By John Schieszer, Medical Tribune News Service
VANCOUVER, CANADA -- The dual action of a new drug belonging to a
class of compounds called cholinesterase inhibitors may offer a new
way of treating and delaying some of the symptoms of Alzheimer's
disease (AD). The drug, galantamine, inhibits a neurotransmitter in
the brain called acetylcholinesterase and also stimulates nicotine
receptors in the brain, the same receptors stimulated by smoking
tobacco.
``There is data to suggest that stimulating nicotine receptors
produces improvement in learning, memory, attention and
concentration. All these things are very provocative and it raises
the issue that if you were able to stimulate nicotine receptors,
not through smoking but with a drug, it could have a beneficial
effect,'' said Paul R. Solomon, who is a professor of psychology at
Williams College in Williamstown, Mass., and co-director of the
Memory Clinic at the Southwestern Vermont Medical Center. Solomon
presented his results at the Ninth International Congress of the
International Psychogeriatric Association here on Aug. 17.
In clinical trials, galantamine has been shown to produce an
improvement in the Clinician Interview Based Impression of Change
(CIBIC-plus), an overall assessment of patients' performance,
including mental activities and activities of daily living, based
on interviews with patients and feedback from caregivers.
As is common with other drugs in this class, side effects for
patients on galantamine included nausea and vomiting. However, the
side effects were not long-lasting, often subsiding after a week of
treatment.
In a double-blind, placebo-controlled clinical trial involving
636 patients with mild to moderate AD, 423 individuals were
assigned to receive galantamine twice a day for six months and 213
took placebo. Sixty-two percent were female and the mean age was
75.
Study participants were tested using a scale that measures
mental or cognitive abilities called the Alzheimer's Disease
Assessment Scale (ADAS-cog). Among those who completed the study,
patients who took galantamine achieved cognitive scores that were
an average of 3.7 to 3.8 points higher than individuals who
received placebo.
Patients taking galantamine experienced an average improvement
of 1.7 points over their baseline, or beginning, score. In
addition, the cognitive performance of patients taking placebo
declined by an average of 2 points. Initial data suggest that the
first signs of cognitive improvement are experienced in patients as
soon as one week after reaching their target dose.
``The drug is given twice a day and it seems to be well
tolerated, which is quite important,'' said Dr. George Grossberg,
who is a professor of psychiatry at St. Louis University School of
Medicine in St. Louis. ``We now have patients in their second year
of study and it looks very promising.''
Galantamine is now being developed by Janssen Research
Foundation, an affiliate of Johnson & Johnson, under the brand-name
Reminyl, and could be available on the market within 18 months.
``Galantamine is a very interesting drug,'' said Grossberg. ``It
is a derivative of the daffodil plant, which makes it almost like a
natural substance for some people, and that is an attraction.''
Grossberg, who is one of the clinical trial investigators for
galantamine, said that the medication ``stimulates the nicotinic
receptors.'' He added that these are ``very prominent in the brain
and are located throughout the regions of the brain most affected
by Alzheimer's disease.''
