Article Text

Research paper
MUltiple Sclerosis and Extract of Cannabis: results of the MUSEC trial
  1. John Peter Zajicek1,
  2. Jeremy C Hobart1,
  3. Anita Slade1,
  4. David Barnes2,
  5. Paul G Mattison3,
  6. on behalf of the MUSEC Research Group
  1. 1Clinical Neurology Research Group, Peninsula College of Medicine and Dentistry, University of Plymouth, Derriford, UK
  2. 2Department of Neurology, St George's Healthcare NHS Trust, London, UK
  3. 3Multiple Sclerosis Service, Ayrshire Central Hospital, Irvine, Ayrshire, UK
  1. Correspondence to Professor J P Zajicek, Peninsula College of Medicine and Dentistry, University of Plymouth, Clinical Neurology Research Group, TSP, ITTC Building 1, Derriford, PL6 8BX, UK; john.zajicek{at}


Objective Multiple sclerosis (MS) is associated with chronic symptoms, including muscle stiffness, spasms, pain and insomnia. Here we report the results of the Multiple Sclerosis and Extract of Cannabis (MUSEC) study that aimed to substantiate the patient based findings of previous studies.

Patients and methods Patients with stable MS at 22 UK centres were randomised to oral cannabis extract (CE) (N=144) or placebo (N=135), stratified by centre, walking ability and use of antispastic medication. This double blind, placebo controlled, phase III study had a screening period, a 2 week dose titration phase from 5 mg to a maximum of 25 mg of tetrahydrocannabinol daily and a 10 week maintenance phase. The primary outcome measure was a category rating scale (CRS) measuring patient reported change in muscle stiffness from baseline. Further CRSs assessed body pain, spasms and sleep quality. Three validated MS specific patient reported outcome measures assessed aspects of spasticity, physical and psychological impact, and walking ability.

Results The rate of relief from muscle stiffness after 12 weeks was almost twice as high with CE than with placebo (29.4% vs 15.7%; OR 2.26; 95% CI 1.24 to 4.13; p=0.004, one sided). Similar results were found after 4 weeks and 8 weeks, and also for all further CRSs. Results from the MS scales supported these findings.

Conclusion The study met its primary objective to demonstrate the superiority of CE over placebo in the treatment of muscle stiffness in MS. This was supported by results for secondary efficacy variables. Adverse events in participants treated with CE were consistent with the known side effects of cannabinoids. No new safety concerns were observed.

Trial registration number NCT00552604.

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Supplementary materials

  • John Zajicek talks to editor Matthew Kiernan about the research in the JNNP podcast

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  • See appendix for list of investigators of the MUSEC Research Group.

  • Funding Funded by the Society for Clinical Research, Berlin, Germany, and Weleda AG, Arlesheim, Switzerland.

  • Competing interests JPZ has received consultancy fees from IKF and Bayer-Schering. He has received funding from the MRC and NIHR EME to conduct studies using cannabinoids. He is a named inventor in two patents regarding cannabinoid use in multiple sclerosis. JCH has received honoraria, consulting fees or, support for conferences from, or contributions towards research from Acorda, Biogen Idec, Merck Serono, Bayer Schering, Teva and MAPI industries.

  • Ethics approval Ethics approval was provided by Scotland A Research Ethics Committee.

  • Provenance and peer review Not commissioned; externally peer reviewed.