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Is Big Pharma Trying to Take All the Fun out of Pot?

Drug researchers are trying to replicate marijuana's therapeutic effects, but without the "side effect" of getting people high.

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"You can't get permission to even touch the marijuana," says Armentano.

Fewer obstacles exist in Europe. But when Weleda AG, a German herbal-medicine and cosmetics company, funded a British study of THC-CBD extract for multiple-sclerosis spasticity, it was terminated for lack of volunteers.

Generic forms of Marinol, THC under the name "dronabinol," are beginning to reach the U.S. market. Two leading generic-drug manufacturers, Par Pharmaceutical and Watson Pharmaceuticals, began selling it last year, with Watson the authorized licensee of Solvay.

Bionorica AG, a veteran German herbal-medicine company, is seeking FDA approval for a version of dronabinol containing THC extracted from plants. The company has been selling it in pharmacies in Germany and Austria for the past 10 or 12 years, says Gary Klein, its U.S. representative. It's also looking at developing THC in droplets that would be absorbed on the underside of the tongue.

ElSohly, who has the U.S. government monopoly on research cannabis, is working with Mallinckrodt to develop a plant-extract form of Marinol. Medical-cannabis advocates sharply criticize him for that. Americans for Safe Access charges that he "benefits from such a monopoly by financially profiting from the research and sale of cannabis-based pharmaceuticals."

ElSohly has also patented a suppository containing THC hemisuccinate, which breaks down into THC once it is absorbed by the body. That is "not a popular form of drug delivery," observes the anonymous medical-marijuana researcher. (The 1960s comedian Lenny Bruce would disagree; he enjoyed morphine suppositories.)

Cannasat Therapeutics, a Canadian company, is applying to patent a THC pill called Relivar for neuropathic pain. Like some triptan migraine-abortive drugs, the pill would melt in the mouth instead of having to be digested. The company claims that this will make the drug act faster, get a higher proportion of it into the blood, and make it less intoxicating than oral THC pills. Cannasat is also working on a CBD-based treatment for schizophrenia.

Research into the cannabinoid agonists-drugs, which enhance cannabinoids binding to receptors in the brain and body, has mainly been "preclinical," with tests on animals instead of humans, according to Kunos. Drug companies, he adds, have strong objections to them because they would be psychoactive, essentially mimicking the action of marijuana in the brain.

Pharmos, an Israeli company, had high hopes for a nonpsychoactive synthetic cannabinoid called HU-211. Preliminary studies indicated that it could protect the brain from the cascading neurochemical inferno set off by a stroke or traumatic injury, but Phase III studies in 2004 found it not significantly more effective than a placebo.

A fourth area is drugs that inhibit FAAH, the enzyme in the brain that breaks down the endocannabinoids anandamide and 2AG. These would work in a manner roughly analogous to antidepressants like Prozac, which inhibit the reuptake of serotonin. Danielle Piomelli of the University of California at Irvine has patented several possible FAAH-inhibiting medications, including an anxiety reducer, a cough suppressor and a pain reliever.

Finally, research into cannabinoid antagonists continues. Kunos says the goal now is to find one that's "non-brain-penetrant," a drug that would affect only cannabinoid receptors outside the brain, and therefore wouldn't have the psychiatric side effects that derailed rimonabant. He says the animal models are promising.

7TM Pharma, a Danish company that specializes in drugs for metabolic disorders, plans to start trials of a cannabinoid antagonist this year in the treatment of obesity and Type 2 diabetes. It says the drug "has been designed to exclusively exert its therapeutic effect through CB1 receptors located in the peripheral tissue" instead of those in the brain.