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of CannabisTherapeutic
Uses of Cannabisby
The House of Lords, Science and Technology Committee
14 March 2001
CONTENTS
REPORT
Appendix
1: Members of the Select Committee Appendix
2: Witnesses
By
the Select Committee appointed to consider Science and Technology. ORDERED
TO REPORT
THERAPEUTIC
USES OF CANNABIS BACKGROUND
1.
In this short Inquiry we wanted to follow up issues relating to our earlier Inquiry,
Cannabis: The Scientific and Medical Evidence (November 1998).[1]
In that Report, we recommended that doctors should be permitted to prescribe an
appropriate preparation of cannabis if they saw fit, albeit as an unlicensed medicine
and on a named-patient basis. In a departure from the usual convention, the Government
rejected this recommendation on the morning the Report was published. The Government's
written reply was no more encouraging.[2] In March 1999,
therefore, the Committee wrote: "we
regret that the mind of the Government appears to be closed on this issue, and
hope that the results of new research now under way may cause them to revisit
our recommendations at an early date."[3] 2.
This Inquiry was convened to examine the current state of research into the therapeutic
uses of cannabis, the roles of the Home Office and the Medicines Control Agency
in the licensing of cannabis-based medicines, and more recent issues relating
to the prosecution of therapeutic cannabis users. 3.
One hearing was held. We took evidence from: Charles Clarke MP, Minister of State
in the Home Office; Dr Brian Davis, from the Medicines Control Agency Licensing
Division; and Ms Judy Sanderson from the Health Services Directorate in the Department
of Health. The transcript of that session is appended to this Report.
4. In addition
to receiving written memoranda by these witnesses, we also solicited written material
from the Alliance for Cannabis Therapeutics (ACT); G. W. Pharmaceuticals,
a private company engaged in the development of cannabis-based medicines; and
the Medical Research Council. These too are appended to this Report. We extend
our thanks to those who took the time to contribute evidence to this Inquiry.
5.
In 1998, we recommended that cannabis and its derivatives should continue to be
controlled drugs. We still hold that view. We consider that any debate on the
legalisation of cannabis and cannabis-based medicines should maintain a clear
distinction between therapeutic and non-therapeutic use. This report is concerned
solely with the therapeutic use of cannabis and cannabis-based medicines.
THE
STATE OF RESEARCH 6.
The Medical Research Council (MRC) recently approved awards totalling over £1.5
million involving two new trials:
(i) Dr John Zajicek, a neurologist at Derriford Hospital, Plymouth, is conducting
a three year study to assess the efficacy of cannabis extract and tetrahydrocannabinol
(THC) in the treatment of spasticity in people suffering from multiple sclerosis.
The title of the trial is "Cannabinoids in Multiple Sclerosis" ("CAMS");
(ii)
Dr Anita Holdcroft at Hammersmith Hospital, Imperial College School of Medicine,
London, is conducting a two year study to assess the efficacy of cannabis extract
and THC as postoperative analgesics. This trial is entitled "A clinical trial
as proof of principle of the analgesic effectiveness of cannabinoids on postoperative
pain" ("CANPOP"). In
addition, the MRC has awarded over £600,000 to fund basic cannabinoid research.[4]
7.
Progress on the implementation of these trials, however, has not been rapid. Dr
Zajicek's trial has only just started to recruit its projected 600 patients, while
the precise operational details of Dr Holdcroft's trial have yet to be finalised.
8.
The two MRC-funded trials are "proof of principle" trials, rather than
trials of a specific medical preparation. While we welcome good quality research
into the therapeutic effects of cannabis, we are concerned that the timescale
for developing usable therapeutic preparations from these trials is extremely
long. 9.
A private company, however, G. W. Pharmaceuticals, has also conducted extensive
research into the development of a cannabis-based medicine. From written evidence
submitted to us, we are pleased to note that the company is making some progress,
both in establishing the efficacy of a cannabis-based medicine in the treatment
of patients with multiple sclerosis as well as spinal cord injuries, and in developing
suitable medical preparations. It is planning to move to Phase III clinical trials
shortly.[5] 10.
