Doctors who prescribe medical cannabis in Germany are obliged to take part in a non-interventional accompanying survey on the use of cannabis-based medicines. This survey spans six years and will be running until 31 March 2022. The interim evaluation of the survey took place on 11 May 2020 with 10,010 data records completed.
Since 2017, German law has allowed all doctors to prescribe medical cannabis products, including cannabis flower and extracts, as well as pharmaceutically developed cannabis and cannabinoid-based medicines. Medical cannabis prescriptions are largely covered by statutory health insurance with insurance companies only allowed to refuse a request for reimbursement in limited cases.
When prescribing medical cannabis in Germany, doctors are obliged to also complete an accompanying survey to monitor the use of these medicines. The results from this survey will, among other things, be used to help form the basis of the Federal Joint Committee (G-BA) “to regulate the future assumption of treatment costs as part of therapy with cannabis medicinal products according to the Social Code (SGB) V.”
The aim of the survey is to monitor the side effects and tolerability of cannabis-based medicines, estimate the frequency distribution of indications that justify treatment with medical cannabis, and to provide an orientation assessment of the efficiency as a basis for planning clinical studies.
Findings of the Interim Evaluation
At the time of the interim evaluation, a total of 10,010 data sets had been submitted to the survey. Cannabis prescriptions were mainly carried out in the fields of anaesthesiology (49%) and general medicine (17%). The data shows that anaesthesiologists tended to favour the prescription of dronabinol and Sativex, while cannabis flower was more commonly prescribed through general practitioners.
The interim evaluation points out that 56% of prescribing doctors carried the additional designation special pain therapy while 39% had further training in palliative medicine.
Reasons for Medical Cannabis Use
This data showed that the majority of medical cannabis was prescribed for pain (73%), followed by spasticity (10.3%), and anorexia/wasting (6.4%) – all of which may be symptoms of other conditions.
Symptoms associated with cancer
Pain, anorexia/wasting, spasticity, and nausea/vomiting are all symptoms of cancer for which medical cannabis may be prescribed under German law. The interim evaluation shows that a total of 1831 patients (18% of the total) had a malignant neoplasm. In 49% of those patients treated with medical cannabis, pain was the primary reason for prescription (49%), followed by anorexia/wasting (27%), nausea and vomiting (12%), and spasticity (2%).
The therapeutic success of medical cannabis in all four symptom categories was most often reported as moderately improved. Furthermore, in the 227 cases with nausea and vomiting reported as the primary symptom, a clear improvement was reported in 34% of cases.
Reported Side Effects
Common side effects of medical cannabis medicines such as tiredness, dizziness, mouth, and nausea were reported with all cannabis medicines covered in the survey. More serious adverse effects including depression, suicidal ideation, delusions, hallucinations, dissociation, and misconceptions were each reported with a frequency of higher than 0.1%.
A total of 3,499 patients stopped treatment before 12 months. The most common side effects experienced by dropout patients were fatigue (20%), dizziness (18%), and sleepiness (10%). Furthermore, the misuse of medical cannabis products and/or the co-use of illicit cannabis were reported in 27 cases – also as a reason for discontinuing therapy.
Patients treated with Sativex were more likely to experience side effects than those treated with dronabinol or cannabis flower (16% in comparison to 7% in each dronabinol and cannabis flower cases). This finding may counter previous assumptions that levels of CBD may make THC therapy more tolerable.
Application of Medical Cannabis Products
The most commonly prescribed medical cannabis product was Dronabinol (65%), followed by cannabis flower (18%), Sativex (13%), cannabis extract (4% with increasing frequency), and nabilone (0.3%).
The prescription of cannabis flower represented 1343 cases with the most common type of application being vaporisation. Cannabis flower varieties with a THC content of >20% were more common (1027 [77%] of 1343). In 207 cases, up to four types of flower were prescribed for the patient’s first prescription and in 782 cases, the type, method of application, and dosage remained unchanged throughout the course of therapy.
The prescription of cannabis flower was more common in male patients, with this group representing 68% of cannabis flower prescriptions. This group of patients were also, on average, significantly younger, were more likely to have had previous experience with cannabis therapy, and were less likely to report side effects than patients prescribed other cannabis-based medicines.
It is noted that this accompanying survey does not cover all medical cannabis patients in Germany over the study period. Data from self-payers, privately insured patients, inpatients, and people treated in clinical studies are not included. However, the data collected so far may provide an insight into the potential applications of medical cannabis in the future.
The data that has so far been collected for the survey shows that a significant proportion of patients have experienced some level of improvement to symptoms. For example, in those prescribed medical cannabis for pain (7312 cases), 34% were reported to be ‘significantly improved’, 36% were ‘moderately improved’, and 28% were ‘unchanged’.
Furthermore, the prescription of dronabinol for appetite stimulation (125) was associated with therapeutic success reported as ‘significantly improved’ in 22% of cases, ‘moderately improved’ in 42% of cases, and ‘unchanged’ in 36% of cases. In spasticity associated with multiple sclerosis, symptoms were also ‘significantly improved’ in 41% of cases, ‘moderately improved’ in 43% of cases, and ‘unchanged’ in 15%.
While these figures may, in some areas, be considered promising, the authors of this interim evaluation acknowledge that the anonymous results submitted in this survey cannot replace more detailed clinical trials and studies, which are still needed to support existing evidence.