Voici la retranscription de notre entretien avec le docteur Franjo Grotenhermen, réalisé le 22 février 2011, par mail :


1. Quelles sont d'après vous les vertus et bénéfices de l'utilisation médicale du cannabis?

The main uses for cannabis are three complexes: (1) chronic pain, (2) neurological disorders (including spasticity in multiple sclerosis, Tourette syndrome, etc.), (3) appetite loss/nausea and vomiting in cancer, HIV/Aids, etc.


2. Le cannabis médical présente-t-il également, selon vous, des risques?

As other medications cannabis may cause unwanted side effects, which in several cases may be so strong that patients cannot use cannabis. The main side effects concern circulation (increased heart rate, hypotension) and psychological effects ("high", distortion of time perception, anxiety, paranoia, etc.).


3. Comment qualifieriez-vous le rapport bénéfices/risques du cannabis en tant que médicament?

This varies from patient to patient. One has to keep in mind that cannabis is used for serious diseases and that the side effects are usually relatively low compared to the possible benefits. However, as stated in question two the risk/benefit ratio may be unfavourable in several patients. If patients tolerate cannabis well they have found a good medication because long-term side effects are low. This is mainly due to the fact that cannabis has no or only little negative effects on stomach, liver, heart and kidneys, which is not the case for many other medications.

4. Quel rôle jouent les modes d'administration du produit en tant que médicament dans ce rapport bénéfices/risques? 

The best ways to use cannabis is by oral route or by inhalation with a vaporizer to avoid the inhalation of combustion products associated with smoking. However, one should have in mind that the combustion products are similar to those produced by smoking tabacco, which is legal even for non-medical use in most countries.


5. Quel mode d'administration (boire/inhaler/manger/absorber par la peau) serait-il le plus adapté pour l'usage du cannabis comme médicament?

See question 4.


6. Que pouvez-vous nous dire sur la notion d'automédication de la part des patients? Et spécialement en ce qui concerne le cannabis médical.

It is a pity that many patients have no other alternative than to treat themselves with cannabis without guidance by a doctor since the medical use is not accepted/legal in most countries. I support the right for self treatment of patients with cannabis if they have no alternative. However, this is not the best solution and patients should be able to talk with their doctors and be treated by them.


7. Comment jugez vous les méthodes de classification des substances? (Méthode basée sur le critère du potentiel d'abus d'une part et de la valeur thérapeutique d'autre part)

The most scientific classifications on the dangers of cannabis rate cannabis as less dangerous than tabacco, alcohol and most other illegal drugs, see for example the last classification made by British scientists in the important scientific journal Lancet (Nutt DJ, King LA, Phillips LD; on behalf of the Independent Scientific Committee on Drugs. Drug harms in the UK: a multicriteria decision analysis. Lancet. 2010 Oct 29. [in press]). Unfortunately, these classifications are different to classifications in most legislations.


8. Que pourriez-vous nous dire sur les médicaments de la famille des cannabinoïdes actuellement disponibles? (Sativex, césamet, marinol, acomplia).

Sativex is available in Canada and the UK and it is expected that it will be available soon in other European countries, including France. Cesamet is available in Canada, the UK, Spain and some other countries, Marinol/dronabinol is available in the USA, Germany, Austria and several other countries. Acomplia is currently not available in any country, to my knowledge.


9. Quelles différences principales existent entre ces médicaments à base de cannabinoïdes et du cannabis prescrit en tant que médicament comme cela se fait en Californie?

Marinol/dronabinol contains only one compound of cannabis. Nabilone is a synthetic derivative of dronabinol and Sativex is an extract of cannabis. There is currently not much information available on differences between the different products. Cannabis preparations with high CBD concentrations such as Sativex and the cannabis variety Bediol (available in Dutch pharmacies) may have some different pharmacological effects than dronabinol alone or cannabis high in dronabinol/THC.


10. Prescrire du cannabis en tant que médicament pourrait-il, selon vous, opérer une confusion sociale et juridique dans une coexistence d'un cannabis médical et d'un cannabis considéré comme drogue?

There is no confusion concerning other medications that can be abused (mainly opiates and benzodiazepines). Surveys conducted in different countries, including the USA, Canada and Germany show very clearly that people can differentiate between the medical use of a substance (in this case cannabis) and other non-medical/recreational. In all these countries the possibilty of medical use of cannabis is supported by more than two third of the population while recreational use is usually supported only by a minority (at least in Germany).


12. La comparaison avec la morphine, aujourd'hui consacrée comme médicament est-elle, selon vous, pertinente?

There are some parallels between opiates and cannabinoids concerning medical and recreational use. However, the risk of dependency and the abuse potential is much lower for cannabinoids in a medical context.


13. Comment la recherche sur le cannabis médical s'effectue concrètement? (Observation de patients, tests sur des malades, tests sur des souris?)

Please see our overview on clinical studies on our website




14. De quelle façon les chercheurs rendent compte du lien de cause à effet en ce qui concerne le cannabis thérapeutique? Comment ces vertus médicales sont elles quantifiées?

The standard for clinical studies are controlled, randomized, double blind studies, which is also the case for cannabis and cannabinoids.


15. Plus généralement, que pouvez-vous nous dire sur les méthodes de classification des différentes substances? Que pensez-vous de la convention sur les substances psychotropes de 1971 qui définit une classification en 4 tableaux?

See question 7.


16. Quel rapport y a-t-il entre la recherche scientifique et les pouvoirs publics sur la question du cannabis médical?

Politicians in general do not follow the scientific knowledge on this issue (and also not on other issues related to drug laws). I have the impression that they like to give the impression that they are "tough on drugs", which usually results in not very rational decisions. But we also realize a change when it comes to the medical use of cannabis, which has to do with the change of opinions in the public.


17. Sur la question du cannabis médical, l'opinion publique sera, selon vous, plus sensible au discours scientifique ou à celui des pouvoirs publics? 

Please see 16.


18. Croyez vous que l'opinion publique est aujourd'hui bien informée sur le sujet?

People are better informed than ten years ago. There is a large difference between different countries.


19. Globalement, pourriez vous vous positionner comme étant pour ou contre l'utilisation médicale du cannabis? Si oui, êtes-vous pour ou contre et pourquoi?

We are supporting every step that increases the possibility of patients in need to get access to a treatment with cannabinoids and/or cannabis. The need of the patients is the centre of our work. Patients should not be denied a treatment, which can ameliorate their suffering in serious diseases. This is a human right issue.