In this review, state-of-the-art evidence on the relationship between cannabis use, traffic crash risks, and driving safety were analyzed. Systematic reviews, meta-analyses, and other relevant papers published within the last decade were systematically searched and synthesized. Findings show that meta-analyses and culpability studies consistently indicate a slightly but significantly increased risk of crashes after acute cannabis use. These risks vary across included study type, crash severity, and method of substance application and measurement. Some studies show a significant correlation between high THC blood concentrations and car crash risk. Most studies do not support this relationship at lower THC concentrations. However, no scientifically supported clear cut-off concentration can be derived from these results. Further research is needed to determine dose-response effects on driving skills combined with measures of neuropsychological functioning related to driving skills and crash risk.
ABSTRACT: Cannabis is the third most used psychoactive substance worldwide. The legal status of cannabis is changing in many Western countries, while we have very limited knowledge of the public health impact of cannabis-related harms. There is a need for a summary of the evidence of harms and risks attributed to cannabis use, in order to inform the definition of cannabis risky use. We have conducted a systematic review of systematic reviews, aiming to define cannabis-related harms. We included systematic reviews published until July 2018 from six different databases and following the PRISMA guidelines. To assess study quality we applied the AMSTAR 2 tool. A total of 44 systematic reviews, including 1,053 different studies, were eligible for inclusion. Harm was categorized in three dimensions: mental health, somatic harm and physical injury (including mortality). Evidence shows a clear association between cannabis use and psychosis, affective disorders, anxiety, sleep disorders, cognitive failures, respiratory adverse events, cancer, cardiovascular outcomes, and gastrointestinal disorders. Moreover, cannabis use is a risk factor for motor vehicle collision, suicidal behavior and partner and child violence. Cannabis use is a risk factor for several medical conditions and negative social consequences. There is still little data on the dose-dependency of these effects; evidence that is essential in order to define, from a public health perspective, what can be considered risky use of cannabis. This definition should be based on quantitative and qualitative criteria that informs and permits the evaluation of current approaches to a regulated cannabis market. (PsycINFO Database Record (c) 2020 APA, all rights reserved)
OBJETIVO: Brindar orientación preliminar sobre la prescripción de cannabis fumado para el dolor crónico antes de la publicación de directrices formales.
CALIDAD DE LA EVIDENCIA: Revisión de la literatura sobre la eficacia analgésica del cannabis fumado y los daños del consumo de cannabis medicinal y recreativo. Hemos desarrollado recomendaciones sobre las indicaciones, contraindicaciones, precauciones y dosificación de cannabis fumado, y categorizaron las recomendaciones basadas en los niveles de evidencia. La evidencia es en su mayoría de nivel II (estudios observacionales bien realizados) y III (opinión de expertos).
MENSAJE PRINCIPAL: cannabis fumado podría estar indicada para pacientes con dolor neuropático graves que no han respondido a los ensayos adecuados de los cannabinoides farmacéuticas y analgésicos habituales (nivel II). Cannabis fumado está contraindicado en pacientes que son 25 años de edad o menos (nivel II); que tienen una corriente, pasado, o fuertes antecedentes familiares de psicosis (nivel II); que tienen un trastorno por consumo de cannabis actual o pasada (nivel III); que tienen un trastorno de drogodependencia (nivel III); que tienen enfermedad cardiovascular o respiratoria (nivel III); o que están embarazadas o que planean quedar embarazadas (evidencia de nivel II). Debe utilizarse con precaución en pacientes que fuman tabaco (evidencia de nivel II), que están en mayor riesgo de enfermedad cardiovascular (nivel III), que tienen la ansiedad o los trastornos del humor (nivel II), o que están tomando dosis más altas de opiáceos o benzodiacepinas (evidencia de nivel III). Los consumidores de cannabis deben ser advertidos de no conducir durante al menos 3 a 4 horas después de fumar, por lo menos 6 horas después de la ingestión oral, y durante al menos 8 horas si experimentan una subjetiva "alto" (nivel II). La dosis máxima recomendada es de 1 inhalación 4 veces al día (400 mg aproximadamente por día) de hojas secas de cannabis que contiene 9% de delta-9-tetrahidrocannabinol (nivel III). Los médicos deben evitar la derivación de pacientes a las clínicas "cannabinoides" (evidencia de nivel III).
CONCLUSIÓN: Las futuras directrices deberían basarse en la revisión sistemática de la literatura sobre la seguridad y eficacia del cannabis fumado. Se necesita más investigación sobre la eficacia y seguridad a largo plazo del cannabis fumado en comparación con cannabinoides farmacéuticas, opioides y otros analgésicos habituales.
In this review, state-of-the-art evidence on the relationship between cannabis use, traffic crash risks, and driving safety were analyzed. Systematic reviews, meta-analyses, and other relevant papers published within the last decade were systematically searched and synthesized. Findings show that meta-analyses and culpability studies consistently indicate a slightly but significantly increased risk of crashes after acute cannabis use. These risks vary across included study type, crash severity, and method of substance application and measurement. Some studies show a significant correlation between high THC blood concentrations and car crash risk. Most studies do not support this relationship at lower THC concentrations. However, no scientifically supported clear cut-off concentration can be derived from these results. Further research is needed to determine dose-response effects on driving skills combined with measures of neuropsychological functioning related to driving skills and crash risk.
