Experts Explain: Not what the doctor ordered. Why smoking medical cannabis is harmful

If you’re a medical cannabis patient, or looking to become one, you may be wondering: ‘is it okay to smoke my prescription cannabis?’ - and the short answer is an unequivocal no. 

While smoking cannabis has been a common route of administration for millennia, UK law forbids this - simply put, because cannabis-based treatments are prescribed to improve health and smoking undermines this, as it is a well-known hazard to health. 

When medical cannabis is prescribed in the UK, it is done so with strict instructions to be administered using a vaporiser. In this blog we’ll hear from Dr Alexander Van Heerden, one of Releaf’s prescribing medical cannabis doctors, who has eight years of experience in emergency and cannabis-based medicine on how smoking prescribed medicines effectively defeats their purpose: which is to improve an individuals' health, wellbeing, and quality of life. 

In this insightful interview, Dr Van Heerden gives a comprehensive overview of the smoking vs vaping cannabis debate, covering the health implications, legal considerations, and medical inefficiency of smoking cannabis, while exploring the benefits of vaping, and his top tips for those transitioning. 

Read what he had to say here:

What is the difference between smoking and vaping cannabis? 

“Categorically, smoking and vaping are different. Firstly, from a health perspective we’ve known for a long, long time that smoking is bad for you because it causes so many issues with health, and vaping has been a new solution to that problem.

But realistically, there are a number of advantages to vaping cannabis as opposed to smoking it:

Advantage one: lower risk

The first advantage is what we call the thermal component, i.e. the temperature. So, the injury to our lungs from smoking is often caused by the high temperatures of the products that go into your lungs - that's what we call thermal injury. Because vaping is typically at lower temperatures, it removes that risk. But, there is another side to that as well….

Advantage two: fewer byproducts

Combustion, or smoking, also causes harmful byproducts to be produced, like carbon monoxide and other carcinogens, and that's another reason why smoking is more dangerous than vaping, because at those lower temperatures, it's vaporised, it's not combusted, and it removes that risk. There's also fewer toxins produced.  I’ve already mentioned carbon monoxide, but there are other components we call volatile organic compounds, which are really risky for the lungs. 

There was actually a study done in 2016 showing that vaping produces a significantly lower level of those organic compounds. So we know it's safer from that perspective, but there's another side to it - a physical one: namely, irritation. 

Combustion makes particulates. If you've ever started a fire, you'll see sort of smoke come out in that smoke is tiny little bits of grit, or what we call particulates. When inhaled, that irritates the throat mostly, but also the lungs, which can produce excess mucus. When cannabis is vaporised, it's not combusted and so, it removes that risk.

Advantage three: accurate dosing 

The next advantage, really, is dosing. Because vaporisers have much better control over temperature and dosing, it's much easier to use for medicinal use, because we know exactly how much you're receiving from that vape. So it's just more precise in that respect.

Advantage four: legal compliance

Then, of course, there is the legal aspect. For good reason, smoking cannabis, even medical cannabis, is illegal - and a lot of our patients don't realise that when they first join Releaf. 

They often think because it's medical cannabis smoking it is fine, but, it’s not - it's still illegal to smoke medical cannabis. To me, it makes complete sense that the UK government won’t permit a method of administering medication that is counterproductive to its use.”

And, how do you address this during consultations with medical cannabis patients?

“Usually, I explain what I’ve just explained to you - the benefits from moving from smoking to vaping are so diverse so it depends on the person, but I’ll always go through the impact it can have on health. I also like to pass on feedback other patients have told me, that they feel so much better after they’ve moved onto vaping, and those improvements are usually felt within the first or second week. 

The common things that patients tell me in the follow-ups are that their gym capacity, or exercise capacity, has gone up so much. A few months down the line, they'll often tell me, “Doctor, I've noticed that I'm not getting as sick as I used to, like, you know, I used to get sore throats all the time. I'm not getting that anymore!” They'll tell me that their lungs feel lighter and cleaner, and these are all positive effects.

When I tell my patients about these positive effects that others have commented on, they tend to get quite excited about it, because everyone knows smoking is bad for you, but it is really hard sometimes to quit. I mean, it's one of the hardest things to do, but vaping makes it a lot easier, because you get all these benefits.”

You said vaping allows for more precise dosing. Does that mean patients can actually use less product and get the same effects when they switch to vaping? 

“Definitely.

In the combustion process, a lot of the medicinal components of cannabis are destroyed, but vaping allows for more precise dosing to get the desired effect. It's another thing people commonly mention in follow-ups, that they don’t need as much as they thought - especially those who have been self-medicating by smoking street cannabis - they often suddenly find they don't need as much. Of course, that’s also to do with the differences in prescribed cannabis and street cannabis, as well as delivery method. 

When it comes to terpenes, it’s quite a complex science. Different terpenes are amplified at different temperatures, and that's another advantage for vaporisers - they often have temperature control settings.  

The vaporisers we sell in the Releaf store are optimised for medical use, and on some of the devices patients can alter the temperature settings slightly to adjust for different cultivars, or different terpene profiles if need be. We do talk patients through this if needed, but generally the temperatures don’t differ too much, so a lot of patients don’t have to adjust their device if they switch to a different cultivar.”

What would your stance be if a patient told you they’d been smoking their medication as opposed to vaping it?

