BACKGROUND: Cannabis is increasingly available for the treatment of chronic pain, yet its efficacy remains uncertain.
PURPOSE: To review the benefits of plant-based cannabis preparations for treating chronic pain in adults and the harms of cannabis use in chronic pain and general adult populations.
DATA SOURCES: MEDLINE, Cochrane Database of Systematic Reviews, and several other sources from database inception to March 2017.
STUDY SELECTION: Intervention trials and observational studies, published in English, involving adults using plant-based cannabis preparations that reported pain, quality of life, or adverse effect outcomes.
DATA EXTRACTION: Two investigators independently abstracted study characteristics and assessed study quality, and the investigator group graded the overall strength of evidence using standard criteria.
DATA SYNTHESIS: From 27 chronic pain trials, there is low-strength evidence that cannabis alleviates neuropathic pain but insufficient evidence in other pain populations. According to 11 systematic reviews and 32 primary studies, harms in general population studies include increased risk for motor vehicle accidents, psychotic symptoms, and short-term cognitive impairment. Although adverse pulmonary effects were not seen in younger populations, evidence on most other long-term physical harms, in heavy or long-term cannabis users, or in older populations is insufficient.
LIMITATION: Few methodologically rigorous trials; the cannabis formulations studied may not reflect commercially available products; and limited applicability to older, chronically ill populations and patients who use cannabis heavily.
CONCLUSION: Limited evidence suggests that cannabis may alleviate neuropathic pain in some patients, but insufficient evidence exists for other types of chronic pain. Among general populations, limited evidence suggests that cannabis is associated with an increased risk for adverse mental health effects.
PRIMARY FUNDING SOURCE: U.S. Department of Veterans Affairs. (PROSPERO: CRD42016033623).
IMPORTANCIA: El cannabis y las drogas cannabinoides son ampliamente utilizadas para tratar enfermedades o aliviar síntomas, pero su eficacia para indicaciones específicas no está clara.
OBJETIVO: Realizar una revisión sistemática sobre los beneficios y eventos adversos (EAs) de los cannabinoides.
FUENTES DE INFORMACIÓN: Veintiocho bases de datos desde su inicio hasta abril del 2015.
SELECCIÓN DE ESTUDIOS: Ensayos clínicos aleatorizados sobre cannabinoides para las siguientes indicaciones: náuseas y vómitos debido a quimioterapia, estimulación del apetito en el VIH/SIDA, dolor crónico, espasticidad debido a esclerosis múltiple o paraplejia, depresión, trastorno de ansiedad, trastorno del sueño, psicosis, glaucoma, o síndrome de Tourette.
EXTRACCIÓN DE DATOS Y SÍNTESIS: La calidad del estudio se evaluó utilizando la herramienta de riesgo de sesgo Cochrane. Todas las etapas de revisión se llevaron a cabo de forma independiente por 2 revisores. Cuando fue posible, los datos se agruparon utilizando metanálisis de efectos aleatorios.
PRINCIPALES EVENTOS Y MEDIDAS: Eventos relevantes para el paciente/específicos de la enfermedad, actividades de la vida diaria, calidad de vida, impresión global de cambio, y EAs.
RESULTADOS: Se incluyeron un total de 79 ensayos (6462 participantes); 4 fueron evaluados como con bajo riesgo de sesgo. La mayoría de los ensayos mostraron una mejoría en los síntomas asociada a los cannabinoides pero estas asociaciones no alcanzaron significación estadística en todos los ensayos. En comparación con el placebo, los cannabinoides se asociaron con un mayor número promedio de pacientes que mostraron una respuesta completa para náuseas y vómitos (47% vs 20%; odds ratio [OR], 3,82 [IC 95%, 1,55-9,42]; 3 ensayos), reducción del dolor (37% vs 31%; OR [IC 95%, 0,99-2,00] 1,41; 8 ensayos), una mayor reducción promedio en la evaluación del dolor en la escala de calificación numérica (en una escala de 0-10 puntos; diferencia de media ponderada [DMP], -0,46 [IC del 95%, -0,80 a -0,11]; 6 ensayos), y reducción de la media en la escala de espasticidad de Ashworth (DMP, -0,36 [IC del 95%, -0,69 a -0,05]; 7 ensayos). Hubo un aumento del riesgo de eventos adversos a corto plazo con los cannabinoides, incluyendo EAs graves. Los EAs comunes incluyeron mareos, boca seca, náuseas, fatiga, somnolencia, euforia, vómitos, desorientación, confusión, pérdida del equilibrio, y alucinación.
