Meptazinol hydrochloride is an injectable narcotic analgesic with antagonist
properties; it is similar in potency to meperidine. Meptazinol appears to have a
low propensity toward respiratory depression and other opiate-like side effects,
possibly due to selective interaction with the mu-1 receptor. Also somewhat
unique for an analgesic, it interacts with central cholinergic receptors. An oral
form of meptazinol is under development.
Mixed opioid agonist-antagonist. Analgesic (narcotic).
Analgesic;Opiate receptor agonist
Centrally active opioid analgesic. Partial agonist at the μ 1 opioid receptor. Also shown to inhibit acetylcholinesterase.
Meptazinol entered the human pharmaceutical market as a racemic mixture in the 1980s for use as an analgesic. Its pharmacology is not completely understood; however, its analgesic properties are mostly due to its partial agonism at the mu1 opioid receptor. Due to its partial agonism, Meptazinol antagonizes morphine dependence in vivo. Its advantage over other opiates is its reduced capacity to cause addition and respiratory depression, also due to its intrinsic activity as a partial agonist. Meptazinol has been found to have additional activity as an acetylcholinesterase (AChE) inhibitor, particularly in its (-) enantiomeric form, which may partially explain its analgesic properties. AChE inhibitors are used to treat Alzheimer′s disease, providing additional interest in this compound.