tebaína

Thebaine, known as tebaína in Portuguese, is an alkaloid of the morphinan class found in the opium poppy Papaver somniferum. It occurs in opium in small amounts compared with morphine and codeine. Thebaine has little direct analgesic effect in humans and is not used clinically for pain relief. Its primary significance is as a chemical precursor in the manufacture of semi-synthetic opioids, including buprenorphine, etorphine, and other oripavines.

Chemically, thebaine is a 3,6-dimethoxy derivative of the morphinan skeleton, with a double bond at positions 7,8 and an epoxide bridge. Its two methoxy groups distinguish it from morphine and contribute to its distinct pharmacological profile. Thebaine binds weakly to opioid receptors and, at high doses, can be convulsant in experimental settings; these properties limit its direct therapeutic use.

Natural origin and production: Thebaine is produced by the opium poppy but is typically present at relatively low levels in the latex. Concentration varies by cultivar and growing conditions. Purified thebaine is obtained by extraction and separation from opium, followed by chemical modification for downstream synthesis.

Regulation and use: Because thebaine is a controlled precursor used to synthesize potent opioids, its sale, possession, and transport are restricted under national and international drug-control laws. In many jurisdictions, it is treated separately from morphine and codeine in terms of licensing and monitoring.