Pilot test of whether cannabis extract helps breathlessness in COPD patients | Research

The takeaway

In a tiny pilot study, sublingual cannabis extract did not change standard breathlessness scores but COPD patients described the sensation of "air hunger" less often.

Read this if you have COPD and are curious about cannabis for breathlessness.

9 subjects total in this pilot study

What the researchers found

Nine subjects (five healthy, four with COPD) received sublingual cannabis extract or placebo in a crossover design. Standard breathlessness measurements using visual analogue scales showed no differences between drug and placebo in either group.

However, when COPD patients were asked to describe their breathlessness using specific descriptors, those who received the cannabis extract chose "air hunger" less frequently compared to placebo. This suggested the drug might change the qualitative experience of breathlessness without altering its perceived intensity.

The study found no respiratory depression with cannabis extract, supporting the hypothesis that cannabinoids could ease breathlessness sensation without suppressing breathing.

Why it matters

Breathlessness in COPD is difficult to treat. If cannabinoids can change the subjective quality of breathlessness without suppressing respiratory drive, they could fill a treatment gap where opioids carry respiratory depression risk.

The numbers in context

9 total subjects (5 normal, 4 COPD). Maximum dose: 10.8 mg THC and 10 mg CBD sublingual. Measurements taken at baseline and 2 hours post-administration.

How the study worked

Double-blind, randomized, placebo-controlled crossover study with two test days. Five normal subjects and four COPD subjects received sublingual cannabis extract (up to 10.8 mg THC and 10 mg CBD) or placebo. Breathlessness was induced using fixed carbon dioxide loads.

What this study cannot tell us

Extremely small sample size (only 4 COPD patients). Single-dose design. The carbon dioxide challenge may not adequately replicate real-world breathlessness experiences. The study was underpowered to detect meaningful differences.

How to read the evidence

Pilot RCT with only 9 subjects total. Too small to draw firm conclusions but useful for generating hypotheses and testing safety.

When this study was published

Published in 2011. Larger trials on cannabinoids for COPD breathlessness have not materialized in the years since.

The bigger picture

This pilot suggested that standard breathlessness rating scales might miss drug effects that breathlessness descriptors can detect. The finding has implications for how future breathlessness studies are designed, not just for cannabinoid research.

Questions still open

Would repeated dosing show stronger effects? Can breathlessness descriptors be validated as primary outcomes in larger trials? What cannabinoid receptor mechanisms underlie changes in breathlessness perception?

Common questions

Did the cannabis extract help people breathe easier?

Standard breathlessness scores showed no improvement. But COPD patients described the unpleasant "air hunger" sensation less often after the cannabis extract, suggesting it may change how breathlessness feels rather than how severe it is.

Did cannabis suppress breathing?

No. Ventilatory parameters were not affected, meaning the cannabis extract did not cause respiratory depression in this small group.

Read the original research

Cannabinoid effects on ventilation and breathlessness: a pilot study of efficacy and safety.

Chronic respiratory disease, 8(2), 109-18

View on PubMed ↗Publisher’s paper ↗

Citation

Pickering, Elspeth E; Semple, Stephen J; Nazir, Muhummad S; Murphy, Kevin; Snow, Thomas M; Cummin, Andrew R; Moosavi, Shakeeb H; Guz, Abraham; Holdcroft, Anita. (2011). Cannabinoid effects on ventilation and breathlessness: a pilot study of efficacy and safety.. Chronic respiratory disease, 8(2), 109-18. https://doi.org/10.1177/1479972310391283