Long-term Cannabis Spray for Cancer Pain: Sustained Benefit, No Tolerance
What Researchers Found About Cancer Pain and Cannabis
The Study at a Glance
Published
Journal of Pain and Symptom Management, 2013
Researchers
Multiple institutions (International)
Study Type
Observational StudyParticipants
43 patients · Long-term (open-label extension)
Key Finding
Long-term use of THC/CBD spray was generally well tolerated, with no evidence of a loss of effect for the relief of cancer-related pain with long-term use. Patients did not seek to increase their dose over time, suggesting no tolerance development.
Key Finding: Long-term use of THC/CBD spray was generally well tolerated, with no evidence of a loss of effect for the relief of cancer-related pain with long-term use. Patients did not seek to increase their dose over time, suggesting no tolerance development.
What Researchers Studied About Cancer Pain and Cannabis
Chronic pain in patients with advanced cancer poses a serious clinical challenge. THC/CBD oromucosal spray (nabiximols; Sativex) is a cannabinoid formulation being investigated as adjuvant therapy.
This follow-up study examined long-term safety and tolerability of THC/CBD spray in patients with cancer-related pain who had inadequate pain relief despite chronic opioid dosing.
43 patients who completed a previous randomized controlled trial entered this open-label, multicenter extension study.
How This Observational Study Was Conducted
Patients received THC/CBD spray (n=39) or THC spray (n=4) and self-titrated to symptom relief or maximum dose.
They were regularly reviewed for safety, tolerability, and evidence of clinical benefit.
Outcomes included Brief Pain Inventory-Short Form scores for pain severity and worst pain, and EORTC Quality of Life Questionnaire-C30 scores.
Cancer Pain Treatment Results
The Main Results:
- 1Pain severity and worst pain scores showed IMPROVEMENT at each visit with THC/CBD spray
- 2EORTC QoL scores showed IMPROVEMENT in insomnia, pain, and fatigue domains
- 3NO new safety concerns with extended use
- 4Patients did NOT seek to increase their dose of this or other pain medication over time
- 5No evidence of loss of effect (tolerance) with long-term use
- 6THC/CBD spray was generally well tolerated
By the Numbers
| Statistic | What It Means |
|---|---|
| 43 patients | Terminal cancer patients with pain refractory to opioids |
| No tolerance | Patients did not need to increase dose over time to maintain effect |
| Improved | Pain severity and worst pain scores improved at each visit |
| No new concerns | No new safety signals emerged with extended use |
Terminal cancer patients with pain refractory to opioids
Patients did not need to increase dose over time to maintain effect
Pain severity and worst pain scores improved at each visit
No new safety signals emerged with extended use
What This Means for Cancer Pain Patients
If you have cancer pain that is not adequately controlled by opioids, this study provides encouraging long-term data on THC/CBD spray (Sativex).
Over extended use, patients continued to experience pain relief without needing to increase their dose. This is particularly important because it suggests no tolerance development, a common concern with pain medications.
Pain severity improved at each follow-up visit, and quality of life measures for insomnia, pain, and fatigue also improved.
No new safety concerns emerged with long-term use, and the medication was generally well tolerated.
The fact that patients did not seek to increase their cannabinoid dose or their other pain medications over time is reassuring for long-term use as an adjuvant to opioid therapy.
Quick Answers: Cancer Pain and Cannabis
Direct answers based on the findings of this study:
Research Summary: Answers are based on published peer-reviewed studies and represent research findings, not medical recommendations. Individual results may vary. Always consult a healthcare provider before making treatment decisions.
Can you use cannabis long-term for cancer pain?
Yes. A long-term extension study of 43 cancer patients found THC/CBD spray maintained pain relief over time with no evidence of tolerance. Patients did not need to increase doses. No new safety concerns emerged.
Source: Johnson et al., J Pain Symptom Management, 2013 (PMID: 23141881)
Do you build tolerance to medical marijuana?
