Advance Reported in Nonaddictive Painkiller
Researchers create plant that doesn't produce morphine
WEDNESDAY, Sept. 22, 2004 (HealthDayNews) -- While the opium poppy is the source for compounds needed to make potent painkillers such as oxycodone and other medicines, it is also the source for the illegal drug heroin.
Australian researchers say they have solved that problem by creating a plant that does not produce morphine, but only the compounds thebaine and oripavine, which can be developed synthetically into nonaddictive painkillers. Their report appears in the Sept. 24 issue of Nature.
"We have uncovered a variant of the opium poppy that does not make morphine or codeine," said lead researcher Philip J. Larkin, a senior principal research scientist from the Commonwealth Scientific and Industrial Research Organization in Acton. "Instead, it accumulates two molecules that occur in the pathway before morphine, namely thebaine and oripavine."
The legal growers of poppies use thebaine and oripavine in the synthesis of valuable and powerful painkillers and treatments for drug overdose and alcoholism, such as oxycodone (OxyContin), buprenorphine (Subutex), naloxone (Narcan) and naltrexone (ReVia), Larkin said.
This new poppy makes it easier to get these compounds from the plants and also increases the yield of thebaine and oripavine in each plant. "By having crops that produce these compounds undiluted, enormous efficiencies have been put into the process of manufacturing these pharmaceuticals," he said.
Poppy farmers in Tasmania are already growing this new poppy on more than 50 percent of their land. Tasmania grows more than 40 percent of the world's legally traded opium, Larkin said. The development of this new poppy was a joint effort between the Tasmanian Alkaloid Co., supplier of thebaine and oripavine, and the Australian government.
India, France, and some Eastern European countries also produce legal opium.
By manufacturing thebaine more efficiently, oxycodone, and buprenorphine can be made more efficiently and in larger quantities, Larkin said.
Larkin's team has also been trying to understand the genetic changes in the poppy they created. "This will allow us to engineer the plant for other pharmaceutical purposes, such as anticancer agents," he said.
"An ingenious and brave colleague from the Tasmanian Alkaloid Co. had the idea to simply mutate seeds of opium poppies," said Meinhart H. Zenk, a professor of plant biology from University Halle in Germany. "The result was surprising and yielded stable mutants."
"We all would have suspected that mutation of diploid seeds would lead nowhere, but he had the guts to successfully try it," Zenk said.
The National Institute of Neurological Disorders and Stroke discusses how to cope with chronic pain.