CONCLUSIONES Y RELEVANCIA: Hubo evidencia de calidad moderada para apoyar el uso de los cannabinoides en el tratamiento del dolor crónico y la espasticidad. Hubo evidencia de baja calidad que sugiere que los cannabinoides se asociaron a mejoras en las náuseas y vómitos debido a quimioterapia, aumento de peso en la infección por el VIH, trastornos del sueño y síndrome de Tourette. Los cannabinoides se asociaron a un mayor riesgo de EAs a corto plazo.
Although many pharmacological agents are used in the therapy of neuropathic pain (NeP) due to polyneuropathy (PN), there are limited comparison studies comparing these agents. We evaluated patients with PN and related NeP in a tertiary care neuromuscular clinic with prospective follow-up after 3 and 6 months for degree of NeP using a Visual Analog Score (VAS). Clinical response to specific open-label pharmacotherapies was measured and compared for those patients not receiving pharmacotherapy. The severity of PN was quantified by the Toronto Clinical Scoring System (TCSS), with patients classified according to etiology of PN. Of a total of 408 patients referred for diagnosis and/or management of PN, NeP was identified in 182 patients (45%). NeP was most prevalent in patients with alcohol-associated PN. Pharmacotherapy management was provided in 91% of cases at first visit, and for 87% of cases after 6 months of follow-up. There were no serious adverse events for patients related to any medications, which included gabapentinoids, tricyclic antidepressants, anticonvulsants, cannabinoids and topical agents. Prevalence of intolerable side effects was similar amongst groups of medications. Approximated numbers needed to treat were similar between different individual oral pharmacotherapies, trending towards greater treatment efficacy with combination therapy. NeP is common in patients with PN and frequently requires pharmacotherapy management, which may be more effective with combination therapy. Future studies assessing longer duration of follow-up and quality of life changes with the use of various pharmacotherapies for management of NeP due to PN will be important.
INTRODUCTION: Despite the recent discovery of the potential mechanisms underlying the analgesic effects of cannabis, few clinical studies have so far assessed its analgesic effects, notably in the treatment of chronic non-malignant pain. All the studies used administration of cannabis alone. The aim of this open, pilot, study was to assess the efficacy and side effect profile of oral dronabinol (tetrahydrocannabinol - THC) in the treatment of refractory neuropathic pain.
METHODS: Seven patients (3 women/4 men), aged 60 +/- 14 years, suffering from chronic refractory neuropathic pain, received oral THC titrated to the maximum dose of 25 mg/day (mean dose: 15 +/- 6 mg), during an average of 55,4 days (range: 13-128). Various components of pain (continuous, paroxysmal and brush-induced allodynia) were assessed using VAS scores. Health-related Quality of Life (HRQL) was evaluated using the Brief Pain Inventory, and the Hospital Anxiety and Depression scale was used to measure depression and anxiety.
RESULTS: THC did not induce significant effect on the various pain, HRQL and anxiety and depression scores. Numerous side effects (notably sedation and asthenia) were observed in 5 patients out of 7, requiring premature discontinuation of the drug in 3 patients.
CONCLUSION: The present study did not reveal any significant efficacy of THC in a small cohort of patients with chronic refractory neuropathic pain, but underlined the unfavorable side effect profile of the drug. These results may partly relate to the fact that oral dronabinol exhibits a poor therapeutic ratio (efficacy at the price of side effects). The development of new and better tolerated cannabinoids is warranted.
Cannabis is increasingly available for the treatment of chronic pain, yet its efficacy remains uncertain.
PURPOSE:
To review the benefits of plant-based cannabis preparations for treating chronic pain in adults and the harms of cannabis use in chronic pain and general adult populations.
DATA SOURCES:
MEDLINE, Cochrane Database of Systematic Reviews, and several other sources from database inception to March 2017.
STUDY SELECTION:
Intervention trials and observational studies, published in English, involving adults using plant-based cannabis preparations that reported pain, quality of life, or adverse effect outcomes.
DATA EXTRACTION:
Two investigators independently abstracted study characteristics and assessed study quality, and the investigator group graded the overall strength of evidence using standard criteria.
DATA SYNTHESIS:
From 27 chronic pain trials, there is low-strength evidence that cannabis alleviates neuropathic pain but insufficient evidence in other pain populations. According to 11 systematic reviews and 32 primary studies, harms in general population studies include increased risk for motor vehicle accidents, psychotic symptoms, and short-term cognitive impairment. Although adverse pulmonary effects were not seen in younger populations, evidence on most other long-term physical harms, in heavy or long-term cannabis users, or in older populations is insufficient.
LIMITATION:
Few methodologically rigorous trials; the cannabis formulations studied may not reflect commercially available products; and limited applicability to older, chronically ill populations and patients who use cannabis heavily.
CONCLUSION:
Limited evidence suggests that cannabis may alleviate neuropathic pain in some patients, but insufficient evidence exists for other types of chronic pain. Among general populations, limited evidence suggests that cannabis is associated with an increased risk for adverse mental health effects.