No tolerance development observed. Patients on long-term THC/CBD spray did not seek to increase their dose over time, suggesting no tolerance when cannabinoids are used as adjuvant therapy for cancer pain.
Source: Johnson et al., J Pain Symptom Management, 2013 (PMID: 23141881)
Does Sativex help cancer pain long-term?
Yes. In a long-term extension study, THC/CBD spray (Sativex) showed sustained benefit for cancer pain. Pain severity and worst pain scores improved at each visit, with no loss of effect over time.
Source: Johnson et al., J Pain Symptom Management, 2013 (PMID: 23141881)
This is educational content, not medical advice
The research summarized here is for informational purposes only. Individual results may vary, and what works in studies may not work the same way for everyone. Always consult with a qualified healthcare provider before making changes to your treatment plan or starting medical cannabis therapy.
Important Limitations
This study has some caveats to keep in mind when interpreting the results:
- Open-label design (no placebo comparison in extension)
- Small sample size (43 patients)
- Patients had already responded in parent trial (selection bias)
- Terminal cancer population may limit generalizability
- Specific to THC/CBD oromucosal spray formulation
The Bottom Line on Cannabis for Cancer Pain
This long-term extension study of 43 cancer patients found THC/CBD spray provided sustained pain relief without loss of effect over time. Pain and quality of life measures improved at each visit. Critically, patients did not seek to increase their dose, suggesting no tolerance development. No new safety concerns emerged. This supports adjuvant cannabinoid use for cancer pain not controlled by opioids.
Do You Qualify for Medical Marijuana?
If you're living with Cancer Pain, you may qualify for a medical marijuana card. Our licensed physicians can evaluate you from home via telehealth.
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Source
Johnson JR, Lossignol D, Burnell-Nugent M, et al. "An open-label extension study to investigate the long-term safety and tolerability of THC/CBD oromucosal spray and oromucosal THC spray in patients with terminal cancer-related pain refractory to strong opioid analgesics" Journal of Pain and Symptom Management. 2013. DOI: 10.1016/j.jpainsymman.2012.07.014
Important Information
Study Age: This study was published 13 years ago. Newer research may have updated or refined these findings.
Not Medical Advice: This research summary is for educational purposes only. It should not be used to diagnose, treat, cure, or prevent any disease or medical condition. Always consult a qualified healthcare provider before starting or changing any treatment.
Individual Variation: Research findings represent group averages. Your individual response to cannabis may differ based on genetics, other medications, underlying conditions, and many other factors.
Last reviewed: January 25, 2026
Important Notices
Research Summary Disclaimer
This content represents our interpretation of published scientific research for educational purposes. It should not be used to make treatment decisions without consulting a qualified healthcare provider. Individual results may vary from study findings.
FDA Notice
These statements have not been evaluated by the FDA. Cannabis is not intended to diagnose, treat, cure, or prevent any disease. The FDA has not approved cannabis for any medical condition except specific prescription medications.
Copyright & Fair Use
Research summaries are provided under fair use (17 U.S.C. § 107) for educational purposes. We provide brief summaries with attribution, not full reproductions. All studies remain the intellectual property of their respective authors and publishers.
Data Sources
Study information sourced from PubMed®, U.S. National Library of Medicine. Inclusion does not imply endorsement by NLM, NIH, or the federal government.
For complete information, see our Terms of Use and Research Content Policy.
FAQs: Cannabis for Cancer Pain
Does cannabis keep working for cancer pain over time?
Yes. In this long-term study, THC/CBD spray maintained its pain-relieving effect without loss of efficacy. Patients did not need to increase their dose over time, suggesting no tolerance development.
Do you develop tolerance to cannabis for pain?
No tolerance development observed. Patients did not seek to increase their dose of THC/CBD spray or their other pain medications over time, suggesting adjuvant cannabinoid use does not lead to tolerance.
Is long-term cannabis safe for cancer patients?
Safe and well tolerated long-term. No new safety concerns emerged with extended THC/CBD spray use. Quality of life measures for insomnia, pain, and fatigue all improved.