There is growing evidence that there is no relevant difference
in subjective effects between (Schedule III) dronabinol and
cannabis. Thus, it can be expected that the abuse liability
is similar for both agents.
In 1999, the Drug Enforcement Administration (DEA) reclassified
Marinol™ from a "Schedule II" drug to the
less restrictive "Schedule III" category according
to the Controlled Substances Act. This essentially means that
instead of being classified with drugs like morphine, Marinol™
is now classified with more widely used drugs like codeine.
According to the Associated Press of July 3, 1999, Barry McCaffrey,
director of the White House Office of National Drug Control
Policy, said the capsule form of Marinol™ is the "safe
and proper way" to make components of marijuana available
to the public. "This action will make Marinol™,
which is scientifically proven to be safe and effective for
medical use, more widely available," he said. Geoff Sugerman,
a medical marijuana advocate in Oregon, said "Here is
more proof that the properties in marijuana really do work
as medicine." Oregon along with other states approved
the use of marijuana with a doctor's consent, an action McCaffrey
There are not many direct comparisons of the subjective and
medicinal effects of cannabis and dronabinol (THC, Marinol™).
Recent experimental research has shown that the subjective
effects of cannabis and THC are very similar (Wachtel et al.
2002). Authors write:
"There has been controversy about whether the subjective,
behavioral or therapeutic effects of whole plant marijuana
differ from the effects of its primary active ingredient,
Delta(9)-tetrahydrocannabinol (THC). However, few studies
have directly compared the effects of marijuana and THC using
matched doses administered either by the smoked or the oral
Two studies were conducted to compare the subjective effects
of pure THC to whole-plant marijuana containing an equivalent
amount of THC in normal healthy volunteers. In one study the
drugs were administered orally and in the other they were
administered by smoking. (…)
In each study, marijuana users (oral study: n=12, smoking
study: n=13) participated in a double-blind, crossover design
with five experimental conditions: a low and a high dose of
THC-only, a low and a high dose of whole-plant marijuana,
and placebo. In the oral study, the drugs were administered
in brownies, in the smoking study the drugs were smoked. Dependent
measures included the Addiction Research Center Inventory,
the Profile of Mood States, visual analog items, vital signs,
and plasma levels of THC and 11-nor-9-carboxy-THC. (…)
In both the oral study and the smoking study, THC-only and
whole plant marijuana produced similar subjective effects,
with only minor differences.
CONCLUSION: These results support the idea that the psychoactive
effects of marijuana in healthy volunteers are due primarily
to THC" (Wachtel et al. 2002).
Since the abuse potential of a drug is mainly attributed
to its subjective effects it can be assumed that the the abuse
potential of THC and cannabis are quite similar.
Clinical research has also demonstrated similar properties
of THC and cannabis with regard to therapeutic effects. This
is shown in the data from marijuana research programs on the
anti-emetic effects of marijuana in 6 states (Musty &
Rossi 2001, see above), where patients who smoked marijuana
experienced 70-100% relief from nausea and vomiting, and those
who used the THC capsule experienced 76-88% relief. In the
study by Abrams et al. (2002) that investigated the interaction
of smoked cannabis and Marinol™ (THC) with HIV medication,
very similar effects were observed with regard to weight gain.
The participants had been divided into three groups, with
one set smoking marijuana (3.95% THC), another taking oral
dronabinol capsules (3x2.5 mg daily), and a third taking oral
placebo capsules. Researchers found that those using dronabinol
(THC) or marijuana experienced significant increases in caloric
intake and gained an average of 3.5 kg (marijuana group) and
3.2 kg. (THC group) compared to 1.3 kg in the placebo group.
There was no significant difference between marijuana and
THC with regard to side effects and benefits.
Leo Hollister stated in a recent review on the medical use
"Marinol™ or dronabinol, is available for treating
nausea and vomiting associated with cancer chemotherapy and
as an adjunct to weight loss in patients with wasting syndrome
associated with AIDS. Although such approval currently applies
only to orally administered THC, for practical purposes smoked
marijuana should also be expected to be equally effective.
Promising leads, also often fragile, suggest possible uses
for treating chronic pain syndromes, neurological disease
with spasticity and other causes of weight loss. These indications
require more study."
The American public notes that the difference between cannabis
and dronabinol with regard to classification is hypocritical
and political. Journalist Cynthia Cotts commented the reclassification
of Marinol™ from Schedule II to Schedule III in the
Nation on September 20, 1999:
"For more than half a century, the U.S. government has
maintained a hard line on marijuana, denying that the plant
has any medical value at all. But in the period since 1996,
during which voters in several states have approved the medical
use of marijuana and the Institute of Medicine has hailed
the therapeutic effects of THC (one of the cannabinoids found
in the natural plant), the Feds have scrambled to revise their
position. Now, the drug warriors' line goes something like
this: Who needs pot, an illegal substance that burns up your
lungs, when you can take Marinol™, a little white pill
that contains synthetic THC?
The government threw its weight behind Marinol™ this
past July, when the Drug Enforcement Administration moved
the drug into Schedule III, lifting its dangerous stigma and
making it easier for doctors to prescribe. While drug czar
Barry McCaffrey insisted the move was based on "pure
science," a review of the players involved suggests that
the rise of Marinol™ is more the result of politics
and profiteering" (Cotts 1999).
Abrams DI, et al. Short-Term Effects of Cannabinoids In Patients
With HIV Infection. J Cannabis Ther 2002;2(2):92-93.
Cotts C. Marijuana made easy. The Nation, September 20, 1999.
Hollister L. Marijuana (cannabis) as medicine. J Cannabis
Musty RE, Rossi R. Effects of smoked cannabis and oral ?9-tetrahydrocannabinol
on nausea and emesis after cancer chemotherapy: a review of
state clinical trials. J Cannabis Ther 2001;1(1):29-42.
Wachtel SR, ElSohly MA, Ross SA, Ambre J, De Wit H. Comparison
of the subjective effects of Delta(9)-tetrahydrocannabinol
and marijuana in humans. Psychopharmacology (Berl) 2002;161(4):331-9.