Dec 08 2017 . 11 min read

Elevating the conversation with robert l. Cook, md, mph, professor in epidemiology

Elevating the conversation with robert l. Cook, md, mph, professor in epidemiology

Director of the Southern HIV and Alcohol Research Consortium (SHARC) and Chair of the Florida Consortium for HIV/AIDS Research (FCHAR)

Director of the Southern HIV and Alcohol Research Consortium (SHARC) and Chair of the Florida Consortium for HIV/AIDS Research (FCHAR)

University of Florida Health’s Dr. Robert Cook is lead investigator of a study starting in January that will look at the health effects of cannabis on people with HIV as well as its potential as an alternative to addictive opioids. Awarded a $3.2 million R01 grant from the National Institute on Drug Abuse (NIDA), Dr. Cook and his team will conduct a study of 400 persons living with HIV infection to identify relationships between marijuana consumption and control of HIV symptoms, HIV viral suppression, markers of chronic inflammation, and cognitive or behavioral aspects of health.

Florida has the third-highest number of residents living with HIV infection in the U.S., according to a 2015 study conducted by the Center for Disease Control and Prevention. Was that a factor in why you developed this study?

Fifty percent of people with HIV in Florida are now 50 years old or more. So, we have a lot of older people who currently use marijuana or who are thinking about it. And we don’t have a lot of information on what happens to people over age 50.

What was the impetus for you to study the effects of cannabis on HIV?

As a clinician, I have seen a lot of patients who seem interested in trying medical marijuana for a variety of conditions. I was looking for some data to support which kinds of marijuana might be more beneficial than others and I couldn’t find any evidence so I decided we really needed to do some type of study.

Had you researched cannabis before you decided to do this study?

In the last couple of years, we have been doing some research looking at marijuana and its effects on cognitive function. We have also been looking at marijuana use in HIV viral suppression and we have been looking at a few other things but most of this is limited because all we know about people is: Do you use any marijuana; and if so, how often? So, we can compare people who report daily use vs. non-daily use. We were frustrated by how limited information about how people use marijuana was in the current research. For our study we are going to try to ask a lot more questions about what kind they use; do they get it from a dispensary or not; do they ingest it or smoke it or vape it? We are going to do a urine toxicology to try and figure out if what they use has any of the cannabinoids in it or if it’s only THC. I think there’s a lot of medical interest around the CBD part. It does seem like what’s available to purchase is mostly THC products and the CBD stuff costs more. I would like to be able to tell patients if this is worth it. We need to have data to show if you do have a CBD product that it is better for pain and things like that. Those are the types of questions that I think we need more data on but have been hard to study because marijuana is illegal at the federal level. It’s very hard for researchers to directly study it. One of the biggest limitations of the research we are going to do is that it is going to be reported by the participants themselves. Even though we are going to do this urine screen to see whether there’s THC or not, we still aren’t directly controlling what people use or don’t use. It’s all based on their reporting.

As you begin the study, what is your hypothesis for medicinal cannabis and HIV?

I do believe that people who are getting effective relief from pain, for example, will be using it slightly differently than those who don’t get effective relief from pain. I suspect the CBD part is important, but I don’t have a lot of data to prove it. And I am interested in comparing some of the side effects of people are who are using products that are either long-lasting or that they use several times a day compared to people who use marijuana intermittently. Because even with that I wonder as a physician should we be encouraging people to just dose it all day long versus use as needed. There is an endocannabinoid system in our bodies that’s natural and it may react differently when people are constantly being exposed versus intermittent and I am not sure yet which is better.

Many HIV patients take cannabis to help with sleep, pain and stress, do you believe any other useful information will come out of this study such as aiding HIV’s viral suppression?

