THERAPEUTIC MARIJUANA USE SUPPORTED WHILE THOROUGH PROPOSED STUDY DONE

Advocates for the medical use of marijuana received support recently
from Institute of Medicine (IOM), recommendations that clinical trials
and drug development should proceed. But its acceptance into the
general population of prescribed drugs appears to be years away-if it
happens at all.

The coinvestigators of the report, Marijuana and Medicine: Assessing the
Science Base, said advances in cannabinoid science over the last 16 years
offer opportunities for the development of medical marijuana. The report
summarizes and analyzes what is known about the medical use of marijuana,
emphasizing evidence-based medicine.

The investigators said the data suggest marijuana may help with pain
relief, nausea, and appetite stimulation. Still, there are downsides
to marijuana, said John A. Benson, Jr, MD, coprincipal investigator of
the report and dean and professor of medicine emeritus at Oregon
Health Sciences University School of Medicine in Portland.

"Marijuana's potential as medicine is seriously undermined by the fact
that people smoke it, thereby increasing their chance of cancer, lung
damage, and problems with pregnancies, including low birth weight,"
Benson said. "For that reason, we do not recommend smoking marijuana
for long-term medical use. While we see a future in the development of
chemically defined cannabinoid drugs, we see little future in smoked
marijuana as a medicine." Cannabinoids are the group of compounds
related to 9-tetrahydrocannabinol (THC), the primary psychoactive
ingredient in marijuana.

TWO POINTS OF VIEW

Quick to pick up on the smoking comments was the White House Office of
National Drug Control Policy (ONDCP), whose director, Gen Barry R.
McCaffrey, has been critical of legalizing marijuana for medical use.
In a statement, the ONDCP said it was "delighted that science is the
basis of the discussion of this issue," and said it would carefully
study the recommendations and conclusions of the IOM report. The ONDCP
added, however, "We note in the report's conclusion that 'the future
of cannabinoid drugs lies not in smoked marijuana, but in chemically
defined drugs that act on the cannabinoid systems that are a natural
component of human physiology.' " The IOM report is the result of a
request from the ONDCP in January 1997 to review the scientific
evidence to assess the potential health benefits and risks of
marijuana and its constituent cannabinoids.

[An IOM report says marijuana may have a future in
medicine, but not in a smoked form. Credit: Tony Stone ]

On the other side of the legalization issue is the Marijuana Policy
Project, which said the IOM report presents ample scientific evidence
confirming the benefits of marijuana as medicine and proves McCaffrey
wrong on his statements over the years in opposition to
legalization.

Marijuana was not found effective in several areas in which anecdotal
evidence said otherwise. The report stated that data did not support
using marijuana to treat glaucoma. It noted that smoked marijuana can
reduce some of the eye pressure associated with glaucoma, but only for
a short time, and that its benefit did not outweigh the hazards
associated with regular long-term use. There is also little evidence
for marijuana's potential for treating movement disorders like
Parkinson disease or Huntington disease, although some studies were
presented showing THC reduced, to varying degrees, muscle spasticity
associated with multiple sclerosis.

REPORT RECOMMENDATIONS

The IOM report investigators made six recommendations:

Research should continue into the physiological effects of synthetic
and plant-derived cannabinoids and the natural function of
cannabinoids found in the body. Because different cannabinoids appear
to have different effects, research should include but not be
restricted to effects attributable to THC alone.

Clinical trials of cannabinoid drugs for symptom management should be
conducted with the goal of developing rapid-onset, reliable, and safe
delivery systems.

Psychological effects of cannabinoids, such as anxiety reduction and
sedation, that can influence medical benefits should be evaluated in
clinical trials.

Studies to define the individual health risks of smoking marijuana
should be conducted, particularly among populations in which marijuana
use is prevalent.

Clinical trials of marijuana use for medical purposes should be
conducted under the following limited circumstances: trials should
involve only short-term use (less than 6 months); be conducted in
patients with conditions for which there is reasonable expectation of
efficacy; be approved by institutional review boards; and collect data
about efficacy.

Short-term use of smoked marijuana for patients with debilitating
symptoms (such as intractable pain or vomiting) must meet the
following conditions: failure of all approved medications to provide
relief has been documented; the symptoms can reasonably be expected to
be relieved by rapid-onset cannabinoid drugs; such treatment is
administered under medical supervision in a manner that allows for
assessment of treatment effectiveness; and use involves an oversight
strategy, comparable to an institutional review board process, that
could provide guidance within 24 hours of a submission by a physician
to provide marijuana to a patient for a specified use. Stanley J.
Watson, Jr, MD, PhD, coprincipal investigator and codirector and
research scientist at the Mental Health Research Institute, University
of Michigan, said the goal of medical marijuana clinical trials should
be to develop an inhaler to deliver the drug because capsule or pill
forms take too long to work.

"There are many symptoms for which a quick-acting drug is ideal, such
as pain, nausea, and vomiting," Watson said. "For that reason, we
recommend development of a rapid-onset but nonsmoked delivery system,
such as an inhaler. Something like an inhaler would deliver precise
doses without the health problems associated with smoking."