The Lancet
[Volume 354, Number 9193] 27 November 1999
Science and medicine: Data accrue on "visionary" agent to interrupt addiction
Few
therapies exist for drug addiction, and unfortunately one agent that has shown
promise-- the plant alkaloid ibogaine--is mostly given in unsafe settings by
addict self-help groups, says Deborah Mash (University of Miami, FL, USA). This
means there is a "poverty of clinical data" on the effects of the
preparation. However, Mash now has preliminary findings from almost 100 patients,
and at a series of talks in the UK this month, she presented her results and
called for further research to be top priority.
Ibogaine's
anti-addictive properties have been shown in animals; in human beings, ibogaine
often causes "dream-like states" at treatment doses but is quickly
cleared from the bloodstream. The persistent metabolite noribogaine should act
to raise mood, ward off craving, and help an addict enter long-term therapy
via its actions on both the serotonin transporter and on opiate receptors µ
and (see Lancet 1998; 352: 1298).
After
a single treatment, Mash's team found that Beck Depression Inventory scores
improved significantly (mean 18 vs 4), and remained low for at least a month.
There were also significant decreases in craving scores and in physician-rated
signs of opiate withdrawal. Adverse events seen during the acute treatment phase
were nausea, vomiting, mild tremors, and transient ataxia; initial drops in
heart rate and blood pressure occurred in a few patients, mainly "crack"
cocaine abusers. "Whether the visions are important [for efficacy], I cannot
yet say", notes Mash, "but there are very profound experiences associated
with ibogaine that can be life-transforming".
Despite
these promising results, further drug development is likely to be hindered by
continuing controversies. Ongoing litigation over patent rights between the
University of Miami and Howard Lotsof, the discoverer of ibogaine's anti-addictive
effects, seems likely to deter potential investors. In addition, some experts
have reported cerebellar Purkinje-cell loss in rats treated with high doses
of ibogaine. However, Mash found no such damage at necropsy of one former patient
who died from other causes. Finally, proponents of ibogaine believe that clinical
use of a US schedule-I drug is politically unpalatable in the USA, despite evidence
of the lack of abuse potential.
Kelly Morris