Q&A With A Cannabis Clinician: What Cancer Patients Should Know

For cancer patients wanting to use legal marijuana, it can be tough to find reliable information. So I asked Dr. Jordan Tishler, who runs medical offices in Cambridge and Brookline dedicated to prescribing cannabis, some basic questions about cannabis and the advice he offers his patients.

His comments have been lightly edited for clarity and length.

Is there enough research to conclude that medical cannabis can be helpful for cancer patients?

It’s inarguable that we could always use more data. Is there enough that we could make a reasonable decision now? The answer is clearly yes.

How could a cancer patient benefit from using cannabis?

Nausea and vomiting, appetite issues, fatigue, anxiety, insomnia -- those sorts of things that are associated either with cancer or chemotherapy, those things are very well treated with cannabis.

There has been a small amount of research suggesting that cannabis can also help treat cancer. What’s the state of that research? Is it believable?

We do not have enough information. We have some very beginning materials that are very encouraging and suggestive, but nowhere near the level we would expect if we started treating someone with any other medication.

Would you treat patients with cannabis instead of chemotherapy or other conventional treatments?

I’m very clear [with patients] that I’m not going to participate in this [care] if they are rejecting conventional treatment, but rather willing to participate in this as an addition to their treatment. Cancer patients who rely upon alternative medicines die more quickly than patients who use conventional therapy.

Do you see cannabis as an alternative to opioids?

Cannabis and opiates for moderate to severe pain really study out as being equally efficacious -- neither of them are super good. But the cannabis is much safer.

There’s clearly a place for opiates in our medical treatment regimen, but if you start with cannabis, maybe you don’t need to get to the opiates, or if you do you need to get opiates, we have really good data that you need a lot less. If you use cannabis and opiates together, you typically use only 20 percent of the amount of opiates you would have otherwise needed. With opiates, your risk goes up every time you increase [the] dose by a milligram. If you have someone who would need 100 mg of opiates, if you cut back to 20 mg, you’ve saved them 80 percent of the risk of the opiate. That’s huge.

"The way I look at this is the intoxication is a side effect and we need to manage the side effects, like with any medication."

What are the risks of using cannabis?

Every medicine has risks and side effects and we need to expect them. There’s no achievable lethal dose of cannabis, but that doesn’t mean cannabis can’t make you feel terrible if you overdose on it.

Intoxication or high for most of my patients is viewed as an unfavorable side effect. A lot of people approach me and say they want the kind of cannabis that doesn’t get you high. That doesn’t exist. The THC that’s causing the high is also what’s giving the benefit. The way I look at this is the intoxication is a side effect and we need to manage the side effects, like with any medication.

Is there a real difference between marijuana bought on the street and cannabis bought (at a higher price) from a licensed dispensary?

In a dispensary, all the cannabis is tested not only for potency, but for safety -- so not only heavy metals, but pesticides and mold are all tested for. We have seen cases of people who have smoked street weed getting fungal infections that can be lethal. I can think of two cases over four years -- one in Boston and one in San Francisco -- so we have to realize this is a very small number, but it’s something that we need to be aware of.

There are so many different cannabis products and options. How can people choose among them?

Some of them are just plain old BS. Bath bombs may be fun, but cannabis isn’t really contributing to that. The same can be said of topicals: creams, lotions and patches. Cannabis doesn’t penetrate the skin unless you do some pretty significant pharmaceutical manipulation, which most of these manufacturers aren’t doing at this point. And then also they cause side effects that lead me to wonder why we want to go there in the first place.

So the real choice is between inhaled and edible forms of cannabis?

I don’t recommend people smoke, because obviously exposure to smoke is not good for you, so that leaves vaporization. The advantages of inhalation are important. It’s really rapid onset. It has a modest duration of intoxication, meaning three to four hours. In many instances that’s an ideal length of time. Between the quick onset and your usable duration, inhalation turns out to be ideal for the significant majority of my patients.

And edibles?

Oral stuff is much more complicated. First of all, most people don’t need a heck of a lot of extra calories in their life. "Take two brownies and call me in the morning" is not good medicine.

[Oral also] has a much longer time to onset. Usually we think of it as about an hour, but it can be two to three hours before it kicks in, and it’s unpredictable when and why. The same person, same medicine -- one day it might be an hour, the next day it might be two hours. Why? I don’t know, but the point is, that makes it difficult to deal with.

Oral lasts longer. It has a duration that’s more like eight to 12 hours. In some instances, that’s good news. If someone has 24/7 debilitating pain, using oral to get better coverage is a great idea.

For most patients, their needs are more episodic, so the duration may be too long.

What about homemade products?

In the world of homemade, it’s very difficult to know what’s in that brownie. Even if you managed to do the math right, it’s squirrelly enough that it may not mix completely. This brownie on one side of the pan may be very stiff and the other very weak. If you have a brownie that’s an "I don’t know," I wouldn’t advise taking it, at least from a medical point of view.

You’ve been very careful to use the word "cannabis" instead of "marijuana." Why?

Marijuana is a slang term that has a racial stigma. It was used in early 20th century to stigmatize Mexicans and Mexican-Americans and to generate this idea that only seedy people use this stuff and "good" Americans wouldn’t touch this stuff. So, I try to avoid that kind of language.

Do you have a handful of tips to offer for cancer patients interested in considering cannabis?

  • It’s always important to start with a low dose and advance it only slowly.
  • It’s important keep in touch with your doctors, both your oncology team and your cannabis doctor.
  • It’s important to understand the difference between inhaled versus oral.
  • It’s also important to understand that the dispensaries are not a place to get information. The reality is there’s a lot of misinformation out there on the internet, which serves people poorly at this time. By and large, the people behind the counter at the dispensaries are simply parroting back a mixture of their own personal experience and that misinformation from the internet.


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Karen Weintraub Contributor, CommonHealth
Karen Weintraub spent 20 years in newsrooms before becoming a freelance writer. She's a contributor to WBUR's CommonHealth.



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