Cardiovascular Effects of Marijuana.

Plants of the Cannabis species, commonly known as marijuana, contain numerous psychoactive components, including the primary psychoactive compound D-9-tetrahyrdocannabinol (THC). The World Health Organization (WHO) describes cannabis as the most widely used, cultivated, and trafficked illicit drug in the world, with an estimated 147 million people using the drug annually. Consistent with worldwide reports, the Substance Abuse and Mental Health Services Administration estimated nearly 20 million active marijuana users in the United States in 2013, making it the most widely used illicit drug in the nation. Evidence of therapeutic potential for marijuana and its components has been suggested for a number of medical conditions, including cachexia, cancer, glaucoma, HIV/AIDS, muscle spasm, seizures, severe nausea, severe or chronic pain, and sleep disorders, though lack of scientific evidence regarding safety and efficacy has prohibited endorsement by the US Food and Drug Administration for any therapeutic use. In a 1999 Institute of Medicine (IOM) publication, the IOM made a clear call to action regarding the need for trials examining safety and efficacy. Despite the IOM’s recommendation, few trials have been published. Nevertheless, the idea that marijuana use is safe is deep seated in the public and even among some health-care professionals. As such, use of marijuana for medical purposes has been approved in several states in the United States, and some physicians routinely prescribe cannabis to patients, particularly in instances of chronic pain or muscle spasms. In a recent publication related to the use of cannabinoids for the treatment of epilepsy in the New England Journal of Medicine, Friedman and Devinsky did an outstanding job of highlighting some of the major barriers to scientific investigation surrounding the therapeutic use of cannabis-related compounds. Despite these challenges, it is important that cannabis be evaluated like any other drug, weighing both the benefits and the side effects before universal acceptance the scientific community. Furthermore, recent legalization of recreational use in a number of states presents substantial concerns about the potential for risk in the absence of any therapeutic benefit. The potential for harmful cardiovascular effects of marijuana was first reported several decades ago, which, combined with known effects on behavior and cognitive function, prompted a surgeon general warning against marijuana use in August 1982. A recent review of reports over the past 2 decades describes ongoing evidence of adverse effects of marijuana use on rates of accidents and injuries, cognitive function, psychosocial consequences, and mental and physical health outcomes. In an era of ongoing illicit use of cannabis and increasing momentum toward legalization for recreational purposes, it is important that the medical community consider the physical health risks associated with recreational cannabis consumption, as such concerns are likely to present in the clinical setting. In this article, we discuss the potential cardiovascular effects of marijuana, with particular focus on its effects on the coronary, cerebral, and peripheral vasculature.