Medical cannabis improved pain in fibromyalgia patients who failed other treatments

In 38 fibromyalgia patients resistant to conventional therapy, medical cannabis significantly improved pain and disability scores, though nearly half discontinued due to non-serious side effects like mental confusion.

Mazza, Manuela·Journal of cannabis research·2021·Preliminary EvidenceCase Report
RTHC-03331Case ReportPreliminary Evidence2021RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Case Report
Evidence
Preliminary Evidence
Sample
N=38

What This Study Found

Significant improvements (P < 0.01) were observed in pain scores (NRS), disability (ODI), widespread pain (WPI), and symptom severity (SyS) at various time points up to 12 months. However, 17 patients (48.6%) discontinued due to non-serious adverse effects including mental confusion (37%), dizziness (14%), nausea/vomiting (14%), and restlessness (14%).

Key Numbers

38 patients; 30 at 1 month, 18 at 3 months, 12 at 12 months; 48.6% discontinued due to AEs; mental confusion 37%; median THC dose 46.2 mg (dominant) or 23.6 mg THC + 38 mg CBD (hybrid) at 3 months

How They Did This

Retrospective, open-label case series of 38 fibromyalgia patients resistant to conventional therapy at an Italian pain clinic. Patients received licensed medical cannabis as powdered flowers or oil extracts with various THC/CBD ratios. Outcomes measured at 1, 3, and 12 months.

Why This Research Matters

Fibromyalgia is notoriously difficult to treat, and patients who fail conventional therapy have few options. This series provides real-world data on both the potential benefits and the significant tolerability challenges of medical cannabis in this population.

The Bigger Picture

The tension between meaningful symptom improvement and a nearly 50% dropout rate due to side effects highlights the challenge of medical cannabis for fibromyalgia. Finding the right dosing and formulation to maximize benefit while minimizing cognitive side effects remains critical.

What This Study Doesn't Tell Us

No control group or blinding. High dropout rate limits interpretation of long-term results. Retrospective design. Small sample. Italian regulatory context may affect product availability and dosing.

Questions This Raises

  • ?Would lower doses or different THC:CBD ratios reduce the dropout rate while preserving benefits?
  • ?Are the patients who tolerated cannabis long-term fundamentally different from those who dropped out?
  • ?How does this compare to other treatments for treatment-resistant fibromyalgia?

Trust & Context

Key Stat:
48.6% discontinued due to side effects, mostly mental confusion
Evidence Grade:
Small open-label case series without a control group, though it provides real-world data on a treatment-resistant population.
Study Age:
Published in 2021.
Original Title:
Medical cannabis for the treatment of fibromyalgia syndrome: a retrospective, open-label case series.
Published In:
Journal of cannabis research, 3(1), 4 (2021)
Database ID:
RTHC-03331

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / Observational
Case Report / Animal StudyOne case or non-human subjects
This study

Describes what happened to one person or a small group.

What do these levels mean? →

Frequently Asked Questions

How effective was medical cannabis for fibromyalgia?

Pain and disability scores improved significantly in patients who stayed on treatment. However, nearly half of patients stopped due to side effects, so the benefits may be limited to those who can tolerate the medication.

What were the most common side effects?

Mental confusion was the most common at 37%, followed by dizziness (14%), nausea/vomiting (14%), and restlessness/irritation (14%). All were classified as non-serious.

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Cite This Study

RTHC-03331·https://rethinkthc.com/research/RTHC-03331

APA

Mazza, Manuela. (2021). Medical cannabis for the treatment of fibromyalgia syndrome: a retrospective, open-label case series.. Journal of cannabis research, 3(1), 4. https://doi.org/10.1186/s42238-021-00060-6

MLA

Mazza, Manuela. "Medical cannabis for the treatment of fibromyalgia syndrome: a retrospective, open-label case series.." Journal of cannabis research, 2021. https://doi.org/10.1186/s42238-021-00060-6

RethinkTHC

RethinkTHC Research Database. "Medical cannabis for the treatment of fibromyalgia syndrome:..." RTHC-03331. Retrieved from https://rethinkthc.com/research/mazza-2021-medical-cannabis-for-the

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.