Cannabis as a Complementary Treatment in Multiple Sclerosis

The aim of this study is to document, 1. The efficacy of THC and CBD, alone and in combination, as add-on therapies to the current standard treatments for relief of spasticity and other symptoms in PwMS (muscle spasms and stiffness); 2. Assess the tolerability profile of THC and CBD, alone and in combination, when used in PwMS; 3. Identify the mechanisms underlying such therapeutic and adverse effects of different types of cannabis-based medicines in PwMS, Participants will initially receive THC 4mg/day or CBD 40mg/day or THC/CBD combination (THC 4mg and CBD 40mg/day), or placebo, on the first day. Dose will be increased up to 20mg (THC) and 200mg (CBD) per day, if well tolerated. Participants will receive the allocated treatment for a total of 4 weeks, followed by an additional 12 weeks of treatment for responders who will be identified as patients who had a decrease from baseline in spasticity of at least one point on the Numerical Rating Scale . THC and CBD will be taken as oil softgels in two divided doses per day. Cannabis extract and placebo will taste and look exactly the same. To protect from all contingencies and to minimize the risk of adverse reactions, the presence of adverse events will be evaluated at each research visit, as well as through courtesy calls between visits. If any mental or physical symptoms occur that require medical attention, the PwMS will be referred as required to an attending neurologist, psychiatrist, or other specialists .