Sativex spray for MS spasticity did not impair driving and most patients reported driving improvement | Research

The takeaway

A review of driving studies and real-world registries found no increase in motor vehicle accidents from THC:CBD oromucosal spray (Sativex), with most MS patients reporting improved driving ability after starting treatment.

Read this if you have MS, use or are considering Sativex, and are concerned about whether it will affect your ability to drive.

No increase in motor vehicle accidents; most patients reported improved driving

What the researchers found

Researchers reviewed all available evidence on whether Sativex, a THC:CBD mouth spray prescribed for MS-related spasticity, affects driving ability. The evidence was reassuring.

Driving studies and real-world registries showed no increase in motor vehicle accidents associated with Sativex use. Most patients actually reported improved driving ability after starting the medication, likely because reduced spasticity and potentially better cognitive function outweighed any mild impairment from the THC component.

An important pharmacological distinction was noted: blood THC levels from Sativex are significantly lower than levels associated with recreational herbal cannabis use. The controlled, metered-dose delivery of the spray produces more stable and modest THC exposure compared to smoking or consuming cannabis.

However, the review cautioned that THC blood measurements after Sativex could exceed legal driving thresholds in some countries, recommending that patients carry a medical certificate and know their country's specific regulations.

Why it matters

For MS patients, losing the ability to drive can mean losing independence. Many patients fear that a THC-containing medication will prevent them from driving. This review provides evidence that at therapeutic doses, Sativex does not impair driving and may actually improve it by reducing the spasticity that was affecting driving performance.

The numbers in context

No increase in motor vehicle accidents associated with Sativex use. Majority of patients reported improved driving ability. THC blood levels from Sativex significantly lower than recreational cannabis. Blood THC may still exceed legal thresholds in some countries.

How the study worked

Systematic PubMed search from 2000 to 2017 for articles on THC:CBD oromucosal spray and driving performance, supplemented with relevant references and known articles. Evidence from driving studies and real-world patient registries was synthesized.

What this study cannot tell us

The review relied on limited driving study data and real-world registries rather than large randomized trials specifically designed to assess driving. Patient self-report of improved driving may be biased. The legal implications of blood THC levels vary by jurisdiction and were not comprehensively mapped. Long-term effects on driving were not assessed.

How to read the evidence

This is a review of driving studies and registry data, providing moderate evidence of driving safety with important caveats about legal THC thresholds.

When this study was published

Published in 2018 with evidence through mid-2017. Driving regulations for medical cannabis continue to evolve.

The bigger picture

This review highlights the important distinction between medical cannabinoid use at controlled doses and recreational cannabis use for driving safety. The finding that the therapeutic benefit (reduced spasticity) appears to outweigh any cognitive impairment from modest THC exposure supports the concept that the net effect of a medication on driving depends on both its direct effects and the condition it treats.

Questions still open

Should drug-driving laws have medical exemptions for patients on prescribed cannabinoid medications? How do blood THC levels from Sativex compare across different national legal thresholds? Would objective driving assessments confirm the subjective improvement reported by patients?

Common questions

Can I drive while using Sativex?

This review found no evidence that Sativex impairs driving in MS patients, and most patients reported improved driving ability. However, blood THC levels may exceed legal driving limits in some countries, so you should check your local regulations and consider carrying a medical certificate.

Is Sativex different from smoking cannabis for driving?

Yes. Blood THC levels from Sativex are significantly lower than those from recreational cannabis use. The controlled, metered spray delivers modest, stable THC levels compared to the high peaks from smoking.

Read the original research

The influence of THC:CBD oromucosal spray on driving ability in patients with multiple sclerosis-related spasticity.

Brain and behavior, 8(5), e00962

View on PubMed ↗Publisher’s paper ↗

Citation

Celius, Elisabeth G; Vila, Carlos. (2018). The influence of THC:CBD oromucosal spray on driving ability in patients with multiple sclerosis-related spasticity.. Brain and behavior, 8(5), e00962. https://doi.org/10.1002/brb3.962