Examination of Witnesses (Questions 300
- 319)
TUESDAY 27 OCTOBER 2009
PROFESSOR DAVID
NUTT AND
DR FIONA
MEASHAM
Q300 Mr Winnick: Because Parliament
must decide one way or the other obviously. Do you agree with
what your colleague has just said, Dr Measham?
Dr Measham: I do, yes.
Q301 Tom Brake: I wanted to ask whether
you thought that there was any scope for increasing the range
of products that you are looking at because of course cannabis
seeds are not actually illegal, which is a bit strange given how
easy it is to grow cannabis here.
Professor Nutt: We are looking
at that, I should say—the issue about substances which are
currently in themselves are not active psychotropids but which
could lead to them is an important one and we obviously do have
some controls over that in terms of precursors of drugs like stimulants;
so we do have controls over the precursors. Whether you can bring
seeds into the precursors' legislation or some similar legislation
to that is something we are looking at. It is an interesting approach
but it is not high on our list of priorities.
Q302 Tom Brake: It is difficult though,
is it not, because I think they can be used as bird seed?
Professor Nutt: Yes, indeed they
can, and in themselves they are not in any sense harmful.
Q303 Mrs Cryer: If cocaine is not
physically addictive—that is what we have been told—
Professor Nutt: That is wrong,
by the way.
Q304 Mr Streeter: Can you unpack
that for us, please?
Professor Nutt: Cocaine causes
addiction; addiction is a physical process of changing the brain
and there are thousands of papers showing that cocaine use changes
the brain, often in a way that makes it very, very difficult for
people to give up using cocaine and that is why success rates,
particularly for crack cocaine, are not as good as they are for
other forms of addictive drugs because it does change the brain.
It changes the body as well but it does not produce the same kind
of physiological withdrawal with drugs like opiates or alcohol,
but unquestionably it produces a physical dependence and physical
changes to the brain.
Q305 Mrs Cryer: So you are happy
that it should remain a class A classification?
Professor Nutt: Cocaine is undoubtedly
a class A drug—I do not think there is any doubt about that.
Cocaine powder is less harmful than crack cocaine; within the
scale of drugs in class A crack and heroin are at the top. We
thought that Ecstasy should be B, so if you took Ecstasy out cocaine
powder would be towards the bottom, but I think it is still above
that threshold. That would be my view of what the Council would
say.
Q306 Mrs Cryer: But you will not
go so far as to say that crack and powder should be classified
differently?
Professor Nutt: I would not.
Q307 Mrs Cryer: They should remain
as A?
Professor Nutt: I think that A
is the right place for cocaine, given the number of deaths and
the degree of dependency it produces, and the difficulty of getting
off cocaine. It is considerably more addictive than some other
drugs of class A like MDMA, Ecstasy, like the psychedelics. So
I am comfortable; but I am speaking as myself. The Committee has
not been asked to review the classification of cocaine powder
but I would be surprised if it would disagree with me, to be honest.
The evidence base is always being reviewed but nobody has ever
said it should be out of that.
Q308 Mr Streeter: Do you want to
comment, Dr Measham?
Dr Measham: In some ways it makes
sense to at least approach the two drugs differently, crack and
cocaine, because they have quite different effects and the people
who take the two drugs are quite different. So I think there is
a reason to separate them in terms of scientific analysis and
consideration even if the end result is that they are both class
A.
Q309 Mr Clappison: You mentioned
that in addition to the changes to the brain which cocaine brings
about that there are bodily changes; could you tell us what they
might be?
Professor Nutt: Cocaine is a problem.
One of the reasons that people die of cocaine is through cardiac
complications and cocaine is a profound cardiac stimulant. It
can also cause irregularities of the heart; so a lot of young
men who use cocaine die because of the cardiac consequences. Those
are exaggerated by the co-use of cocaine with alcohol and the
reason for that is that there is another drug made in the body
as alcohol fuses with cocaine, to produce a longer acting cardiac
stimulant called cocaethylene and that is probably the reason
why it is so cardiotoxic. But also cocaine is associated with
high blood pressure.
Q310 Mr Clappison: So it is a loss
of life expectancy as a result of using cocaine?
Professor Nutt: Yes. We see 200
to 300 deaths a year as a consequence of using cocaine, which
is quite a lot.
Q311 Mr Clappison: Are the changes
to the brain permanent or do they stop or reverse if someone stops
taking cocaine?
Professor Nutt: That is a really
interesting question. No one is sure about whether they are reversible;
they are certainly very long lasting. So you can do brain imaging
studies of cocaine users and find quite marked abnormalities particularly
of what we call executive function—those functions in the
brain that allow people to make the right kind of judgments and
assessments about what they are doing with their life. Those get
impaired by cocaine because it does target the frontal part of
the brain, which is where those decisions are made. That is one
of the reasons why it can be very difficult to engage heavy cocaine
and crack users in treatment because they have lost that capacity
for planning behaviour in a way to maximise the benefits of treatment.
Q312 Mr Clappison: That is the same
for powdered cocaine and crack cocaine? Crack cocaine might be
worse?
Professor Nutt: Crack will be
worse. The difference between crack and powder is just the way
of delivery. When it gets into the brain it is all cocaine, but
crack gets in the brain faster—unless you take powder intravenously.
