Marijuana 'Treatment' Needs Scientific Testing
To the Editor:
This story in the Tampa Bay Times reported that Florida legislators agreed to file a bill to legalize the medical use of marijuana that has a high content of the chemical compound cannabidiol to "treat" severe epileptic seizures in children.
The families pleaded with lawmakers to legalize strains of marijuana such as "Charlotte's Web" saying it is their last, best hope of relieving the uncontrollable seizures in their medically fragile children. The strain is high in cannabidiol or CBD, the ingredient that controls seizures, but is low in tetrahydrocannabinol, THC, the compound that creates a high. Their emotional pleas convinced the chairman of the legislative committee of the Florida House to support such a bill.
Naturally, any opponent of such a move will be considered a heartless and uncaring individual. Most probably, the medical ethics of physicians opposing such a decision will be questioned, too.
But let's consider the facts: Charlotte's Web is a strain of medical marijuana developed in Colorado by the Stanley brothers and featured in the 2013 CNN documentary "Weed," hosted by Sanjay Gupta. It is named after Charlotte Figi, who experienced an immediate and remarkable reduction of her epileptic seizures after her first dose of medical marijuana at 5 years of age.
The sudden publicity of this specific strain of medical marijuana is based on anecdotal evidence only but is now being used to justify the use of medical marijuana in general. Well meaning proponents of clinical research point out that such clinical research is blocked by strict Federal laws. Therefore, they call for reclassification of marijuana to facilitate the kind of rigorous evaluation that’s needed to determine the appropriate, physician-supervised doses and uses of medical marijuana.
But before we join the chorus singing the praise of medical marijuana we should step back and analyze the facts. I recommend reading an article published in the Epilepsy Curr. 2013 Mar-Apr; 13(2): 81–82 titled " Slim Evidence for Cannabinoids for Epilepsy" which concluded that no reliable conclusions can be drawn at present regarding the efficacy of cannabinoids as a treatment for epilepsy. The dose of 200 to 300 mg daily of cannabidiol was safely administered to small numbers of patients, for generally short periods of time, and so the safety of long term cannabidiol treatment cannot be reliably assessed. The authors base their assessment of the efficacy of marijuana, or one of marijuana's constituents in the treatment of people with epilepsy on an exhaustive search of the Cochrane Epilepsy Group Specialized Register (May 15, 2012), the Cochrane Central Register of Controlled Trials (CENTRAL issue
4 of 12, and the Cochrane Library 2012), MEDLINE (PubMed, searched on May 15, 2012), ISI Web of Knowledge.
This Cochrane review searched for direct evidence that cannabinoids can prevent human seizures in studies using the only acceptable standard, the randomized controlled trial. The researchers identified four studies, with a total of 48 patients randomized to placebo or to 200–300 mg of cannabidiol per day. This particular cannabinoid has few psychotropic effects and is not a controlled substance. Overall, these studies demonstrate the short-term tolerability of this treatment, with the only noted adverse effect being drowsiness in one study.
Except for one study that reported two of four treated patients becoming seizure free for 3 months, the studies either reported no benefit, or the effect was not clearly stated. Methods of randomization or determining outcome were inadequate or not clearly detailed.
Marijuana itself has major shortcomings as an epilepsy treatment. Its psychotropic action can only be regarded as an adverse effect. It is a biological product containing multiple compounds with unclear, possible, anti- or pro-convulsant effects, delivered in varying amounts from dose to dose. Long-term safety has not been adequately investigated.
The authors correctly stated that new treatments for epilepsy are sorely needed. Cannabidiol or other individual cannabinoids with minimal adverse effects could be extracted and given in precise doses in rigorously designed, blinded, randomized clinical trials to test efficacy and safety.
In my opinion this is the only reasonable route for development of new anti-epileptic drugs. Legislative efforts, as well intended they may be, cannot substitute for the gold standards of scientific evidence.
Unfortunately, nobody seems to have the fortitude to stand up and to defend those principles in public. I am afraid that medical science will have to succumb to populism and the efforts to create quick fixes and miracle cures. But at what price?
Family Physician of the Year Award, 2012
North Miami Beach