748 P. R o b s o n
4.5
Drug Withdrawal Treatments
In contrast to contemporary concerns about the addictive potential of cannabis,
the drug was used in the nineteenth century in the treatment of dependencies on
various other substances including alcohol, cocaine, chloral hydrate and morphine.
Anyone who discusses the problems of opiate withdrawal with a modern heroin
addictislikelytobetoldofthebeneficialeffectsofmarijuanainallayingwithdrawal
symptoms, and this anecdotal evidence is given some scientific credibility by
a number of studies in animals (Hine et al. 1975; Bhargava 1976; Chesher and
Jackson 1985). In animal pain models THC inhibits the development of opioid
tolerance and physical dependence (Chichewicz and Welch 2003). At the time of
writing, the efficacy of a combination of THC and CBD (Sativex) in alleviating
the opioid withdrawal syndrome is being explored in a double-blind, placebo-
controlled study.
There are anecdotal reports that cannabis is useful in countering both the
withdrawal symptoms (Labigalini et al. 1999) and paranoia and weight loss (Dreher
2002) associated with smoking crack cocaine.
See above (Sect. 2.6) for the promising preliminary outcome of a trial evaluating
the CB 1 receptor antagonist rimonabant as an aid to abstaining from tobacco
smoking.
4.6
Migraine
This is a common disorder in which attacks, sometimes preceded by an aura,
consist of intense headache along with nausea and sensitivity to light and sound
lasting anywhere from a few hours to several days. In historical times, cannabis
was widely used in the treatment of headache, and there are numerous modern
anecdotes (Grinspoon and Bakalar 1993). The pathology underlying the disorder
remains controversial, but serotonergic, dopaminergic, inflammatory and brain
stem mechanisms have been implicated.
In a detailed review, Russo (2001) considers how cannabinoids may impact on
these systems and makes a compelling case for initiating controlled clinical trials.
4.7
Intractable Breathlessness
A number of lung diseases (e.g. chronic bronchitis and emphysema) are capable
of producing shortness of breath that is often extremely distressing to the patient.
Many of these conditions are irreversible, so it becomes necessary to target the
symptom itself. The sensation of breathlessness is a complicated phenomenon that
seems to depend upon central processing through respiratory and non-respiratory
mechanisms (Guz 1996). Ideally, a treatment would relieve the unpleasant sensa-