Key Questions Cloud Medical Pot Debate

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KEY QUESTIONS CLOUD MEDICAL POT DEBATE

 

TAMPA - On the fourth floor of a hivelike, 1970s-vintage lab building on the University of South Florida's medical campus, Thomas Klein has spent 25 years studying marijuana's effects on the immune systems of mice, blowfish and human beings.

 

If anyone should be able to answer the question that has surrounded pot for decades -- How bad is it for you? -- it should be Klein.

 

Klein, 66, a tall, courtly professor of immunology and molecular medicine, can tell you he is very close to solving a few puzzles about the connection between cannabinoids -- the active compounds in marijuana -- and common allergies. But like other researchers in the field, Klein says marijuana's health effects remain a daunting mystery.

 

Solving that mystery grows more urgent as efforts to legalize marijuana, at least for medical use, gain momentum. Arizona this month became the 15th state to make it possible for adults to get a doctor's prescription for marijuana. Add to this an estimated 15.2 million illicit users across the country -- including Florida, where the drug remains illegal in all cases, but also readily available.

 

Unlike alcohol and tobacco, proponents say, marijuana has not been proven to be a danger to users or to society. Instead, they say, it can relieve pain and treat other medical problems, with fewer side effects than many legal drugs.

 

To which scientists like Klein respond: The jury's still out.

 

"We used to think it affected your brain," Klein said. "Now we know it affects all the cells in your body. It won't kill you, but it will change your immune system. Over time, some of these changes might not be beneficial."

 

One reason that marijuana's effects remain hard to quantify is that it affects people differently. Almost anyone who drinks several shots of vodka will be intoxicated. But not everyone who smokes a joint becomes stoned. Some just become more relaxed.

 

The health risks and benefits also vary greatly.

 

Scientists agree that as a medical treatment, marijuana has shown to ease excruciating pain from arthritis to bone cancer. It also benefits some patients suffering from glaucoma or AIDS-related weight loss. But others get no benefit at all, and no one yet knows why.

 

The effects on recreational users are even less understood. Studies of habitual smokers remain small, underfunded and cumbersome to pursue.

 

Dr. Bruce Robinson, a Sarasota gerontologist and an expert on dementia, said marijuana appears to cause short-term memory and lapses in cognition. It has also been linked to "amotivational syndrome" -- which might, in laymen's terms, be described as the inability to get off the couch and get a job.

 

But, unlike with alcohol, there is no strong evidence that "marijuana produces permanent deficits in memory and thinking."

 

"Alcohol is a much more dangerous drug," Robinson added.

 

Deterring Research

 

Another reason that marijuana is not as well understood is that it has been the subject of fewer studies than many other drugs.

 

Pot remains classified as a Schedule I controlled substance -- which basically defines it as a dangerous drug with no medical value. This alone deters scientific study, said Dr. Igor Grant, director of the Center for Medicinal Cannabis Research at the University of California, San Diego.

 

"My view is that the federal government should reschedule marijuana, and that would stimulate research," Grant said. "Right now, it's too difficult to fool around with a Schedule I drug. You have to go through all these regulatory steps."

 

According to a search of the National Library of Medicine's PubMed database, the number of journal articles on the subject went from 258 in 1996 to 2,603 in 2009. But a similar search for work on aspirin last year yielded more than 7,000 articles. For steroids, the number topped 97,000. And most of the pot research, Grant said, involves small samples of patients.

 

"The next step is to do a larger study," he said. "I think it's fair to conclude that cannabis can be useful, that it can be another arrow in the quiver to treat difficult conditions."

 

But, he added, "We don't know how elderly people respond as opposed to middle-aged people. What if there are complicating conditions? We know cannabinoids can speed up your heart, for instance, and lower the blood pressure. What will that do over time? We don't know."

 

Medical marijuana activists counter that the federal government does not want to know. Irvin Rosenfeld, 57, of Fort Lauderdale is one of four surviving subjects of the National Institute on Drug Abuse's unusual "compassionate use" program, begun in 1978 in response to legal appeals by individual patients. The program closed to new patients in 1992.

 

Every 25 days, Rosenfeld receives 300 marijuana cigarettes from the government, grown and rolled at the University of Mississippi, home to NIDA's Marijuana Project at the National Center for Natural Products Research. He has been smoking at least 10 a day since 1982 to control a rare and once-disabling bone disorder. But NIDA, he said, has shown no interest in studying the human volunteers in this unusual long-term trial that it continues to fund.

 

"You would think so, wouldn't you?" Rosenfeld asked. "That's as far from the truth as can be. The federal government doesn't want to know that cannabis works. Even though my doctor fills out reports twice a year, nobody reads them."

