Clinical Use of Cannabinoids for Symptom Control in Multiple Sclerosis.

The endocannabinoid system was discovered in 1988 but has received little attention for its potential therapeutic possibilities. That has started to change, and since 2000, a significant number of clinical trials of cannabinoids, principally for the control of spasticity in multiple sclerosis, have been undertaken. These studies have been difficult because of the nature of the disease and have involved patients for whom other therapies have failed or proved inadequate. This paper outlines the background to the use of cannabinoids available and discusses the principles of practice associated with their safe use. The focus has been on nabiximols, being the most studied and the only cannabinoid that has been both adequately researched for use in multiple sclerosis and granted a license by the regulators. However, what has emerged is that the effect for many patients can be much wider than just control of spasticity. Within and outside of neurology there seems to be an expanding range of possibilities for the therapeutic use of cannabinoids.

Cannabidiol: pharmacology and potential therapeutic role in epilepsy and other neuropsychiatric disorders.

To present a summary of current scientific evidence about the cannabinoid, cannabidiol (CBD) with regard to its relevance to epilepsy and other selected neuropsychiatric disorders. We summarize the presentations from a conference in which invited participants reviewed relevant aspects of the physiology, mechanisms of action, pharmacology, and data from studies with animal models and human subjects. Cannabis has been used to treat disease since ancient times. Δ(9) -Tetrahydrocannabinol (Δ(9) -THC) is the major psychoactive ingredient and CBD is the major nonpsychoactive ingredient in cannabis. Cannabis and Δ(9) -THC are anticonvulsant in most animal models but can be proconvulsant in some healthy animals. The psychotropic effects of Δ(9) -THC limit tolerability. CBD is anticonvulsant in many acute animal models, but there are limited data in chronic models. The antiepileptic mechanisms of CBD are not known, but may include effects on the equilibrative nucleoside transporter; the orphan G-protein-coupled receptor GPR55; the transient receptor potential of vanilloid type-1 channel; the 5-HT1a receptor; and the α3 and α1 glycine receptors. CBD has neuroprotective and antiinflammatory effects, and it appears to be well tolerated in humans, but small and methodologically limited studies of CBD in human epilepsy have been inconclusive. More recent anecdotal reports of high-ratio CBD:Δ(9) -THC medical marijuana have claimed efficacy, but studies were not controlled. CBD bears investigation in epilepsy and other neuropsychiatric disorders, including anxiety, schizophrenia, addiction, and neonatal hypoxic-ischemic encephalopathy. However, we lack data from well-powered double-blind randomized, controlled studies on the efficacy of pure CBD for any disorder. Initial dose-tolerability and double-blind randomized, controlled studies focusing on target intractable epilepsy populations such as patients with Dravet and Lennox-Gastaut syndromes are being planned. Trials in other treatment-resistant epilepsies may also be warranted. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here.

Sativex long-term use: an open-label trial in patients with spasticity due to multiple sclerosis.

Sativex is an endocannabinoid system modulator principally containing Δ(9)-tetrahydrocannabinol (THC) and cannabidiol (CBD). During a 6-week randomised controlled trial, Sativex had a clinically relevant effect on spasticity associated with multiple sclerosis (MS). Patients self-titrated oromucosal Sativex to symptom relief or maximum tolerated dose (maximum of 130 mg THC and 120 mg CBD daily). The primary objective was to evaluate the safety and tolerability of long-term treatment by recording the incidence and severity of adverse events (AEs). Secondary outcomes were to determine evidence of developing tolerance and to assess the long-term dosing profile of Sativex. A validated 11-point Numerical Rating Scale of spasticity severity was used to assess efficacy. A total of 146 patients elected to enter this open-label follow-up safety trial. Mean treatment exposure was 334 days (standard deviation, SD = 209 days), and patients administered on average 7.3 (SD = 4.42) actuations per day. Fifty-two (36 %) patients withdrew from the study in the first year, 14 % due to AEs and 9 % due to lack of efficacy. Most AEs were mild/moderate in severity. Common (>10 %) treatment-related AEs were dizziness (24.7 %) and fatigue (12.3 %). Serious AEs occurred in five patients (3.4 %), with two psychiatric events reported by one patient. No psychoses, psychiatric AE trends, or withdrawal symptoms occurred following abrupt cessation of treatment. Baseline symptoms including spasticity did not deteriorate but were maintained to study completion in those patients who did not withdraw. No new safety concerns were identified with chronic Sativex treatment, and serious AEs were uncommon. There was no evidence of tolerance developing, and patients who remained in the study reported continued benefit.

