Thebaine (paramorphine), also known as codeine methyl enol ether, is an
opiatealkaloid, its name coming from the
Greek Θῆβαι, Thēbai (Thebes), an ancient city in
Upper Egypt. A minor constituent of
opium, thebaine is chemically similar to both
morphine and
codeine, but has stimulatory rather than depressant effects. At high doses, it causes convulsions similar to
strychnine poisoning. The synthetic
enantiomer (+)-thebaine does show analgesic effects apparently mediated through opioid receptors, unlike the inactive natural enantiomer (−)-thebaine.[3] While thebaine is not used therapeutically, it is the main alkaloid extracted from Papaver bracteatum (Iranian opium / Persian poppy) and can be converted industrially into a variety of compounds, including
hydrocodone,
hydromorphone,
oxycodone,
oxymorphone,
nalbuphine,
naloxone,
naltrexone,
buprenorphine,
butorphanol and
etorphine.[4]
Thebaine is controlled under international law, is listed as a Class A drug under the
Misuse of Drugs Act 1971 in the United Kingdom, is controlled as an analog of a Schedule II drug per the
Analog Act in the United States, and is controlled with its derivatives and salts, as a Schedule I substance of the
Controlled Drugs and Substances Act in Canada.[5] The 2013 US
Drug Enforcement Administration (DEA) aggregate manufacturing quota for thebaine (ACSCN 9333) was unchanged from the previous year at 145 metric tons.
In 2012 there was an amounted 146,000 kilograms of thebaine produced.[7] In 2013, Australia was the main producer of
poppy straw rich in thebaine, followed by Spain and then France. By 2017, worldwide thebaine production dropped to 2,008 kg.[8] Together, those three countries accounted for about 99 per cent of global production of such poppy straw. The
Papaver bracteatum seed capsules are the primary source of thebaine, with the stem additionally yielding a significant amount.[9][10]
The Canberra Times of 16 November 2022[11] reported that four batches of Hoyts brand
poppy seeds were being recalled due to unusually high levels of thebaine, and that at least twelve people in
New South Wales had required medical attention after ingesting them. As of 15 November 2022,
Food Standards Australia New Zealand (FSANZ) is coordinating a national recall of a number of poppy seed products due to the potential presence of thebaine.[12]
^Mikus, G.; Somogyi, A. A.; Bochner, F.; Eichelbaum, M. (1991). "Thebaine O-demethylation to oripavine: Genetic differences between two rat strains". Xenobiotica. 21 (11): 1501–9.
doi:
10.3109/00498259109044400.
PMID1763524.
^Aceto, M. D.; Harris, L. S.; Abood, M. E.; Rice, K. C. (1999). "Stereoselective μ- and δ-opioid receptor-related antinociception and binding with (+)-thebaine". European Journal of Pharmacology. 365 (2–3): 143–7.
doi:
10.1016/S0014-2999(98)00862-0.
PMID9988096.