Administration in October 2002. The DEA rescheduled buprenorphine from a schedule V drug to a schedule III drug just before approval. The ACSCN for buprenorphine is 9064, and being a schedule III substance, it does not have an annual manufacturing quota imposed by the DEA. The salt in use is the hydrochloride, which has a free-base conversion ratio of 0.928.
: 84–5   In France, buprenorphine prescription for opioid use disorder has been permitted without any special training or restrictions since 1995, resulting in treatment of approximately ten times more patients per year with buprenorphine than with methadone in the following decade. In 2021, seeking to address record levels of opioid overdose, the United States also removed the requirement for a special waiver for prescribing physicians. Whether this change will be sufficient to impact prescription is unclear, since even before the change as many as half of physicians with a waiver permitting them to prescribe buprenorphine did not do so, and one third of non-waivered physicians reported that nothing would induce them to prescripe buprenorphine for opioid use disorder. Chronic pain
A transdermal patch is available for the treatment of chronic pain. These patches are not indicated for use in acute pain, pain that is expected to last only for a short period of time, or pain after surgery, nor are they recommended for opioid addiction. Potency
With respect to equianalgesic dosing, when used sublingually, the potency of buprenorphine is about 40 to 70 times that of morphine. When used as a transdermal patch, the potency of buprenorphine may be 100 to 115 times that of morphine. Veterinary uses
Veterinarians frequently administer buprenorphine for perioperative pain, particularly in cats, where its effects are similar to morphine. The drugs legal status and lower potential for human abuse makes it an attractive alternative to other opioids.