I must take issue. Even with alcohol there is wide person-to-person
variation in the serum levels after ingestion of similar amounts, mostly due
to large variations in volumes of distribution. Thereafter metabolism
dominates, and while there may be zero-order kinetics, the precise rate of
metabolism varies considerably from person to person. None of this matters
to the lawyer however as serum alcohol levels are measured, but I agree that
the law then simplistically assumes that any given serum alcohol level will
produce a similar level of functional impairment in all individuals. However
at least they work from a serum alcohol level, so that all the kinetic
variables of absorption, distribution, metabolism and elimination no longer
matter, and only pharmacodynamic variability is left. So basically the
complex kinetics of other drugs should not prevent them from being policed.
You simply have to work from a serum level, if available, then the kinetics
aren't relevant any more.
Adrian Fogarty
----- Original Message -----
From: "Simon Bell" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, July 15, 2002 7:52 AM
Subject: Re: Drugs and Road Accidents
> I couldnt agree more....... It certainly does for
> alcohol. Mainly due to its zero order kinetics.. hence
> the belief (at least legally) that one level equals
> one response, but other illicit substances have very
> complex kinetics especially ecstasy which has a
> complex hepatic and to a certain extent renal
> metabolism.
>
> For alcohol, amount ingested correlates well with
> serum levels, but for amphetamines there is huge
> variation in kinetics from person to person and unlike
> alcohol it isn't sold in metered doses, hence the
> difficulty in adopting a specific law.
> However, driving without care and attention (due to
> any cause) is still an offence, but I believe carries
> a lower sentance
>
> S Bell
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