 

USF's Klein explained why cannabis has a unique impact on each individual.

 

"In some people the drugs are metabolized differently," he said. "Their receptors for the drug might be a little bit different." For pot to help, he said, "you ingest the drug and it has to get to the right receptors, and those receptors have to be there and functioning in a certain way, so that you have X amount of the drug and 20X amount of effect. These are all the differences that we have just begun to appreciate."

 

Medical Benefits

 

Science has yielded some reliable conclusions about pot's benefits. Grant's institute has backed up other studies on its usefulness in combating neuropathy, which he described as a "dull, burning pain." Since nerve pain is so resistant to available drug therapies, marijuana's potential here is significant, said Klein.

 

"We read about this in the newspaper and say, 'Well, we all have pain from time to time,'" he said. "But real, chronic neuropathic pain can be debilitating."

 

Other conditions where marijuana has proven of some help include glaucoma, multiple sclerosis, Parkinson's disease and the nausea that attends chemotherapy. Sufferers from ALS, or Lou Gehrig's disease, have found relief, and cannabis has proven so good at dulling the aches and pains that come with age that some policy analysts predict it will become the drug of choice as baby boomers begin to populate nursing homes.

 

In most cases, smoking pot seems to work better than ingesting it orally. But large studies have linked long-term marijuana habits to lung damage.

 

"There are some people who will argue that smoking is never going to be an acceptable way to deliver a medicine," Grant said. "At the moment, smoking is one of the practical delivery systems. This has to do with the unusual absorption and distribution effects of cannabis when taken by mouth; it's very difficult to zero in on the exact right level. If you're smoking, you can control how quickly you're inhaling, and stop smoking once you start getting the effect."

 

Grant and Klein said studies are under way to determine whether vaporizing cannabis -- so that it can be inhaled without combustion - -- might deliver the same benefits.

 

Another variable in society's ongoing uncontrolled experiment with marijuana is its potency. THC -- short for delta-9-tetrahydrocannabinol -- is the drug's most active ingredient, producing a high and also relieving symptoms in some people. The NIDA Marijuana Project, analyzing confiscated pot, found that the average level of THC climbed steadily from seven-tenths of a percent in 1975, with jumps to 2 percent in 1980 and 3 percent in 1982, to a record 8.5 percent in 2008. The rise was much more dramatic with imported cannabis than the homegrown variety.

 

Despite these imponderables, Grant is hopeful that greater knowledge will unlock more of marijuana's gifts and curb its dangers.

 

"I think we're learning quite a lot about cannabinoid receptors," he said. "We do know that in the nervous system they're kind of like a shock absorber; they seem to downregulate some signals from other systems.

 

"But so much more needs to be learned," he added. "We have plenty of other medications that act on systems in ways we don't understand very well, and yet they are legal. Antidepressants are a good example of that."

 

Klein said if the legalization trend continues, scientific research should keep pace with it.

 

"I can understand why people want to see marijuana legalized, because it does work for some people," he said. "But along with that comes a responsibility to monitor what kinds of effects this greater access is having on the population. We can't just make it more available and turn our backs -- and then be surprised if something untoward starts happening."

 

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MEDICAL MARIJUANA IN FLORIDA

 

Status

 

National medical marijuana activists' efforts in Florida are almost nonexistent. An Orlando-based group, with no funding and a volunteer base led by a stay-at-home mother, has in one year gained only 22,000 of the 687,000 signatures needed to put the issue before voters. Kim Russell, founder of People United for Medical Marijuana, said her group is "just getting started" and is also trying to lobby for a medical marijuana bill in Tallahassee.

 

Strategy

 

Allen St. Pierre, executive director of the National Organization for the Reform of Marijuana Laws, said it takes at least $5 million to collect and verify signatures for a constitutional amendment. In every state where the question of medical marijuana has been put to voters, he said, the campaigns were backed by one of three wealthy men: international investor George Soros, Progressive Insurance's Peter Lewis and Phoenix University's John Sperling. To them, he said, Florida looks like a bad bet, because the state is divided culturally and has segregated media markets that make advertising costly.

 

Outlook

 

Polls find people in the South, including Florida, more skeptical about the benefits of medical marijuana than Americans in the West and North. There is no official support for legalizing pot in Florida. Mary Lynn Mathre, president and co-founder of Patients Out of Time, a Virginia-based organization, noted that the Florida Medical Association issued a statement in 1997 supporting medical marijuana research. But FMA media representative Erin VanSickle said the group's position has since changed. "There were a couple of different policies" on medical marijuana, she explained. "And they were allowed to sunset, so now we have nothing."

 

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