3. Umbruch 4.4..2005 - Online Pot

220 F. Barth and M. Rinaldi-Carmona
An increased desire for sweet food (marshmallows) was indeed noted in
subjects after smoking marijuana [4]. Other studies have shown that
∆ 9 -tetrahydrocannabinol (∆ 9 -THC)-induced appetite stimulation was dependent
on the route of administration [5], the dose used [6], the social environment
[7] and the satiety status [8]. Higher appetite stimulation was observed with
the suppository versus oral intake or inhalation, with low-∆ 9 -THC versus
high-∆ 9 -THC cigarettes, in smoking in social groups versus isolated use and
finally in fed versus fasted individuals.
Based on these findings, dronabinol (Marinol ® ), an oral formulation of ∆ 9 -
THC, was approved by the US Food and Drug Administration (FDA) in 1992 for
the treatment of AIDS-related anorexia. This wasting syndrome, which occurs in
about 18% of AIDS patients, is of particular concern in that it may exacerbate
the primary illness, decrease quality of life and also decrease survival.
Several clinical studies involving patients with anorexia related to AIDS,
cancer or Alzheimer’s disease demonstrated the efficacy of dronabinol [9, 10].
In a double-blind, placebo-controlled 6-week study involving 139 patients
with AIDS-related anorexia, dronabinol (5 mg/day) was associated with
increased appetite (38% above baseline versus 8% for placebo), improvement
in mood (+10 versus –2%) and decreased nausea (–20 versus –7%). Body
weight was stable in dronabinol patients, while placebo recipients had a mean
loss of 0.4 kg [11]. These effects were later confirmed in a long-term, openlabel
follow-up study with 94 patients treated for up to 12 months [12].
Dronabinol therapy was generally well tolerated during long-term use, with
most adverse events being associated with the known central effects of
cannabinoids (euphoria, dizziness, confusion). No significant changes in
hematology or blood-chemistry parameters due to the drug were noted.
The use of dronabinol or other cannabinoids, including smoked marijuana,
to treat cancer or AIDS-related anorexia remains, however, controversial due
to the psychotropic properties of these drugs, and also due to the reluctance to
treat immuno-deficient patients with a cannabinoid drug, which may by itself
negatively affect the immune system. This fear may however be unfounded, at
least for dronabinol, if one considers a study that compared the use of dronabinol
and megestrol acetate for the treatment of the HIV wasting syndrome in
which no difference in the CD4 T-lymphocyte count due to the drugs during
the 12-week study was noted [13]. Another study involving 67 patients with
the HIV-1 infection concluded that smoked or oral ∆ 9 -THC did not produce
any harmful effects on viral loads. The findings of this short-term (21-day)
study should however be confirmed in additional long-term trials [14].
In laboratory animals, treatment with ∆ 9 -THC or synthetic cannabinoid agonists
has shown inconsistent effects on food intake [1], with an increase
[15–17], or decrease [18] of food intake, or without any effect [19]. The species,
route of administration and dose used clearly influence the outcome of
the experiments. In particular, the decreased locomotor performance induced
by high doses of cannabinoids may often be responsible for the decreased food
intake observed in the high-dose experiments.