G. W. Pharmaceuticals has also made progress in improving the mode of delivery
of cannabis-based medicines. It has developed a sub-lingual spray which seems
to avoid the dangers inherent in smoking herbal cannabis, and the difficulties
of controlling the dose during oral administration.[6]
THE
GOVERNMENT POSITION ON CANNABIS-BASED MEDICINES 11.
We are pleased to note that the Government now display a more encouraging attitude
towards the licensing of therapeutic preparations of cannabis than we have previously
detected. The Minister was quick to deny suggestions that the Government were
hiding behind scientific opinion. Should the quality, safety and efficacy of an
appropriate preparation of cannabis be established, we were assured that the Government
would reschedule cannabis from Schedule 1 to Schedule 2 of the Misuse of Drugs
Regulations 1985.[7] In effect, the Minister assured us that
once a safe, effective, cannabis-based medicine had been licensed by the Medicines
Control Agency, the Government would actively co-operate in permitting it to be
prescribed. 12.
The Government's policy has not in fact changed since their response to our Cannabis
report in 1998. Up until now we have sensed that the authorities have been dragging
their feet, at least partly because they may have feared that permitting therapeutic
preparations of cannabis to be prescribed would be interpreted by the public as
a move towards allowing recreational use. The Minister told us, however, that:
"there
is now a much sharper awareness of the distinction between medicinal use of cannabis
and recreational use of cannabis in the public debate" (Q. 49).
We
are pleased, too, that the Minister now shares our view that, were the law relaxed
on the therapeutic use of cannabis, the Government's hand in suppressing illegal,
recreational use would be strengthened (Q. 51). 13.
In our original inquiry we were told that research into cannabis was hampered
by the "stigma" attached to cannabis and the burden of obtaining Home
Office research licences.[8] Since that Report, the Royal
Pharmaceutical Society has produced protocols for the conduct of the two MRC-funded
"proof of principle" trials of cannabis. In addition, both Dr Zajicek
and G. W. Pharmaceuticals have told us that the Home Office has been helpful to
them in planning their trials. While we stand by our original recommendation that
cannabis should be rescheduled in order to facilitate research,[9]
we are at least encouraged that the Home Office is co-operating well with researchers
within the current regulations. THERAPEUTIC
CANNABIS USERS AND THE LAW 14.
There have recently been a number of high-profile cases involving the prosecution
of therapeutic users of cannabis: the memorandum by the Alliance for Cannabis
Therapeutics (ACT) (p. 26) has highlighted a number of them. The decision
to prosecute, taken by the Crown Prosecution Service (CPS), does not seem to be
consistent from region to region. Moreover, in some cases, juries have acquitted
therapeutic users who do not deny the offence, but plead therapeutic use in mitigation;
in other cases, defendants have been found guilty and sentenced. 15.
The Minister sought to deny that therapeutic cannabis users were subject to "postcode
prosecuting". He stressed that the number of therapeutic users who were prosecuted
was extremely small when compared to the total of 89,000 cases involving cannabis
in 1998.[10] He also said that the variation in the outcome
of cases for therapeutic users was less than for other offences, including the
recreational use of cannabis. The number of cases of therapeutic users of cannabis
being prosecuted is certainly small. Exact statistics are difficult to obtain,
however, as the Home Office does not maintain a record of those prosecuted for
cannabis use who claim therapeutic use as a defence. 16.
The Minister further said that he had no intention of changing the current position,
whereby the decision whether or not to prosecute for cannabis-related offences
is made locally by the Police and the CPS. He did, however, emphasise that discretion
could be exercised at three levels of the prosecution process: by the Police;
by the CPS; and by the Courts. Guidelines issued by the Association of Chief Police
Officers (ACPO) on dealing with cannabis offences specifically refer to therapeutic
use, and recommend that a caution is usually appropriate; the CPS guidelines require
that any prosecution should be in the public interest; and the Court of Appeal
issues guidance that the possession of small amounts of cannabis for personal
use can often be met by a fine. 17.
