First large Italian study of cannabis for chronic pain found 76% of patients continued treatment after initial follow-up | Research

The takeaway

Among 614 Italian chronic pain patients treated with cannabis (primarily as tea), 76.2% continued treatment at initial follow-up, and fewer than 15% stopped due to side effects, none of which were severe.

Read this if you want to see real-world outcomes of medical cannabis for chronic pain in a clinical setting.

76.2% of patients continued cannabis treatment; <15% stopped due to side effects

What the researchers found

Following Italy's 2015 authorization of medical cannabis, researchers analyzed the first year of clinical use for chronic pain across six treatment centers. Only one center (Pisa) had extensive experience, treating 614 of 659 total patients.

Cannabis tea was the primary delivery method, and in nearly all cases, cannabis was used alongside existing pain treatments rather than as a replacement. Initial and follow-up cannabinoid concentrations varied considerably across patients.

At the first follow-up, 76.2% of patients continued treatment. Fewer than 15% discontinued due to side effects, and none of the side effects were severe.

Why it matters

This is the first large-scale snapshot of real-world cannabis use for chronic pain in Italy, providing data from a clinical setting rather than a controlled trial. The high continuation rate and low rate of severe side effects suggest acceptable tolerability in a diverse chronic pain population.

The numbers in context

614 patients from Pisa center (of 659 total across six centers). 76.2% continued treatment at initial follow-up. <15% stopped due to side effects (none severe). Primary delivery: cannabis tea. Treatment period: December 2015-November 2016.

How the study worked

Retrospective case series analyzing all chronic pain patients treated with oral or vaporized cannabis at six Italian centers from December 2015 to November 2016. Evaluated routes of administration, cannabis products used, dosing, effectiveness, and safety.

What this study cannot tell us

Retrospective, uncontrolled case series with no placebo comparison. Continuation rate does not equal efficacy. Concentration variability limits reproducibility. Only one center contributed the vast majority of patients. Pain type heterogeneity makes it difficult to identify which conditions respond best. Short follow-up period.

How to read the evidence

Large retrospective case series providing real-world data. No control group or standardized outcomes limit the strength of conclusions.

When this study was published

Published in 2017. Italy's medical cannabis program has continued to evolve with accumulating clinical experience.

The bigger picture

Italy's approach of authorizing cannabis through clinical centers rather than dispensaries created an opportunity to systematically track patient outcomes. The high continuation rate is encouraging, though it could reflect patient self-selection or placebo effects. The variability in cannabinoid concentrations highlights the need for standardization.

Questions still open

Which specific chronic pain conditions responded best to cannabis treatment? Would standardized dosing improve outcomes? How do the Italian results compare to similar programs in other countries?

Common questions

How was the cannabis administered?

The primary method was cannabis tea, and in nearly all cases it was used alongside existing pain medications rather than as a standalone treatment. This reflects a conservative clinical approach of adding cannabis to existing regimens.

Does 76% continuation mean it works?

Not necessarily. Continuation rate indicates tolerability and perceived benefit, but without a control group, placebo effects, natural symptom fluctuation, and patient expectations cannot be separated from actual drug effect.

Read the original research

Cannabis and intractable chronic pain: an explorative retrospective analysis of Italian cohort of 614 patients.

Journal of pain research, 10, 1217-1224

View on PubMed ↗Publisher’s paper ↗

Citation

Fanelli, Guido; De Carolis, Giuliano; Leonardi, Claudio; Longobardi, Adele; Sarli, Ennio; Allegri, Massimo; Schatman, Michael E. (2017). Cannabis and intractable chronic pain: an explorative retrospective analysis of Italian cohort of 614 patients.. Journal of pain research, 10, 1217-1224. https://doi.org/10.2147/JPR.S132814