Sativex Was Safe and Effective for MS Spasticity Over Nearly a Year With No Tolerance Development
In a long-term safety trial of 146 MS patients using Sativex for an average of 334 days, no tolerance developed, serious adverse events were rare, and spasticity benefits were maintained without dose escalation.
Quick Facts
What This Study Found
One hundred forty-six MS patients entered an open-label follow-up of Sativex for spasticity. Mean treatment duration was 334 days, with an average of 7.3 sprays per day. Fifty-two patients (36%) withdrew in the first year, with 14% due to adverse events and 9% due to lack of efficacy.
Common treatment-related adverse events were dizziness (24.7%) and fatigue (12.3%), mostly mild to moderate. Serious adverse events occurred in only 5 patients (3.4%), with 2 psychiatric events in one patient. No psychoses, psychiatric trends, or withdrawal symptoms were observed upon abrupt cessation. Spasticity did not deteriorate over time, and patients reported continued benefit. No evidence of tolerance developing was found.
Key Numbers
146 patients entered. Mean exposure: 334 days. Mean dose: 7.3 sprays/day. 36% withdrew (14% AEs, 9% lack efficacy). Common AEs: dizziness 24.7%, fatigue 12.3%. Serious AEs: 3.4%. No psychosis, no tolerance, no withdrawal on cessation.
How They Did This
Open-label safety follow-up trial. 146 MS patients entering from a prior 6-week RCT. Self-titrated Sativex dosing. Primary outcome: safety and tolerability (AE incidence and severity). Secondary outcomes: tolerance development and dosing profile. NRS spasticity scale for efficacy.
Why This Research Matters
This study addresses three major concerns about long-term cannabinoid use: tolerance, psychosis risk, and dependence. All three were absent over nearly a year of treatment. For clinicians considering Sativex for their MS patients, these safety data are reassuring.
The Bigger Picture
This study provides the longest-duration safety data for Sativex at the time. The combination of maintained efficacy, no tolerance, no psychosis, and no dependence provides a comprehensive safety profile that supports the viability of long-term cannabinoid therapy for MS spasticity.
What This Study Doesn't Tell Us
Open-label design with no placebo comparison. Only patients who chose to continue from the parent trial were included, introducing selection bias. The 36% withdrawal rate means the long-term data represents completers only. Psychiatric events in one patient (2 events) may be underrepresented.
Questions This Raises
- ?Would these safety findings hold over multiple years?
- ?What distinguishes the 64% who continued from the 36% who withdrew?
- ?Is the lack of tolerance specific to the Sativex formulation or common to all cannabinoid medicines?
Trust & Context
- Key Stat:
- No tolerance, no psychosis, no withdrawal symptoms over an average of 334 days
- Evidence Grade:
- Open-label safety trial with adequate duration; moderate evidence for long-term safety and maintained efficacy.
- Study Age:
- Published in 2013. Sativex has accumulated additional long-term safety data since.
- Original Title:
- Sativex long-term use: an open-label trial in patients with spasticity due to multiple sclerosis.
- Published In:
- Journal of neurology, 260(1), 285-95 (2013)
- Authors:
- Serpell, Michael G, Notcutt, William(2), Collin, Christine
- Database ID:
- RTHC-00733
Evidence Hierarchy
Watches what happens naturally without intervening.
What do these levels mean? →Frequently Asked Questions
Is Sativex safe to use long-term?
In this trial averaging nearly a year of use, Sativex was generally well tolerated. Most side effects were mild (dizziness, fatigue). Serious adverse events were rare (3.4%). No cases of psychosis or addiction were observed, and there were no withdrawal symptoms when patients stopped. However, 36% withdrew in the first year, some due to side effects.
Will I need to keep increasing the dose?
No. This study found no evidence of tolerance developing. Patients maintained a stable average dose of 7.3 sprays per day throughout the study, and their spasticity did not worsen over time. This means the effectiveness was sustained without needing dose increases.
Read More on RethinkTHC
- CBD-oil-quality-guide
- anxiety-medication-after-quitting-weed
- cannabis-chemotherapy-nausea
- cannabis-chronic-pain-research
- cannabis-epilepsy-CBD-Epidiolex
- cbd-anxiety-research-evidence
- cbd-for-weed-withdrawal
- cbd-vs-thc-difference
- medical-benefits-of-cannabis
- quitting-weed-before-surgery
- quitting-weed-medication-interactions
- quitting-weed-pregnancy
- quitting-weed-pregnant
- seniors-older-adults-cannabis-risks-medications
- weed-breastfeeding-THC-breast-milk
Cite This Study
https://rethinkthc.com/research/RTHC-00733APA
Serpell, Michael G; Notcutt, William; Collin, Christine. (2013). Sativex long-term use: an open-label trial in patients with spasticity due to multiple sclerosis.. Journal of neurology, 260(1), 285-95. https://doi.org/10.1007/s00415-012-6634-z
MLA
Serpell, Michael G, et al. "Sativex long-term use: an open-label trial in patients with spasticity due to multiple sclerosis.." Journal of neurology, 2013. https://doi.org/10.1007/s00415-012-6634-z
RethinkTHC
RethinkTHC Research Database. "Sativex long-term use: an open-label trial in patients with ..." RTHC-00733. Retrieved from https://rethinkthc.com/research/serpell-2013-sativex-longterm-use-an
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.