We accept that recreational users, if arrested, may claim to be therapeutic users.
We have no wish to dissuade the Police and the CPS from prosecuting those whom
they believe to be making such claims falsely. 18.
We recognise that the Government do not consider it appropriate to override the
authority of the Police and the CPS. We also understand that the present system
allows discretion to be used at many levels. We consider, however, that the acquittal
of cannabis users by juries on compassionate grounds brings the law into disrepute.
In the absence of a viable alternative medicine, moreover, and though we would
not encourage smoking of cannabis,[11] we consider it undesirable
to prosecute genuine therapeutic users of cannabis who possess or grow cannabis
for their own use. This unsatisfactory situation underlines the need to legalise
cannabis preparations for therapeutic use. THE
MEDICINES CONTROL AGENCY AND THE TOXICITY OF CANNABIDIOL 19.
While we are encouraged at the recent change of attitude shown by the Home Office,
we consider that decisions taken by the Medicines Control Agency (MCA) appear
to be inconsistent. We did not feel that the MCA adequately answered our questions
about the proposed use of cannabidiol in cannabis-based medicines. We were also
disappointed that the witness from the MCA seemed unprepared even to consider
discussing the basis on which the MCA's decisions were made. 20.
Raw cannabis (cannabis sativa) contains more than 60 cannabinoids and more than
400 chemical compounds. The two most abundant cannabinoids, which are currently
subject to the most detailed investigation, are delta-9-tetrahydrocannabinol (THC)
and cannabidiol (CBD). Both these cannabinoids are present in raw cannabis. They
are also both present in the cannabis oil capsules ("Cannador") which
Dr Zajicek is proposing to use in his CAMS trial,[12] and
in the cannabis extracts used by G. W. Pharmaceuticals. 21.
THC has long been established in the pharmacopoeia. The MCA are satisfied that
there is adequate information on the toxicological profile of THC to justify long-term
exposure to THC in the CAMS trial (p. 31). An oral preparation of synthetic THC
in sesame oil ("Marinol") can already be prescribed by doctors.[13]
22.
By contrast, the MCA are unhappy with the toxicology data on CBD. They said that
there is some evidence that CBD inhibits spermatogenesis in animals, and that
overall there is a lack of adequate data. The MCA have therefore not permitted
Dr Zajicek to proceed with his trial of Cannador (cannabis oil) capsules beyond
15 weeks. Moreover, the MCA's decision to insist on further toxicology data on
CBD could delay the production of a cannabis-based medicine by G. W. Pharmaceuticals
by as much as 2 to 3 years. Were the MCA not to require further extensive toxicological
studies on CBD, G. W. Pharmaceuticals claim that they could have a cannabis-based
prescription medicine available for patients in 2003. 23.
We note that, according to G. W. Pharmaceuticals, the Canadian regulatory authorities
have stated that they do not require additional animal toxicology studies for
CBD. We put this to the MCA, who refused to comment (Q. 5); we found this
refusal highly unsatisfactory. 24.
We consider that the decision of the MCA is flawed for three reasons which are
discussed in turn below:
(a) the MCA persist in treating CBD and cannabis oil as "new medicines",[14]
though cannabis oil, which contains both CBD and THC, has a long history of human
use and appeared in the British Pharmacopoeia Codex until 1948;[15]
(b)
the studies which the MCA took to indicate an inhibition of spermatogenesis involved
doses of CBD at least 100 times higher than the doses contemplated by either Dr
Zajicek or G. W. Pharmaceuticals; and (c)
the potential side-effects of CBD about which the MCA are concerned might be regarded
as trivial by those patients, such as those suffering from multiple sclerosis,
who stand to benefit from medicines incorporating CBD. These concerns could be
dealt with by issuing a warning to physicians who prescribe cannabis-based medicines.
