The illicit and licit cannabis industry has generated many thousands of strains of herbal cannabis but the scientific literature and regulation has not caught up to the dizzying variety of cannabis available to medical cannabis patients.
This study collates evidence from different studies that record and evaluate the efficacy of different forms of cannabis and finds some that different types of cannabis can be generally effective in the treatment of epilepsy but adverse effects were essentially impossible to predict with different strains of THC,THCA or CBD rich cannabis.
Here is the full scientific article if you wish to download it.
Concern over the translation of small-scale studies on the effects of carefully measured and purified cannabis extracts into real world situations where patients are choosing their own cannabis strains is very real. The effect of combining cannabis with other drugs has not been properly evaluated, though other data suggest that combining drugs reduces their efficacy.
The efficacy of artisanal cannabis for the treatment of epilepsy is roughly the same as for the specially prepared and dosed cannabinoids used in clinical trials. However, because of the huge variation in the concentrations of cannabinoids like THC, THCA, and CBD in cannabis on the market, there is significant risk of a patient obtaining and using a strain of cannabis that would actually promote their seizures.
This happens in about 5% of cases with artisanal cannabis. However, the overall profile of artisanal cannabis is not unfavorable, with 86% of patients reporting some benefit, and 10% experiencing total cessation of seizures.
In the absence of regular testing for cannabinoid concentrations, it is basically impossible in some cases for a patient to know whether the strain of cannabis that they have just bought will be as effective as the last. While the medical cannabis industry is improving, concentrations do vary and strength tapers off with time.
For people who need precisely controlled quantities of medicine for their epilepsy, this situation is unacceptable. Testing of every batch is needed if the patient is to properly evaluate the efficacy and risk of their medicine.
Although the risks are low, there do exist significant risks with taking cannabis for epilepsy. The interactions of cannabis with other drugs is not well known. It needs more study. More concerning, however, is the possibility of a patient receiving a strain of cannabis that has a different concentration of cannabinoids than the previously successful strain had. This could exacerbate their condition and put them at significant risk of harm.
About 5% of patients report that cannabis makes their seizures more frequent. The authors believe that this could be partially due to the wrong concentrations of cannabis in the strain that the patient took. Independent testing, established standards, and enforced consistency, as well as individualized treatments, is thought to be the way to reduce this risk.
Cannabis is generally tolerable, safe, and effective for some forms of intractable epilepsy. However, the variation in artisanal cannabis that is available through shops and on the street is a cause for concern because it is often impossible to get consistent cannabis that is suited to the individual’s condition. A system of regulation is advised.