Cannabinoid Medicines Are Generally Safe for Older Adults, With Dose-Dependent Side Effects | Research

The takeaway

A meta-analysis of 58 RCTs found THC-containing cannabinoid medicines increase common side effects (dry mouth, dizziness, drowsiness) in a dose-dependent manner in adults 50+, but serious adverse events, withdrawals, and deaths were not significantly higher than controls.

Geriatricians, older adults considering cannabis, and prescribing clinicians

No significant increase in serious adverse events or deaths in 50+ adults

What the researchers found

THC alone and THC:CBD combinations significantly increased all-cause and treatment-related adverse events compared to controls. However, serious adverse events, study withdrawals, and deaths were not significantly increased. THC dose-dependently increased dry mouth, dizziness, balance problems, dissociative/thinking issues, and drowsiness. The interaction of THC:CBD doses influenced neurological, psychiatric, and cardiac side effects.

Why it matters

Older adults are the fastest-growing demographic of cannabinoid medicine users, yet most safety data comes from younger populations. This meta-analysis specifically addresses the 50+ age group, providing age-appropriate safety data for clinical decision-making.

The numbers in context

58 RCTs, 6,611 participants, mean age 50-87. THC alone IRD for all AEs: 18.83 (CI: 1.47-55.79). THC:CBD IRD: 19.37 (CI: 4.24-45.47). No significant increase in serious AEs, withdrawals, or deaths. Dose-dependent: dry mouth, dizziness, balance, dissociative symptoms, drowsiness.

How the study worked

Systematic review and meta-analysis of 58 RCTs (37 moderate-high quality) with pooled n=6,611 participants (mean age 50-87 years, 50% male, 3,450 receiving CBMs). Searched 7 databases from 1990-2023. Estimated incidence rate differences under random-effects model.

What this study cannot tell us

RCT populations may be healthier than real-world older cannabis users. Most trials were relatively short-term. The wide confidence intervals for some outcomes reflect heterogeneity. CBD-only medicines were not separately analyzed in the abstract.

How to read the evidence

Large meta-analysis of 58 RCTs specifically focused on older adults, providing strong evidence for the safety profile in this population.

When this study was published

2024 meta-analysis

The bigger picture

The finding that cannabinoid medicines are generally safe but have predictable, dose-dependent side effects in older adults provides the evidence base for careful dose titration rather than avoidance. This aligns with the geriatric medicine principle of "start low, go slow."

Questions still open

What is the optimal starting dose for older adults? Do the balance and cognitive side effects translate to increased fall risk? How do cannabinoid side effects compare to those of medications they might replace (opioids, benzodiazepines)?

Common questions

Are cannabinoid medicines safe for older adults?

This meta-analysis of 58 trials found cannabinoid medicines are generally safe in adults 50+. Common side effects (dry mouth, dizziness, drowsiness) increase with dose, but serious adverse events and deaths were not significantly higher than placebo.

What side effects should older adults expect from cannabis medicines?

Dry mouth, dizziness/lightheadedness, balance problems, thinking difficulties, and drowsiness are the most common, all increasing with THC dose. These are important for fall prevention in older adults.

Read the original research

Adverse events caused by cannabinoids in middle aged and older adults for all indications: a meta-analysis of incidence rate difference.

Age and ageing, 53(11)

View on PubMed ↗Publisher’s paper ↗

Citation

Velayudhan, Latha; Pisani, Sara; Dugonjic, Marta; McGoohan, Katie; Bhattacharyya, Sagnik. (2024). Adverse events caused by cannabinoids in middle aged and older adults for all indications: a meta-analysis of incidence rate difference.. Age and ageing, 53(11). https://doi.org/10.1093/ageing/afae261