THC/CBD spray maintained pain relief for 38 weeks in neuropathic pain patients without dose escalation
In a 38-week follow-up of 380 neuropathic pain patients, THC/CBD spray maintained pain reduction from 6.9 to 4.2 on a 10-point scale, with 62% completing the study and no dose escalation over time.
Quick Facts
What This Study Found
This open-label extension study followed 380 patients with peripheral neuropathic pain (from diabetes or allodynia) who had participated in two prior randomized controlled trials of THC/CBD oromucosal spray. Patients received the spray for an additional 38 weeks alongside their current pain medications.
Pain scores on a 0-10 scale decreased from a mean of 6.9 at the original baseline to 4.2 at the end of the extension. At least half of patients reported a clinically meaningful 30% improvement at all time points, with the proportion continuing to increase up to 9 months. Improvements were also seen in sleep quality, neuropathic pain subscales, patient global impression of change, and quality of life.
Critically, patients did not seek to increase their dose over time, suggesting tolerance did not develop. The spray was well tolerated with no new safety concerns from long-term use.
Key Numbers
380 patients entered; 234 completed (62%). Pain NRS: 6.9 baseline to 4.2 at end. At least 50% had 30% improvement at all time points. 38 weeks of follow-up. No dose escalation observed.
How They Did This
Open-label, 38-week extension study of 380 patients from two parent randomized controlled trials. Patients had peripheral neuropathic pain from diabetes or allodynia. Primary outcome: 0-10 pain NRS. Secondary outcomes: sleep, neuropathic pain subscales, global impression, quality of life. Safety and dosing patterns tracked throughout.
Why This Research Matters
Long-term pain management data for cannabinoids is scarce. This study demonstrates that THC/CBD spray can maintain effectiveness for nearly a year without dose escalation, addressing concerns about tolerance that limit the long-term utility of many pain medications.
The Bigger Picture
Chronic pain management is a major clinical challenge, with many treatments losing effectiveness over time or requiring increasing doses. THC/CBD spray maintaining benefit without dose escalation for 38 weeks is clinically significant, particularly for a difficult-to-treat population.
What This Study Doesn't Tell Us
Open-label design means no placebo comparison for the extension phase. Patients who entered the extension were selected from prior RCTs (likely biased toward those who responded). 38% dropout rate may bias results toward better outcomes. Neuropathic pain from diabetes and allodynia may not represent all neuropathic pain types.
Questions This Raises
- ?Would the benefit persist beyond 38 weeks?
- ?Does the lack of dose escalation hold over years?
- ?How does THC/CBD spray compare to other long-term neuropathic pain treatments?
- ?Would patients with other types of neuropathic pain show similar benefit?
Trust & Context
- Key Stat:
- Pain reduced from 6.9 to 4.2/10 over 38 weeks without dose escalation
- Evidence Grade:
- Open-label extension study following RCTs. Good long-term data but lacks placebo comparison in the extension phase.
- Study Age:
- Published in 2015. Long-term data on THC/CBD spray has continued to accumulate.
- Original Title:
- A multicentre, open-label, follow-on study to assess the long-term maintenance of effect, tolerance and safety of THC/CBD oromucosal spray in the management of neuropathic pain.
- Published In:
- Journal of neurology, 262(1), 27-40 (2015)
- Authors:
- Hoggart, B, Ratcliffe, S(4), Ehler, E(2), Simpson, K H, Hovorka, J, Lejčko, J, Taylor, L, Lauder, H, Serpell, M
- Database ID:
- RTHC-00983
Evidence Hierarchy
Follows a group of people over time to track how outcomes develop.
What do these levels mean? →Frequently Asked Questions
Does THC/CBD spray lose effectiveness over time?
In this 38-week study, the spray maintained its pain-relieving effect without patients needing to increase their dose. The proportion reporting meaningful improvement continued to increase up to 9 months.
Is THC/CBD spray safe for long-term use?
Over 38 weeks, the spray was well tolerated with no new safety concerns. However, this was an open-label study without a long-term placebo comparison, so results should be interpreted with some caution.
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Cite This Study
https://rethinkthc.com/research/RTHC-00983APA
Hoggart, B; Ratcliffe, S; Ehler, E; Simpson, K H; Hovorka, J; Lejčko, J; Taylor, L; Lauder, H; Serpell, M. (2015). A multicentre, open-label, follow-on study to assess the long-term maintenance of effect, tolerance and safety of THC/CBD oromucosal spray in the management of neuropathic pain.. Journal of neurology, 262(1), 27-40. https://doi.org/10.1007/s00415-014-7502-9
MLA
Hoggart, B, et al. "A multicentre, open-label, follow-on study to assess the long-term maintenance of effect, tolerance and safety of THC/CBD oromucosal spray in the management of neuropathic pain.." Journal of neurology, 2015. https://doi.org/10.1007/s00415-014-7502-9
RethinkTHC
RethinkTHC Research Database. "A multicentre, open-label, follow-on study to assess the lon..." RTHC-00983. Retrieved from https://rethinkthc.com/research/hoggart-2015-a-multicentre-openlabel-followon
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.