Development of Non-Narcotic Analgesic Agents

Capsaicin [N-(4-hydroxy-3-methoxybenzyl)-trans-8-methyl -6-nonenamide], a pungent principle of red pepper. is known to induce analgesia. Though it has shown remarkable pharmacological activity, the toxicity and side effects inhibited its wider application. The interest has been renewed by the emergence of its agonists, resineferatoxin and ruthenium red. Recently, few successful capsaicinoids including 01vanil (NE-19550), NE-28345, and NE-21610 were reported.