Erythroxylum coca Lam. Erythroxylaceae Coca. Distribution: Peru . Cocaine is extracted from the leaf. It is no longer in the UK Pharmacopoeia (used to be used as a euphoriant in ‘Brompton Mixture’ for terminally ill patients). Cocaine, widely used as a local anaesthetic until 1903, inhibits re-uptake of dopamine and serotonin at brain synapses so these mood elevating chemicals build up and cause a ‘high’. Its use was often fatal. Coca leaf chewing was described by Nicolas Monardes (1569

in English,1577). It is a tropane alkaloid, euphoriant, local anaesthetic and stimulant. Its anaesthetic action is due to blocking of sodium channels and thus the propagation of action potentials down nerves from skin to spine. It is 'snorted’ as cocaine hydrochloride (cocaine + hydrochloric acid), so when the cocaine is absorbed the hydrochloric acid acts on the nasal septum and destroys it. Cocaine was first extracted in 1855 Niemann described analgesic effect in 1860 Cocawine sold 1863 eye operation by Koller in 1884 first synthesised in 1898 added to Coca-Cola 1886-1906 banned in 1902-1910. In 1930s Japan was the world's leading cocaine producer (23.3%) followed by the United States (21.3%). Now produced mostly in Colombia, Ecuador and Peru. Anti-drug officers spray plants with glyphosate – ‘Boliviana negra’ is a glyphosate resistant cultivar, produced in response to this attempt to eradicate it. Photographed in the Medicinal Garden of the Royal College of Physicians, London.