A questionnaire survey of patients and carers of patients prescribed Sativex as an unlicensed medicine.

AIM: To identify the areas of daily function most affected by the introduction of Sativex, a cannabis-based medicine, and the impact on caregivers and people with multiple sclerosis (MS). BACKGROUND: Cannabinoid medicines have recently become available on prescription in several parts of the world, principally for the treatment of spasticity in people with MS. Their efficacy and safety have been demonstrated in the setting of randomised controlled clinical trials. Results of such studies may not always reflect the wider effectiveness that a medicine shows when used in clinical practice. METHODS: A short questionnaire survey consisting mostly of multiple-choice questions, along with some free-text questions aimed at the patient and primary caregiver (ie, partner, mother, nurse or outside carer). The questionnaire was developed in consultation with a patient representative organisation, field tested, ethics approval gained, then distributed to prescribers in the United Kingdom, with the request that they in turn forward it to any patients who had received repeat prescriptions for Sativex within the previous 16 weeks. Patients were seen in both a primary care (general practice) and a secondary care (hospital) setting. There was no control group in this study. Most patients had MS, and the primary reasons for using Sativex were spasticity and pain. FINDINGS: The response rate was 57%, with 124 questionnaires returned. The majority of respondents and their caregivers reported improvements across a range of daily functional activities, alongside a reduction in the use of concomitant anti-spasticity medication and in the use of other healthcare resources.

Inadequate pain management: myth, stigma and professional fear.

The ability to effectively relieve pain has been available to health professionals for generations. It should be a primary concern in treating patients but is still often given a low priority or ignored completely. Apathy toward the suffering experienced may be mixed with a fear of the use of the common analgesics. Our own prejudices and ignorance can also contribute. Failures in the primary education of health professionals may be the single most important cause and the identity of the remedy. Raising the profile of pain as an essential educational topic and, more broadly, realising that this is a major public health matter are the way forward.

Initial experiences with medicinal extracts of cannabis for chronic pain: results from 34 'N of 1' studies.

Three Cannabis Based Medicinal Extracts (CBMEs) for sublingual use became available in 2000. A total of 34 'N of 1' studies were undertaken using this novel therapy for patients with chronic, mainly neuropathic, pain and associated symptoms to explore efficacy, tolerability, safety and dosages. Three CBMEs (Delta9 Tetrahydrocannabinol (THC), Cannabidiol (CBD) and a 1:1 mixture of them both) were given over a 12-week period. After an initial open-label period, the CBMEs were used in a randomised, double-blind, placebo controlled, crossover trial. Extracts which contained THC proved most effective in symptom control. Regimens for the use of the sublingual spray emerged and a wide range of dosing requirements was observed. Side-effects were common, reflecting a learning curve for both patient and study team. These were generally acceptable and little different to those seen when other psycho-active agents are used for chronic pain. These initial experiences with CBME open the way to more detailed and extensive studies.

A method for comparing endotracheal cuffs: a controlled study of tracheal trauma in dogs

Damage to the trachea produced in dogs by large and small residual volume cuffs during 6 h of IPPV was compared using a specifically designed endotracheal tube. The cuffs under evaluation were adjusted to exert similar average pressures on the tracheal walls, so that many of the variables believed responsible for tracheal injury were controlled. The tube compliance of the cuff was measured with tube inside and outside the trachea of the anesthetized dogs. The maximum estimated pressure transmitted to the tracheal wall, derived from these compliance curves, was found to equal the peak airway pressure in the presence of a small air leak past each cuff. At various tracheal wall pressures there were only minor differences in tracheal damage between the large and small residual volume cuffs tested (AU).