The attitude of the MCA in not allowing patients to make their own decisions could
be regarded as overprotective. 25.
Both the MCA and the Home Office persist in treating cannabis-based medicines
as new medicines. Cannabis, however, has a history of medical use in man stretching
back hundreds of years. For much of the nineteenth century and the first half
of the twentieth century, moreover, it was administered in Britain as a tincture
(cannabis oil in alcohol): thus the oral administration of cannabis extracts which
contain significant quantities of CBD has a long history of medicinal use. In
choosing to ignore the long history of safe therapeutic cannabis use, and in classifying
cannabis extract (and CBD) as a "new medicine", the Government and the
MCA are treating a long-established herbal extract as if it were just another
new synthetic chemical, and are thus not making an informed scientific judgement.
26.
Campaigners against cannabis have long argued that it may have adverse effects
on human fertility. Despite 30 years of trials, however, this has never been adequately
proven. The trial to which the MCA refer in their oral evidence (Q. 2) was
based on tests in small numbers of animals, and the results were equivocal, even
though the administered doses of CBD were 100-1000 times higher than those proposed
for any human medicine. In short, we regard the raising of this unsubstantiated
issue as further evidence that the MCA have not adopted a positive approach towards
the licensing of a cannabis-based medicine. 27.
We are concerned that the MCA's approach to the licensing of cannabis-based medicines,
and their insistence on the provision of new toxicological data which could delay
the approval of such medicines, place the requirements of safety and the needs
of patients in an unacceptable balance. Patients with severe conditions such as
multiple sclerosis are being denied the right to make informed choices about their
medication. There is always some risk in taking any medication; patients and their
doctors should certainly be informed about the toxicological concerns that the
MCA have raised, but these concerns should not prevent them from having access
to what promises to be the only effective medication available to them.
28. Overall,
we consider that the MCA's attitude means that cannabis-based medicines are not
being dealt with in the same impartial manner as other medicines. 29.
We believe that a thorough and impartial reappraisal of the published scientific
literature on the safety of CBD and cannabis extracts should lead the MCA to reconsider
their present overly cautious stance. We are at least encouraged that the MCA
state that they are conducting a more detailed review of existing literature reports
on cannabis and CBD.
1 9th Report Session 1997-98, HL Paper 151. Back
2
Published as Appendix 2 of our 2nd Report Session 1998-99, HL Paper 39. Back
3
2nd Report Session 1998-99, HL Paper 39, p. 5. Back
4
For fuller details of these trials and research projects, see the memorandum by
the Medical Research Council (p. 33). Back
5
See the memorandum by G. W. Pharmaceuticals (p. 27) for an explanation of the
phases of clinical trials. Back
6
An oral preparation of synthetic delta-9-tetrahydrocannabinol in sesame oil is
already available as "Marinol". However, the absorption into the blood
stream via oral administration tends to be variable, such that patients either
underdose themselves and do not obtain benefit from the drug, or risk unwelcome
euphoria. Back
7
See Recommendation 8.6, paras 7.6-7.8, and Box 3 (p. 19) of our earlier Report,
Cannabis: the Scientific and Medical Evidence. Back
8
See paras 7.18-7.26. Back
9
See our earlier Report, Cannabis, Recommendation 8.6 and Box 8. Back
10
The most recent year for which figures are available. See Home Office Statistical
Bulletin (2000), "Drug Seizure and Offender Statistics, United Kingdom, 1998". Back
11
For reasons explained in our earlier Cannabis report, paras 4.17-4.18, 5.54-5.57,
and para. 8.4. Back
12
The primary active ingredients in "Cannador" capsules consist of 70%