“Firstly, I think it's important to say that we have our patient’s health as a primary concern. We will encourage them, on that basis, to move to vaping as much as we can, because ultimately, we are here for their long term health, and they are definitely way better off vaping it than smoking.

We will always remind them as well that it is still illegal to smoke cannabis, be it medical cannabis or street cannabis. As I said earlier, some patients don't realise that, so we'll remind them of this, and tell them they’re invalidating their prescription status by administering their medication in a way that is illegal. 

However, if they refuse to take this guidance seriously, and continually ignore prescribing instructions, we, as doctors, have a duty of care to escalate it.

That being said, I have yet to meet anyone who has gone back to smoking once they've transitioned into vaping, because it is that much better for all the reasons we’ve already touched on.”

Vaping itself is a relatively new phenomenon, so in terms of long term health risks – they aren’t entirely clear yet. How does this factor in?

“Correct, we’re not sure of the long term effects yet, but we are absolutely sure that it's going to be significantly healthier than smoking. The main problems with smoking cannabis really, from a health perspective, is the thermal injury and the toxins that were produced during the combustion process. I have absolutely no doubt that everyone's health will be improved by moving from smoking to vaping.

In general terms, not knowing the long term risks of new medicines – or in this case administration methods – is not new – it’s par for the course so to speak.

Medicine is a unique industry in that way, new products and processes are continually being developed and established, and getting new treatments for diseases and health conditions does take time, and establishing the safety of these – both long term and short term – again, takes time. 

That being said, I think we're at a stage in medicine now, where we are also really good at predicting potential problems, we have that power and that knowledge. With vaping, I suspect that the risks will be low.”

Releaf are introducing vape cartridges that contain cannabis oil into their formulary. Are there different risks associated with these products, than there are with dry herb vaporisers? 

“From our perspective, there aren’t any further risks associated with the vape oils or cartridges than there are with vaping flower, and personally, I think these make a fantastic addition to our formulary, and what we’re able to offer Releaf patients.

In terms of vaping oil, there was a concern at one stage about lung injuries, its medical name is EVALI –  but that’s an e-cigarette associated lung injury. We quickly figured out that actually, that was due to a particular contamination in the vaping cartridges found on the black market, and it's caused by a compound called Vitamin E acetate. 

This compound is very much found on the black market equivalents of what we prescribe to patients, and in medical grade devices and the SOMAÍ cartridges we stock, this isn’t present. The media reports you hear of about ‘popcorn lung’ are not relevant in this circumstance, and overall, there are very few, and low, risks associated with them.” 

So, there are two options when it comes to vaping for patients, vaping cannabis flower and vaping cannabis oil. But, are there circumstances where vaping isn’t a suitable administration method at all? 

“Yes, and that’s a really good question. There are patients with COPD, asthma, emphysema, or chronic lung irritation, and we take different approaches to treatment for those patients on a case-by-case basis.

For someone with established COPD, if they have stopped smoking altogether, they are likely to be better off from a health perspective, using edibles/pastilles or taking cannabis oil orally to control their symptoms. However, if they have COPD and they're still smoking tobacco, they may be better off moving on to a vape if they need that rapid delivery – but oil taken orally (under the tongue) is likely to be the best approach all together. 

Meanwhile, those with really brittle asthma can find that vapes exacerbate or spark their asthma quite significantly, depending on their lung capacity, so in those circumstances an oral route as opposed to an inhaled route would be favoured. Obviously, everyone’s quite different, so we look at every patient quite individually.

From a lifestyle perspective - some people find the oils easier to take because they don't have any odour that is typically associated with vaping – although, vaping is still far less ‘smelly’ so to speak than smoking is. Oil is also more subtle to take, so some patients who need to use their medication in social situations or at work, often prefer to have an edible or oral option that would help to control their symptoms in a more discreet way.”

And finally, what advice would you give to medical cannabis patients when transitioning from smoking to inhaling vaporised cannabinoids?

“There are so many different elements to think about, so I cater my advice to each patient. 

Some individuals who have been self-medicating by smoking cannabis prior to coming to Releaf express some concern about changes to the routine, or ‘ritual’ so to speak, that they’ve been used to - but I think that is quite easily replaced with vaping. 

There's still the preparation side of things, filling the flower-sticks or vape canister, the only thing that’s different is vaping sessions are typically over within a matter of minutes, as opposed to an extended period of time. But, as I said before, the effects are felt much sooner with vaping. 

Some patients transition over a period of time, and those who previously mixed cannabis with tobacco, now just tend to have a cigarette after their vape - often, slowly cutting down on these too. 

For the most part, patients who move on to vaping completely don’t tend to have a problem, and instead, reap the benefits. For those who are struggling to completely transition, I’d recommend looking into cognitive behavioural therapy (CBT) or even hypnotherapy, as they can be very useful in this area, and in smoking cessation all together.”

Final thoughts

As Dr Van Heerden outlines, switching from smoking to vaping cannabis isn’t just a compliance issue - it’s a chance to truly benefit from medical cannabis. If you are taking the proactive steps to help your health by seeking out these treatments, it's worth asking why would you want to sabotage not only your results, but also your overall health for a matter of familiarity. 

If you’re ready to see the difference medical cannabis may be able to make, leave smoking behind. Your lungs, and your future, will thank you.