Opioid Ligands Having Delayed Long-Term Antagonist Activity: Potential Pharmacotherapies for Opioid Abuse

Buprenorphine is a partial agonist at the μ-opioid receptor with long duration of action and also exhibits delayed antagonist activity. Buprenorphine is finding increasing use as a treatment agent for opioid abuse, though its low efficacy is not well tolerated by all addicts. There is interest in developing a higher efficacy version of buprenorphine and in this mini-review some of the ligands recently discovered, that share with buprenorphine a profile of agonism followed by delayed antagonism, are discussed.