Ms Louise Foxcroft (June 28, 2013). The Making of Addiction: The 'Use and Abuse' of Opium in Nineteenth-Century Britain. Ashgate Publishing, Ltd. pp.66–. ISBN 978-1-4094-7984-0. John K. Fairbanks, "The Creation of the Treaty System' in John K. Fairbanks, ed. The Cambridge History of China, vol. 10 Part 1 (Cambridge University Press, 1992) p. 213. cited in John Newsinger (October 1997). "Britain's opium wars – fact and myth about the opium trade in the East". Monthly Review. Archived from the original on February 13, 2006. Richard Askwith; The Sunday Times (September 13, 1998). "How aspirin turned hero" . Retrieved May 2, 2007. This section needs additional citations for verification. Please help improve this article by adding citations to reliable sourcesin this section. Unsourced material may be challenged and removed. ( February 2021) ( Learn how and when to remove this template message)

For the illegal drug trade, the morphine is extracted from the opium latex, reducing the bulk weight by 88%. It is then converted to heroin which is almost twice as potent, [6] and increases the value by a similar factor. The reduced weight and bulk make it easier to smuggle. Both analgesia and drug addiction are functions of the mu opioid receptor, the class of opioid receptor first identified as responsive to morphine. Tolerance is associated with the superactivation of the receptor, which may be affected by the degree of endocytosis caused by the opioid administered, and leads to a superactivation of cyclic AMP signaling. [155] Long-term use of morphine in palliative care and the management of chronic pain always entails a risk that the patient develops tolerance or physical dependence. There are many kinds of rehabilitation treatment, including pharmacologically based treatments with naltrexone, methadone, or ibogaine. [156] a b P. G. Kritikos & S. P. Papadaki (January 1, 1967). "The early history of the poppy and opium". Journal of the Archaeological Society of Athens.

The production methods have not significantly changed since ancient times. Through selective breeding of the Papaver somniferum plant, the content of the phenanthrene alkaloids morphine, codeine, and to a lesser extent thebaine has been greatly increased. In modern times, much of the thebaine, which often serves as the raw material for the synthesis for oxycodone, hydrocodone, hydromorphone, and other semisynthetic opiates, originates from extracting Papaver orientale or Papaver bracteatum. a b c d e f g h i j Paul L. Schiff Jr. (2002). "Opium and its alkaloids". American Journal of Pharmaceutical Education. Archived from the original on October 21, 2007 . Retrieved May 8, 2007. Santella, Thomas M.; Triggle, D. J. (2009). Opium. Facts On File, Incorporated. p.8. ISBN 9781438102139. Merlin, M. D. (September 2003). "Archaeological Evidence for the Tradition of Psychoactive Plant Use in the Old World". Economic Botany. 57 (3): 295–323. doi: 10.1663/0013-0001(2003)057[0295:aeftto]2.0.co;2. ISSN 0013-0001. JSTOR 4256701. S2CID 30297486 . Retrieved May 31, 2022.

Great Britain, India office (1922). The truth about Indian opium. [London] Printed by H.M. Stationery Off. Hai guan zong shui wu si shu (1889). The poppy in China. Shanghai; Statistical Dept. of the Inspectorate General of Customs. Zhang, Sarah (January 9, 2019). "Why a Medieval Woman Had Lapis Lazuli Hidden in Her Teeth". The Atlantic . Retrieved May 10, 2020. John Richards (May 23, 2001). "Opium and the British Indian Empire" . Retrieved September 24, 2007. Opium smoking began as a privilege of the elite and remained a great luxury into the early 19th century. However, by 1861, Wang Tao wrote that opium was used even by rich peasants, and even a small village without a rice store would have a shop where opium was sold. [47]Legal opium production is allowed under the United Nations Single Convention on Narcotic Drugs and other international drug treaties, subject to strict supervision by the law enforcement agencies of individual countries. The leading legal production method is the Robertson- Gregory process, whereby the entire poppy, excluding roots and leaves, is mashed and stewed in dilute acid solutions. The alkaloids are then recovered via acid-base extraction and purified. The exact date of its discovery is unknown, but it was described by Wurtz in his Dictionnaire de chimie pure et appliquée published in 1868. [138] Great Britain (1913). Agreement between Great Britain and Portugal for regulation of the opium monopolies of the colonies of Hong Kong and Macao. London, Printed for H.M. Stationery office. by Harrison and sons, ltd.