Plant-Derived and Endogenous Cannabinoids in Epilepsy.

Cannabis is one of the oldest psychotropic drugs and its anticonvulsant properties have been known since the last century. The aim of this review was to analyze the efficacy of cannabis in the treatment of epilepsy in adults and children. In addition, a description of the involvement of the endocannabinoid system in epilepsy is given in order to provide a biochemical background to the effects of endogenous cannabinoids in our body. General tolerability and adverse events associated with cannabis treatment are also investigated. Several anecdotal reports and clinical trials suggest that in the human population cannabis has anticonvulsant properties and could be effective in treating partial epilepsies and generalized tonic-clonic seizures, still known as "grand mal." They are based, among other factors, on the observation that in individuals who smoke marijuana to treat epilepsy, cessation of cannabis use precipitates the re-emergence of convulsive seizures, whereas resuming consumption of this psychotropic drug controls epilepsy in a reproducible manner. In conclusion, there is some anecdotal evidence for the potential efficacy of cannabis in treating epilepsy. Though there has been an increased effort by patients with epilepsy, their caregivers, growers, and legislators to legalize various forms of cannabis, there is still concern about its efficacy, relative potency, availability of medication-grade preparations, dosing, and potential short- and long-term side effects, including those on prenatal and childhood development.