Are there any medical facts for marijuana?

Charlene DeGidio never smoked marijuana in the 1960s, or afterward. But
a year ago, after medications failed to relieve the pain in her legs and
feet, a doctor suggested that the Adna, Wash., retiree try the drug.

Ms. DeGidio, 69 years old, bought candy with marijuana mixed in. It
worked in easing her neuropathic pain, for which doctors haven't been
able to pinpoint a cause, she says. Now, Ms. DeGidio, who had previously
tried without success other drugs including Neurontin and lidocaine
patches, nibbles marijuana-laced peppermint bars before sleep, and keeps
a bag in her refrigerator that she's warned her grandchildren to avoid.

"It's not like you're out smoking pot for enjoyment or to get high,"
says the former social worker, who won't take the drug during the day
because she doesn't want to feel disoriented. "It's a medicine."

For many patients like Ms. DeGidio, it's getting easier to access
marijuana for medical use. The U.S. Department of Justice has said it
will not generally prosecute ill people under doctors' care whose use of
the drug complies with state rules. New Jersey will become the 14th
state to allow therapeutic use of marijuana, and the number is likely to
grow. Illinois and New York, among others, are considering new laws.

As the legal landscape for patients clears somewhat, the medical one
remains confusing, largely because of limited scientific studies. A
recent American Medical Association review found fewer than 20
randomized, controlled clinical trials of smoked marijuana for all
possible uses. These involved around 300 people in all—well short of
the evidence typically required for a pharmaceutical to be marketed in
the U.S.

Doctors say the studies that have been done suggest marijuana can
benefit patients in the areas of managing neuropathic pain, which is
caused by certain types of nerve injury, and in bolstering appetite and
treating nausea, for instance in cancer patients undergoing
chemotherapy. "The evidence is mounting" for those uses, says Igor
Grant, director of the Center for Medicinal Cannabis Research at the
University of California, San Diego.

But in a range of other conditions for which marijuana has been
considered, such as epilepsy and immune diseases like lupus, there's
scant and inconclusive research to show the drug's effectiveness.
Marijuana also has been tied to side effects including a racing heart
and short-term memory loss and, in at least a few cases, anxiety and
psychotic experiences such as hallucinations. The Food and Drug
Administration doesn't regulate marijuana, so the quality and potency of
the product available in medical-marijuana dispensaries can vary.

Though states have been legalizing medical use of marijuana since 1996,
when California passed a ballot initiative, the idea remains
controversial. Opponents say such laws can open a door to wider
cultivation and use of the drug by people without serious medical
conditions. That concern is heightened, they say, when broadly written
statutes, such as California's, allow wide leeway for doctors to decide
when to write marijuana recommendations.

But advocates of medical-marijuana laws say certain seriously ill
patients can benefit from the drug and should be able to access it with
a doctor's permission. They argue that some patients may get better
results from marijuana than from available prescription drugs.

Glenn Osaki, 51, a technology consultant from Pleasanton, Calif., says
he smokes marijuana to counter nausea and pain. Diagnosed in 2005 with
advanced colon cancer, he has had his entire colon removed, creating
digestive problems, and suffers neuropathic pain in his hands and feet
from a chemotherapy drug. He says smoking marijuana was more effective
and faster than prescription drugs he tried, including one that is a
synthetic version of marijuana's most active ingredient, known as THC.

The relatively limited research supporting medical marijuana poses
practical challenges for doctors and patients who want to consider it as
a therapeutic option. It's often unclear when, or whether, it might work
better than traditional drugs for particular people. Unlike prescription
drugs it comes with no established dosing regimen.

"I don't know what to recommend to patients about what to use, how much
to use, where to get it," says Scott Fishman, chief of pain medicine at
the University of California, Davis medical school, who says he rarely
writes marijuana recommendations, typically only at a patient's request.

Researchers say it's difficult to get funding and federal approval for
marijuana research. In November, the AMA urged the federal government to
review marijuana's position in the most-restricted category of drugs, so
it could be studied more easily.

Gregory T. Carter, a University of Washington professor of
rehabilitation medicine, says he's developed his own procedures for
recommending marijuana, which he does for some patients with serious
neuromuscular conditions such as amyotrophic lateral sclerosis, or Lou
Gehrig's disease, to treat pain and other symptoms. He typically urges
those who haven't tried it before to start with a few puffs using a
vaporizer, which heats the marijuana to release its active chemicals,
then wait 10 minutes. He warns them to have family nearby and to avoid
driving, and he checks back with them after a few days. Many are
"surprised at how mild" the drug's psychotropic effects are, he says.

States' rules on growing and dispensing medical marijuana vary. Some
states license specialized dispensaries. These can range from small
storefronts to bigger operations that feel more like pharmacies.
Typically, they have security procedures to limit walk-in visitors.

At least a few dispensaries say they inspect their suppliers and use
labs to check the potency of their product, though states don't
generally require such measures. "It's difficult to understand how we
can call it medicine if we don't know what's in it," says Stephen
DeAngelo, executive director of the Harborside Health Center, a
medical-marijuana dispensary in Oakland, Calif.

Some of the strongest research results support the idea of using
marijuana to relieve neuropathic pain. For example, a trial of 50 AIDS
patients published in the journal Neurology in 2007 found that 52% of
those who smoked marijuana reported a 30% or greater reduction in pain.
Just 24% of those who got placebo cigarettes reported the same lessening
of pain.

Marijuana has also been shown to affect nausea and appetite. The AMA
review said three controlled studies with 43 total participants showed a
"modest" anti-nausea effect of smoked marijuana in cancer patients
undergoing chemotherapy. Studies of HIV-positive patients have suggested
that smoked marijuana can improve appetite and trigger weight gain.

Donald Abrams, a doctor and professor at the University of California,
San Francisco who has studied marijuana, says he recommends it to some
cancer patients, including those who haven't found standard anti-nausea
drugs effective and some with loss of appetite.

Side effects can be a problem for some people. Thea Sagen, 62, an
advanced neuroendocrine cancer patient in Seaside, Calif., says she
expected something like a pharmacy when she went to a marijuana
dispensary mentioned by her oncologist. She says she was disappointed to
find that the staffers couldn't say which of the products, with names
like Pot 'o Gold and Blockbuster, might boost her flagging appetite or
soothe her anxiety. "They said, 'it's trial and error,' "she says. "I
was in there flying blind, looking at all this stuff."

Ms. Sagen says she bought several items and tried one-eighth teaspoon of
marijuana-infused honey. After a few hours, she was hallucinating , too
dizzy and confused to dress herself for a doctor's appointment. Then
came vomiting far worse than her stomach upset before she took the drug.
When she reported the side effects to her oncologist's nurse and her
primary-care physician, she got no guidance. She doesn't take the drug
now. But with advice from a nutritionist, her appetite and food intake
have improved, she says.

Other marijuana users may experience the well-known reduction in ability
to concentrate. At least a few users suffer troubling short-term
psychiatric side effects, which can include anxiety and panic. More
controversially, an analysis published in the journal Lancet in 2007
tied marijuana use to a higher rate of psychotic conditions such as
schizophrenia. But the analysis noted that such a link doesn't
necessarily show marijuana is a cause of the conditions.

Long-term marijuana use can lead to physical dependence, though it is
not as addictive as nicotine or alcohol, says Margaret Haney, a
professor at Columbia University's medical school. Smoked marijuana may
also risk lung irritation, but a large 2006 study, published in Cancer
Epidemiology, Biomarkers & Prevention, found no tie to lung cancer.