Clinical pharmacology of buprenorphine with respect to management of opioid dependence

Buprenorphine is a semi-synthetic opioid derived from the morphine alkaloid thebaine

• is a mixed agonist-antagonist and its primary action is as a partial opiate agonist
• buprenorphine produces opioid responses while also reducing the effect of additional heroin, methadone or morphine

Buprenorphine (1):

• has low intrinsic agonist activity, only partially activating mu opioid receptors, and consequently high buprenorphine doses produce a milder, less euphoric and less sedating effect than high doses of other opioids such as heroin, methadone or morphine. However, it exerts sufficient opiate effects to prevent or alleviate opioid withdrawal including craving
• has a high affinity for mu receptors and binds more tightly than heroin, methadone or morphine. It reduces the impact of additional opioid use (when prescribed in doses greater than 8 mg) by preventing the receptors being occupied by these additional opioids
• binds strongly to kappa opioid receptors where it acts as an opioid antagonist

Reference:

1. Royal College of General Practitioners (UK). Guidance for the use of buprenorphine for the treatment of opioid dependence in primary care, second edition 2004.