What does the evidence say about cannabis in palliative care? | Research

The takeaway

A systematic review of 52 studies found some positive effects of cannabis products on pain, nausea, appetite, and sleep in palliative care patients, but the overall evidence quality was very low to low.

Palliative care clinicians, patients, and researchers interested in cannabis for symptom management.

52 studies, 4,786 patients, but all evidence rated low or very low quality

What the researchers found

Across 52 studies with 4,786 participants, some cannabis products showed positive effects on pain, nausea/vomiting, appetite, sleep, fatigue, and night sweats in cancer patients; appetite and agitation in dementia patients; and appetite and nausea in AIDS patients. However, all evidence was rated very low or low quality.

Why it matters

Palliative care patients often use cannabis for symptom management, but clinicians lack high-quality evidence to guide recommendations.

The numbers in context

52 studies (20 randomized, 32 non-randomized), 4,786 participants. Cancer: 4,491 patients. AIDS: 235. Dementia: 43. Spasticity: 16. All evidence rated "very low" or "low" quality.

How the study worked

Systematic review searching PubMed, Embase, Cochrane, and ClinicalTrials.gov from 1960 to September 2021. Quality assessed using GRADE. Risk of bias evaluated with RoB 2 (RCTs) and ROBINS-I (non-randomized studies). Meta-analysis was not possible due to heterogeneity.

What this study cannot tell us

All evidence was very low or low quality. Wide variation in cannabis products, doses, and outcome measures prevented meta-analysis. Most participants had cancer, limiting generalizability to other conditions.

How to read the evidence

Comprehensive systematic review, but the underlying studies were all very low or low quality by GRADE criteria.

When this study was published

Published in 2022 with studies searched through September 2021.

The bigger picture

The wide range of cannabis products used across studies and heterogeneous outcomes made meta-analysis impossible, highlighting the need for standardized research in this field.

Questions still open

Which specific cannabis formulations are most effective for which palliative symptoms? Would standardized dosing protocols improve evidence quality in future studies?

Common questions

Did cannabis help with pain in palliative care?

Some studies found positive effects on pain in cancer patients, but the evidence quality was rated very low or low, meaning these findings need confirmation from better-designed studies.

Why couldn't the researchers combine the results statistically?

The studies used such a wide range of different cannabis products, doses, and ways of measuring outcomes that combining them in a meta-analysis was not meaningful.

Read the original research

Cannabis in Palliative Care: A Systematic Review of Current Evidence.

Journal of pain and symptom management, 64(5), e260-e284

View on PubMed ↗Publisher’s paper ↗

Citation

Doppen, Marjan; Kung, Stacey; Maijers, Ingrid; John, Mary; Dunphy, Harriette; Townsley, Hermaleigh; Eathorne, Allie; Semprini, Alex; Braithwaite, Irene. (2022). Cannabis in Palliative Care: A Systematic Review of Current Evidence.. Journal of pain and symptom management, 64(5), e260-e284. https://doi.org/10.1016/j.jpainsymman.2022.06.002