November 1, 2013

Experts debate effectiveness of medical marijuana

Research has yet to nail down if, and how, the drug works on specific diseases.

By Ellen Jean Hirst
Chicago Tribune

(Continued from page 1)

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Mike Graham poses at his home in Manteno, Ill., with medications he used to take for degenerative disc disease. Graham began using medical marijuana about five years ago, which allowed him to stop using most of the pharmaceuticals for pain relief.

John J. Kim/Chicago Tribune/MCT

Increasingly desperate, in 2002, he decided to give it a try. He was able to cut back on all his previous medications except a morphine pump under his skin. Now, he takes three or four puffs of marijuana in the morning and at night. Once down to 135 pounds, the more than 6-foot-tall Graham now says he’s back up to 250 after regaining his appetite.

“What it comes down to here (is) I wouldn’t be here if I hadn’t made that decision,” Graham said.

While stories like Graham’s are plentiful, doctors and researchers say the nonmedical elements of the plant could have sometimes serious adverse effects.

Dr. Eric Voth, a Topeka, Kan., internist and pain specialist and chairman of the Institute on Global Drug Policy, said relying on anecdotal evidence is dangerous because other factors could influence why patients start to feel better.

“It’s very hard to differentiate whether somebody feels better because they’re stoned or because they’re getting a true therapeutic benefit from the drug,” Voth said.


Smoking marijuana could increase the risk of cancer because of inhalation of tar and other carcinogens in the plant, Voth said. While proponents of its use point to the 105 unique compounds that may be useful for medicine, there are hundreds more compounds in marijuana that some scientists believe not only have no use but may be harmful.

“You’ve still got (hundreds of other) substances in there,” Voth said. “It just (shouldn’t) be smoked. That is a crazy precedent.”

Illinois’ law allows dispensaries to sell marijuana-infused baked goods in addition to joints, but advocates say it takes longer to feel the effects of marijuana when it’s ingested instead of smoked.

Several papers in scientific journals have found that marijuana use over a long period of time can have negative cognitive effects, too. Users can’t concentrate or remember as well as before, in some cases years after they have quit.

Voth said he doubts that even identifiable benefits would be enough to outweigh the negative effects, because of other potentially harmful components that are mixed in.

“Essentially what they are, are toxic chemicals,” Voth said. “None of those things would you ever mix with medicine.”

In 1937, the U.S. criminalized marijuana, and today it’s considered a Schedule I drug, along with heroin and LSD.

The FDA approved a synthetic THC pill called Marinol in 1985, acknowledging the drug’s benefits for people with nausea and decreased appetite. In Canada and some parts of Europe, a similar drug called Sativex – containing synthetic THC and cannabidiol – has been approved in recent years, offered as an oral spray. In the late 1980s, scientists discovered a previously unknown biological system called the endocannabinoid system, which proponents for marijuana theorize could show how it works.

The National Institutes of Health reported in 2006 that the system holds “therapeutic promise in a wide range of disparate diseases.”

But experts say more research is needed before determining exactly what the system may be able to do.Mary Lynn Mathre, a founding partner of Patients Out of Time, a marijuana advocacy group that focuses on health issues, said the leading theory regarding the system is that the human body has cannabinoid receptors – essentially keyholes that cannabis compounds fit into, helping the body regulate.

“You take cannabis, which has similar chemicals that we need, and you put it in the body and they work if we’re not making the cannabinoids that we need,” said Mathre, a longtime registered nurse. “You can liken this to a diabetic. Their pancreas isn’t making insulin, so we give them insulin. If our body can’t make this chemical, there happens to be this plant on earth that is there to supply us.”


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