Lukas Radbruch, Chair of Palliative Medicine, University of Bonn, Germany
Cannabis has been recommended for symptomatic treatment of pain, nausea, vomiting, appetite loss and depression in palliative care patients, though the evidence from clinical trials was rather weak on all these indications. The analgesic efficacy seems to be equal to codeine, the antiemetic effect comparable to haloperidol, and an effect on appetite was absent in a large randomised controlled trial. Recently a cannabis extract sublingual spray (containing tetrahydrocannabinol and cannabidiol) has been released in Europe for patients with spasticity-related pain from multiple sclerosis that is not adequately treated with other drugs.
The Green Party initiated a hearing on the use of cannabis in the German Parliament on 9 May 2012, with the goal to facilitate the access to cannabis for patients with chronic pain and to ensure reimbursement from the sickness funds for medical cannabis and cannabinoid drugs.
In Germany, several options are available for patients with an indication for cannabis treatment. Delta-9-tetrahydrocannabinol (dronabinol) is scheduled in the German narcotic drug legislation, but can be prescribed up to an amount of 500 mg per month. Dronabinol is available either as an import from the UK or US (Marinol), which is rather expensive, or as a magistral preparation from ready-made sets that are available from two German pharmaceutical companies, or since May 2012 as the registered drug with cannabis extract (Sativex). Patients can also apply to the Federal Institute of Drugs and Medical Devices (BfArM) to import medicinal cannabis from the Netherlands (Bedrocan). All these options are expensive, resulting in monthly treatment costs of 1,500 Euros or more, and the sickness funds do not reimburse these costs, leaving a considerable financial burden on the patients, who are chronically ill and disabled.
Considering the high costs, repeated attempts have been made by patients and lobby groups to allow use of cannabis from the black market, imported from Dutch coffee shops or self-grown cannabis for medical purposes in selected patients. This was supported by several patient support groups in the hearing.
Representing the German Medical Board and the Drug Commission of the German Medical Association at the hearing, I was able to state that cannabis treatment should be restricted to dronabinol, as there is no evidence that other cannabinoids add to the analgesic or antiemetic effect, and that self-grown cannabis or cannabis from other sources (black market) might endanger patients, not only because the dronabinol content may vary in a wide range, but also because of impurities and bacterial or fungal contaminations, with potentially serious implications in immune deficient patients.
Dronabinol is a useful drug for a range of indications such as pain related to spasticity (not only from multiple sclerosis), nausea and appetite loss. However, its usefulness is restricted by the narrow therapeutic window: with low dosages the effect is inadequate, with higher dosages patients suffer from the side effects such as sedation. Hopefully, future research on cannabinoids will lead to derivates with a broader therapeutic window, which then may be a valuable option in the palliative care drug cabinet.