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American Herbal Pharmacopoeia Releases Scientific Review of Cannabis for Seizures and Epilepsy

The nonprofit American Herbal Pharmacopoeia (AHP) recently issued a draft of its comprehensive review of medicinal cannabis for difficult-to-treat seizure conditions, including epilepsy. AHP’s announcement in mid-March came roughly six months after Illinois became the 20th state to legalize medical marijuana (Cannabis spp., Cannabaceae) and as proposed medicinal cannabis legislation was being debated in 15 other states.1

The document — titled “Cannabis in the Management and Treatment of Seizures and Epilepsy”2 — is an excerpt from AHP’s forthcoming Cannabis Therapeutic Compendium, which will be published later this year. The compendium contains “numerous scientific reviews [encompassing] the broad range of science regarding the therapeutic effects and safety of cannabis”3 and is the companion document to AHP’s historic cannabis quality standards monograph released in December 2013, the first document of its kind to be published in the United States for more than 70 years.4

Despite AHP’s two recent publications on cannabis, the organization is chiefly an herbal medicine education nonprofit without vested interests in any particular herb. AHP is known for producing meticulously researched herb monographs and literature reviews. Its 34th monograph — on aloe vera (Aloe vera, Xanthorrhoeaceae) leaf, leaf juice, and inner leaf juice — was released in December 2012.5

“AHP is not a cannabis advocacy organization,” explained AHP Executive Director Roy Upton (email, March 25, 2014). “Our job is simply to provide a scientific and critical review of the literature. How it is interpreted or used is up to the readers.”

AHP released its review of cannabis for seizures and epilepsy amid increased news coverage of the use of medical marijuana, particularly by children with these neurological disorders. CNN’s Chief Medical Correspondent Sanjay Gupta, MD, brought national attention to the issue in his August 2013 documentary Weed, which focused on the story of a six-year-old girl in Colorado whose intractable seizures were controlled by a cannabis extract when conventional pharmaceutical medications failed to work.6 Dr. Gupta’s follow-up documentary (see page 30 for a review by HerbalGram Managing Editor Ash Lindstrom) aired on March 11, 2014, the day before AHP released its review document, and reiterated that select cannabis extracts are effective for the management of seizures.7

“In recent months there has been considerable attention given to the potential benefit of cannabis for treating intractable seizure disorders including rare forms of epilepsy,” AHP noted in its press release.3 “For this reason, the lead author of the section, Ben Whalley, PhD, and AHP felt it important to release this section, in its near-finalized form, into the public domain for free dissemination.”

Dr. Whalley, director of research at the University of Reading’s School of Pharmacy in the United Kingdom, has published multiple papers on cannabis for the treatment of seizure disorders with a focus on the underlying brain mechanisms of these conditions.3

“Releasing this section of the monograph,” Dr. Whalley stated in AHP’s press release, “provides clinicians, patients, and their caregivers with a single document that comprehensively summarizes the scientific knowledge to date regarding cannabis and epilepsy and so fully support informed, evidence-based decision making.”3

According to the Maryland-based Epilepsy Foundation, approximately 2.3 million Americans currently live with this often-debilitating neurological condition. “There is an enormous unmet need for better treatments for children and adults with epilepsy,” wrote Orrin Devinsky, MD, a member of the Epilepsy Foundation’s National Board of Directors and director of New York University’s Comprehensive Epilepsy Center, in a commentary article accompanying a recent press release from the Epilepsy Foundation.8

“Approximately one-third of people with epilepsy continue to suffer from seizures despite the best medical, dietary, and surgical therapies,” Dr. Devinsky continued. These effects, he said, are often “compounded by the disabling physical, cognitive and behavioral side effects from high doses of multiple antiepileptic drugs.”8

The Epilepsy Foundation has publicly called on the US Drug Enforcement Agency to reclassify cannabis,8 which is currently a Schedule I controlled substance — a category for substances deemed to have a high potential for abuse and no accepted medical use in the United States. This restrictive classification, the Foundation says, significantly hampers research efforts and limits patient access to potentially beneficial medicine.

“[A]n end to seizures should not be determined by one’s zip code,” the Epilepsy Foundation stated in a press release from March 20.8 “If a patient and their healthcare professionals feel that the potential benefits of medical marijuana for uncontrolled epilepsy outweigh the risks, then families need to have that legal option now — not in five years or ten years.”7

Although the field of medical marijuana research in the United States is still in its infancy, current evidence suggests cannabis may have positive effects in seizure treatment.2 Due to the limited amount of human research, conflicting findings, and varying study quality, however, firm conclusions about the efficacy of cannabis for seizures and epilepsy should not be made at this time.

“The available literature (case studies, surveys, and pre-clinical data) on the use of cannabis and its constituents for the treatment of epilepsy and seizures in humans suggests there is a general consensus that cannabis exerts an anticonvulsant effect,” Dr. Whalley stated.2 “[W]hilst high CBD and low THC strains … appear to be effective, their long-term efficacy and safety have not yet been properly demonstrated in well-controlled clinical trials.”

Dr. Devinsky noted that highly publicized anecdotal reports of cannabis as a “miracle cure” for treatment-resistant seizures, coupled with the current lack of a scientific consensus regarding its efficacy, can put physicians in a difficult situation.

“We stand at an unusual inflection point where families are demanding access to a medication that may or may not be beneficial, and for which the side effects may be less than many medications prescribed by doctors; the medical community lacks convincing efficacy or safety data for children with epilepsy; and the Drug Enforcement Agency’s overly conservative scheduling of marijuana hamstrings research and access,” he wrote.8 “We urgently need data from randomized controlled trials where the biases of companies, doctors, patients, and parents are meticulously removed.”

AHP’s document, “Cannabis in the Management and Treatment of Seizures and Epilepsy,” can be downloaded free of charge at A printed copy of AHP’s Standards of Identity, Analysis, and Quality Control Cannabis monograph can be purchased for $44.95 on AHP’s website.

—Tyler Smith


  1. 15 states with pending legislation to legalize medical marijuana (as of Mar. 24, 2014). website. Available at: Accessed March 21, 2014.
  2. Whalley B. Cannabis in the Management and Treatment of Seizures and Epilepsy. Scotts Valley, CA: American Herbal Pharmacopoeia; March 12, 2014. Available at: Accessed March 18, 2014.
  3. AHP Releases Cannabis in the Management and Treatment of Seizures and Epilepsy: A Scientific Review [press release]. Scotts Valley, CA: American Herbal Pharmacopoeia; March 12, 2014. Available at: Accessed March 18, 2014.
  4. Smith T. American Herbal Pharmacopoeia publishes historic monograph on cannabis. HerbalGram. 2013;101:24-25. Available at: Accessed March 21, 2014.
  5. Smith T. AHP releases quality control standards monograph for aloe vera. HerbalEGram. 2013;10(1). Available at: Accessed March 26, 2014.
  6. Gupta S. Why I changed my mind on weed. CNN Website. Available at: Accessed March 21, 2014.
  7. Gupta S. Gupta: ‘I am doubling down’ on medical marijuana. CNN website. Available at: Accessed March 21, 2014.
  8. Epilepsy Foundation calls for increased medical marijuana access and research [press release]. Landover, MD: Epilepsy Foundation; March 20, 2014. Available at: Accessed March 21, 2014.