The Dutch government will fund $1.2 million of research to study the optimal dosage of THC and CBD for the treatment of neuropathic pain.
The project is led by the Center for Human Drug Research (CHDR), a Dutch clinical drug research institute, and Leiden University Medical Center (LUMC). Bedrocan will provide the raw material for the study, and Echo Pharmaceuticals will produce the tablets containing THC and CBD.
We will isolate THC and CBD and deliver them in tablet form in different proportions. We will then examine the influence of CBD on the effects of THC and investigate which THC: CBD combination is best for the treatment of neuropathic pain,” said Geert Jan Groeneveld, Neurologist at CHDR.
We want to approach this research exactly as a drug developer would,” said Geert Jan Groeneveld. “As a clinical pharmacologist, you extract the known pharmacological components from a plant and research with it. That is also innovative in this research.
Researchers will measure the pharmacodynamics and pharmacokinetics of THC and CBD, the effects of both substances on pain and brain function, and the behavior of the substances in the human body.
What does science say about the effect of THC: CBD on neuropathic pain?
THC and CBD are the two most studied active cannabinoids of the cannabis plant. THC is known for its analgesic effect, and also causes psychoactive side effects. CBD, on the other hand, may cause analgesic effects through other mechanisms and modulates the psychotropic effects of THC.
In the first part of the study, healthy subjects will be given tablets with different ratios of THC and CBD to show whether the anxiety-inducing effects of THC can be reduced by simultaneously administering CBD, as the scientific literature has so far provided contradictory results on the subject.
To be honest, I don’t expect much from CBD alone as a treatment for neuropathic pain. From a pharmacological point of view, THC likely affects pain, but this is less the case for CBD. CBD may affect inflammation, but there is no reason to use CBD as a treatment for inflammatory pain. We already have ibuprofen for this. It will only become interesting if the side effects of THC, such as feelings of anxiety, can be alleviated by administering CBD at the same time”, Geert Jan Groeneveld explained.
Some patients already use CBD to relieve their inflammatory pain. The exact effect of CBD on pain is uncertain: is it directly a pharmacological action of CBD, or is it simply that CBD prevents the metabolism used by analgesics?
Once the results of the first study are known, a second study will examine the effects on pain and explore the best THC: CBD dosage. The second study will be conducted in a group of 200 patients with different neuropathic pain conditions.
Exploring the sources of pain
We are going to phenotype this group a long time in advance,” Groeneveld said. “This means that we want to know exactly how neuropathic pain manifests itself specifically in this group. Do patients have demonstrable nerve damage, do they have a personality disorder, are they depressed, or do they have sleep disturbances? These are all variables that we are going to map.
Upon completion of the first two studies, participants in a crossover study will receive a placebo for five weeks and, after a washout period, will receive five weeks of treatment with cannabinoids or THC. The pain will be measured at each treatment period.
“In patients with clear pain relief, we want to further investigate whether there is a correlation between their variables, such as sleep problems, anxiety or peripheral nerve damage, and response to THC treatment,” said Groeneveld.
The first part of the study will start in the spring of 2021, and Groeneveld expects the first results this summer. The second part of the study with pain patients will begin in the fall of 2021 and will last at least two years.