But assuming you smoke crack and you snort powder then you get
a bigger rise of cocaine in the brain with crack and that rising
level of cocaine is what produces the maximal changes in the brain,
and those changes are both the maximal pleasure—hence people
get more addicted to it—but they may also be the causation
of damage to the brain. There is a little bit of evidence—I
do not say categorically it is true—there is a suggestion
that crack will actually kill cells in the brain and actually
knock off part of the brain and destroy it—at least to some
extent.
Q313 Tom Brake: I wanted to very
briefly come back to the issue of classification. Does it make
any sense to have a rigid A, B, C categorisation? Could it be
A to F in terms of better grouping of drugs?
Professor Nutt: Some countries
do that; some countries do not have a classification and they
just say opiates, stimulants, benzos. You can do it that way.
I quite like the A, B, C classification—I can see there
are merits in it if it is correct because I think it directs policing
in a fairly simple way. But it also could have huge value in terms
of education and that is why we have been very keen to get it
right because you can then direct people away from the most harmful
drugs by getting them to really understand that class A drugs
are the most harmful, and that is why there is this discussion.
If you get classification right I think there is a huge utility
for education and we are missing that opportunity at present.
Q314 Tom Brake: Dr Measham, could
we come on to a slightly different subject? I believe your focus
is on emerging drugs. We have heard from other witnesses that
they are worried about the growth in crystal meth; is that something
that you would echo in terms of concerns?
Dr Measham: My research looks
at changing patterns and prevalence of use amongst young people
in the general population. Most of the people that I conduct research
with are in touch with treatment services and in the general population
crystal meth is not rising at a rapid rate—I would say that
very, very few people I have spoken to have ever even tried it
or had access to it. There are other drugs which I think are becoming
increasingly popular with young people: for example, Ketamine
would be one. Just in the past year or two I have been conducting
research on Ketamine and that has taken off quite rapidly in terms
of popularity.
Q315 Tom Brake: That is a class C
drug and you are happy that that is the right classification for
it?
Dr Measham: It is a short acting
dissociative anaesthetic. At the moment it is much cheaper than
cocaine and I think we might be seeing some displacement because
the purity of cocaine has gone down. The price has gone down but
the actual cocaine content has gone down; so I think we are seeing
a little bit of a displacement for Ketamine.
Q316 Tom Brake: That is the drug
used by vets, is it, for putting out horses?
Dr Measham: It is phrased as an
anaesthetic for horses, yes.
Q317 Tom Brake: Would your research
tell you where it is coming from? Is it coming from veterinary
sources or is it being produced in backstreet laboratories?
Dr Measham: I think partly imported
from the Indian sub-continent, but I think there are various possibilities.
Professor Nutt: Let me talk to
that because we brought Ketamine into the Act about four years
ago. We did it because of evidence of huge importation, particularly
from India—vast amounts coming in which we could not interdict
because it was not controlled. There was relatively little evidence
of diversion from a vet source or other hospitals—it is
also used in hospital practice as an anaesthetic for children
particularly—mostly it was importation. So we do not know
whether making it class C actually has a significant impact on
importation yet but what we are seeing is a very worrying, persistent
increase in use with some very unpleasant consequences, particularly
bladder spasms, bladder pain and leading to bladder dysfunction
and we are quite worried that there may be some huge problem with
long term bladder dysfunction developing in these young people
using Ketamine. So to get back to your question, I am quite keen
that we need to review Ketamine because it may be that class C
is not the right class and it may be that we have to consider,
as our knowledge of the harm grows, it might be that we decide
that it should be higher than class C.
Q318 Tom Brake: Are there any other
drugs that you are worried about? Presumably the chemical combinations
are infinite and someone can design another drug in a laboratory
at any moment.
Professor Nutt: In theory yes,
but in practice that is not so straightforward. What we are seeing
now is that there are two areas of particular concern to us which
we are working hard on. One relates to the sedative drug, GBL,
and for butanedione, which we have recommended controlling along
with GHB now because of their acute toxicity, particularly if
you take them when you are drunk. Then there are the synthetic
cannabinoids like "Spice". There we know of about 30
potential synthetic cannabinoids which could be sold in smoking
mixtures and we are trying to be the first country in the world
to have what we call generic legislation. We are looking to see
whether we can produce a law where we cover all those different
chemical entities. Eventually people may well work their way around
it but it is not so straightforward because if we cover everything
that is known we do need a very sophisticated level of chemistry
to find new figures. It is quite easy to go to the textbooks and
say, "That is not covered; we will sell that," but once
you go beyond what is known then it is a different level and it
makes it much harder.
Q319 Mr Streeter: On this subject,
Professor Nutter, new patterns emerging and new drugs and so on
being out there, the Home Secretary wrote in March 2009 talking
about a more robust early warning system. Is that now in place?
Professor Nutt: We are working
on it, yes; we have a working group set up to look at this and
I will be hearing a report from them when we have our Council
meeting in about three weeks' time. We have good links with the
European early warning network as well; so we are looking to see
if there is anything we can do to improve it nationally; so we
will take that forward, but I cannot yet tell you what their recommendations
are.
Dr Measham: Could I add a third
category to the Ketamine and synthetic cannabinoids, which is
the methcathinones? Because at the moment Ecstasy tablets have
so little Ecstasy in, and cocaine, when people buy it on the street,
has so little cocaine in, there is a trend towards people buying
drugs on the Internet which are currently legal, methcathinones,
and there is a shift away from illegal towards the legal in relation
to that which I have noticed recently in the research.
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