|
• Pharmacy practice
• Health economics
• Dispensing errors
• Controlled drugs
• Ethics
• Adverse events
• Regulation
• Fitness to practise
• The Society (2)
• Retention fees (5)
• Pharmacy politicians
• The Journal (2)
Letters to the Editor
|
Adverse events
Article overlooks new evidence regarding side effects of tetrabenazine
From Dr P. Nichols
I am writing in response to the article by Elizabeth Bevan and Carol Paton, “What
evidence there is for the treatment of Huntingdon’s disease” (PJ,
25 November, pp641–642). In this article the authors mention the
use of tetrabenazine (Xenazine TM 25) as an effective treatment for chorea
in Huntingdon’s disease but quote rather old publications with regard
to the side effect profile of this drug.
Unfortunately, they appear to have overlooked the recent phase III, randomised,
placebo-controlled trial published earlier this year by the Huntingdon
Study Group in the US (Neurology 2006;66:366–72) which concluded
that “tetrabenazine, at adjusted dosages of up to 100mg per day,
effectively lessens chorea in … patients with Huntingdon disease” with
an impressive statistical significance (P>0.0001). In this study the
starting dose was 12.5mg and this dose was increased weekly in 12.5mg increments,
a “start low, go slow approach” to dosing up to a maximum of
100mg daily in divided doses. Doses were optimised according to an individual
patient’s response. With this approach, side effects were minimised
and, indeed, once patients had been stabilised on their optimum dose, there
were no significant differences in the number of adverse events between
the tetrabenazine- and the placebo-treated patients.
We would maintain that current gold standard evidence supports that tetrabenazine
is an effective drug for the treatment of chorea in Huntingdon’s
disease and that with careful dose titration side effects can be kept to
an acceptable minimum.
Philip Nichols
Medical Director,
Cambridge Laboratories Ltd |
The
Pharmaceutical Journal