THC and 30% CBD. Back
13
"Marinol", however, is an unlicensed drug and can only be prescribed
on a named-patient basis. It is not generally available and has to be imported
from the USA. Back
14
Dr Davis calls them "new products" (Q. 22); the Home Office, in their
written memorandum (p. 28), state that before any cannabis-based medicine could
be prescribed, it would have to go through the same procedures as "all prospective
new medicines". Back
15
See our earlier Report, Cannabis, Chapter 2. Back
Summary
of Conclusions
| 1. | We
are concerned at the slow progress made by the two MRC-funded trials. We consider
that the current requirement to obtain Home Office licences, and the stigma attached
to cannabis, is effectively inhibiting research in this area. |
| | |
| 2. | We
are pleased that the Home Office is showing the first signs of adopting a genuinely
pragmatic and expeditious approach to the issue of cannabis-based medicines. |
| | |
| 3. | The
Minister considered that the attitude of the police, the Crown Prosecution Service
and the courts, reflects "an understanding that where cannabis is used for
medicinal purposes, that is to be considered in a somewhat different light to
purely recreational use" (Q. 49). Noting the inconsistency with which the
law is presently applied across the United Kingdom, we endorse this view, and
further consider it undesirable to prosecute genuine therapeutic users of cannabis
who possess or grow cannabis for their own use. | | | |
| 4. | We
consider that the Medicines Control Agency are not approaching the question of
licensing cannabis-based medicines in a properly balanced way, especially given
the long-established history of cannabis use, and the needs of patients for whom
there is no medicinal alternative. To end the delay in the development of an effective
cannabis-based medicine, we recommend that the MCA should reconsider their position
on the licensing of medicines containing cannabidiol. |
Since
the MCA gave oral evidence to our inquiry, we understand that they have conducted
a review of their decisions regarding cannabis and cannabidiol, and that they
are considering modifications to their position set out in this report.
|
Appendix
1
Members
of the Select Committee
Lord Flowers (co-opted)
Lord Haskel
Lord Howie of Troon
Lord Jenkin
of Roding
Lord Lewis of Newnham
Lord McColl of Dulwich
Lord Methuen
Lord Oxburgh
Lord Patel
Lord Perry of Walton (Chairman for this Inquiry)
Baroness Platt of Writtle
Lord Quirk
Lord Rea
Lord Wade of Chorlton
Baroness Walmsley
Lord Walton of Detchant
Baroness Warwick of Undercliffe
Baroness Wilcox
Lord Winston (Chairman of the Select Committee)
The
Committee appointed as its Specialist Adviser:
Professor Leslie Iversen
FRS, Visiting Professor of Pharmacology, University of Oxford
Declarations
of interest
Lord Rea—Trustee (unpaid) of the Medicinal Cannabis Research
Foundation, set up by G. W. Pharmaceuticals
Lord Walton of
Detchant—Former President: British Medical Association, Royal Society of Medicine,
General Medical Council, Association of British Neurologists, World Federation
of Neurology. Former member: Medical Research Council
Lord Winston—Director
of NHS Research and Development, Hammersmith Hospital NHS Trust, London
|
Appendix
2
Witnesses
The
following witnesses gave evidence. Those marked * gave oral evidence.
| Alliance
for Cannabis Therapeutics | | * | Charles
Clarke MP, Minister of State, Home Office | | * | Dr
Brian Davis, Medicines Control Agency, Licensing Division |
| G.
W. Pharmaceuticals Ltd | | Medical
Research Council | | * | Medicines
Control Agency | | * | Ms
Judy Sanderson, Health Services Directorate, Department of Health |
| ORAL
EVIDENCE
Charles
Clarke MP, Minister of State, Home Office, Dr Brian Davis & Mr David Snowdon,
Medicines Control Agency and Ms Judy Sanderson, Health Services Directorate, Department
of Health
Oral Evidence, 7 February 2001 WRITTEN
EVIDENCE
Alliance
for Cannabis Therapeutics
G. W. Pharmaceuticals Ltd
Home Office
Medicines
Control Agency
Medical Research Council | 
