Dear Mike,
We have compromised & agreed with our Psyche colleagues in Cambridge that
we will send off a serum valproate assay if eg they contact me directly,
but not otherwise. (At about one a month, this would be rather few for
assay here.)
After Mike Guillain kindly sent me helpful info during last summer's
mailbase exposure of this topic, I was able to persuade the local Director
of Psyche, but NOT their Professor, to accept a similar view of Bowden's
paper to your comments.
As you imply, the impressive evidence of the clinical response to treatment
has totally dwarfed the limitations in methodology & statistics of Bowden's
assays. Result - that paper is being quoted almost as a gold standard now.
Best wishes,
Les
MIKE HALLWORTH WROTE:-
>Sue
>
>You're right to be skeptical, but this issue is getting very difficult. As
>you point out, the only decent study on relating valproate concentration to
>response in mania (Bowden et al. Am J Psych 1996 15: 765-70) found that
>patients with bipolar disorder who have valproate concentrations between 45
>mg/L and 100-125 mg/L are much more likely to have efficacious and
>well-tolerated responses than patients with concentrations outside this
>range.
>However, the study did not address the crucial question of whether plasma
>level is a better predictor than dose is. It's important also to note that
>the work is based on fasting trough valproate concentrations.
>
>Unfortunately, the subtleties of the message have been missed by people who
>write guidelines, and both the American and Canadian guidelines for the
ETC ETC ETC
Dr Les Culank,
Consultant Chemical Pathologist
Box 232 Addenbrooke's Hospital Cambridge UK CB2 2QR
01223 - 217153 fax 216862
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