Sergio Islas-Andrade, Luisa L. Rocha-Arrieta, Oscar Arrieta, Miguel A. Celis, Judith Domínguez-Cherit, Alberto Lifshitz*, Armando Mansilla-Olivares, Iris Martínez, Alberto José Mimenza, Mucio Moreno, Alejandro A. Reyes-Sánchez, Guillermo J. Ruiz-Argüelles, Antonio Soda-Merhy, Julio Sotelo, Sonia Toussaint, Diana Vilar-Compte, Emma Verástegui
Comité de Ética y Transparencia en la Relación Médico-Industria (CETREMI), Academia Nacional de Medicina de México, Mexico City, Mexico
Cannabis has been used for medicinal purposes for many years; its prohibition in the mid-twentieth century has halted research into its therapeutic utility. In recent years, the debate on the use of cannabis for medical purposes has escalated. The expression “medicinal cannabis” refers to the use, recommended by a doctor, of the plant and its components, called cannabinoids, to treat diseases or for reducing symptoms. Chronic pain is the most commonly cited reason for using “medicinal cannabis”.
Cannabis, specifically the sativa species, is a herbaceous plant that grows spontaneously in tropical and subtropical regions; between 400 and 537 chemical components and close to 100 cannabinoids have been identified in this plant. Research on cannabis derivatives has established that this plant has psychotropic and therapeutic effects mediated by cannabinoids, among which phytocannabinoids (directly extracted from Cannabis sativa and Cannabis indica, such as delta-9-tetrahydrocannabinol, and that possess psychotropic effects) and other cannabinoids with some potential therapeutic effect stand out.
Unlike endocannabinoids, which are synthesized in the brain and act as CB1 and CB2 receptor agonists, phytocannabinoids and laboratory-manufactured cannabinoids act on different therapeutic targets such as 5-HT1A serotonin receptor, opioid and dopamine receptors and GABA A receptor, among others. In fact, phytocannabinoids are CB1 and CB2 receptor antagonists.
Currently, several countries use cannabis for medicinal purposes. In Latin America, Uruguay was the first nation to carry out this action in 2013. In Mexico, on June 19, 2017, the Official Journal of the Federation published reforms and additions related to the use of tetrahydrocannabinol, isomers and stereochemical variants derived from marijuana; these reforms legalized the use of cannabinoids for medical purposes. The Ministry of Health was entrusted with the formulation and application of public policies that regulate cannabis use for medical purposes, research, and national production. In December 2017, the Ministry of Health of Mexico published guidelines on the use of cannabis for medical purposes. In October 2018, the Supreme Court of Justice of the Nation ruled that the prohibition of consumption for non-medical purposes was unconstitutional.
Preliminary studies have shown the efficacy of cannabis for various physical and mental health problems. Before 2012, only nine studies on the use of cannabinoids for the management of pain had been published. After that date, 30 articles have been published on this subject, according to a 2017 PubMed review. One of the most important was carried out in the University of California, at San Diego Cannabis Research Center, in which the cannabis cigarette was shown to reduce pain by 34 to 40% more than placebo.
In preliminary studies at Dent Neurological Institute, in Buffalo, New York, it was concluded that the use of the phytocannabinoid known as cannabidiol or CBD could be indicated in geriatric patients with chronic pain associated with diseases such as sleep disorders, anxiety, neuropathy, amyotrophic lateral sclerosis, Parkinson’s disease, vertebral injuries, and multiple sclerosis.
CBD showed benefits in different neurological disorders, including epileptic seizures. A recent controlled study of children with epilepsy showed a reduction of more than 50% in the frequency of seizures. The release of endorphins experienced by runners after exercising is partly induced by anadamide, which acts on CB1 receptors, which have an anxiolytic effect.
Preclinical studies carried out in Mexico have shown that CBD reduces the severity of generalized seizures and the probability of drug-resistant epilepsy. CBD’s activity on 5-HT1A receptors has beneficial neuroprotective, antidepressant, and anxiolytic effects. Investigations in our country indicate that CBD is an allosteric agonist of the 5-HT1A receptor, which constitutes a mechanism whereby it can modulate the action of serotonin on said receptor and increase anxiolytic effects.
During 2013, the National Academy of Medicine and the Faculty of Medicine of the National Autonomous University of Mexico, through the Seminar of Studies on the Globalization Phenomenon, decided to carry out a systematic review about a topic that is as complex as controversial: the relationship between marijuana and health.
The pharmaceutical industry and research centers are advised to promote research on the safety and efficacy of the different types of cannabinoids in patients.
The medical community is invited to seek information based on scientific evidence and issue supported clinical recommendations.
Medical groups are encouraged to disseminate more information based on scientific knowledge on the subject.
In addition, it is important to facilitate phytocannabinoids production and import processes in order to promote their clinical and preclinical investigation in different brain disorders.
The authors declare that they have not received any funding for this study.
Conflicts of interest
The authors declare that they have no conflicts of interest.
Protection of human and animal subjects. The authors declare that no experiments were performed on humans or animals for this research.
Confidentiality of data. The authors declare that no patient data appear in this article.
Right to privacy and informed consent. The authors declare that no patient data appear in this article.