It’s very challenging to really prove whether it is helping or not in terms of things like anxiety and stress because we are enrolling people in our study who are already using it for anxiety and stress because you really don’t know what their level would be if they weren’t using it. People may perceive that’s helping but we really don’t know. I hope I get some people in the study who haven’t used marijuana before and they begin to use, because it’s now legal to prescribe it for people with HIV in Florida, so that will be interesting to see what happens to people when they haven’t used it before and now they start. We are also especially interested in inflammatory markers. HIV virus, if it’s unsuppressed, does cause chronic inflammation in the body and thatis usually associated with more rapid aging, more rapid progression of heart disease, and probably feeling fatigued and tired. If marijuana could suppress some of that chronic inflammation or at least some parts of marijuana, it really could help people with a chronic virus feel better. We do suspect that many people truly do feel better with it and I suspect it’s because of its relationship to inflammation. But most of the data we have so far is short-term studies, which are helpful, but we will be looking at a longer view, over several years and that will be something different about our study over previous studies.

How many study participants do you need?

We want 400 participants who ultimately will use marijuana, we will have probably at least 100 who don’t use marijuana as a comparison group.

What do you see as your biggest challenge regarding this study?

Science is an animal project, you can control everything except for the marijuana and learn a lot. But in real life our participants, in addition to having different marijuana patterns, also do have different patterns of other substance use, different medical comorbidities, and different experiences of stress and abuses in their lives. It can be hard to tease out an effect with all this variation but at the same time that’s the real world. People living with HIV in Florida do have many medical conditions like high blood pressure, diabetes, depression and so we want to know if it’s safe to use in these types of people with lots of health issues.

UF Health researchers applied for the NIDA grant twice before receiving it. How many years have you been trying to get this study in place?

At least two years. This is kind of a common story with National Institutes of Health-funded research. Usually you have to be in the top ten percent of grants to get it and those often take several tries where you get feedback from other scientists who make suggestions on how to improve the science and I tried to be responsive to their suggestions. For example, they did think we should focus a little bit more on pain and pain medication so we tried to adapt the study to that.

Do you think the reason you received the grant has to do with the nation’s opioid problem and cannabis’ potential to be an alternative?

You would have to ask NIH, but I do think our grant was funded in part because there are so few studies trying to gain scientific evidence on marijuana and any type of chronic health issue. HIV is one, but they might be interested in other types of conditions people might use it for. We have very little information and so there was a perception in the past that NIH was more interested in marijuana as a drug of abuse and not so much on its health effects. But I do think that attitude has shifted a lot in the last ten years where NIH is open to both and looking at it as a drug that could be beneficial while also it could still have harms associated with it.

With the $3.2 million grant from the National Institute on Drug Abuse, you are in a very elite group, researchers who have been given a federal grant to study cannabis, did you think you would get federal funding?

That’s what I have been trained to do for my academic career. They train us to write grants and as you gain more experience as a scientist you learn to write better grants and you get feedback that helps you to be a better scientist. I was optimistic that we had a good chance to get funded, otherwise, I don’t think we would try but it is a competitive process and certainly takes a team of scientists, and I have a great team with a lot of different areas of expertise and I think that helps. There is just a need for research.

I do hope over the next several years the information that we get will be helpful. It’s important to me that the data we collect ultimately will help to guide patients who might benefit, to guide people who might be vulnerable to harm, to guide providers, at least in Florida, who are specifically recommending doses and types and writing prescriptions which is different than what I think is happening in many other states in which people can get a license and the clinical recommendations are made by the people working at the dispensaries.

I should note that the people working at the dispensaries often seem to have an incredible abundance of knowledge about the medical effects. So how do we translate what they seem to know to data that’s more typically required in order to practice medicine in the U.S.? We don’t just want anecdotal reports or personal experience, we want harder data. It does seem like people know a lot of information out there and I want to try and translate some of what they know into more typical health data. Our research can influence practice guidelines and things as simple as do sativa products truly cause people to feel more alert and creative? Do indica products cause people to really be more laid back and sedate? And is that the same in people who are older than 50? Those are the type of things I would want, as a provider, to know and make suggestions as to which product a patient should try.

What are some potential negatives that could result from the study?

We have to be really careful about confidentially, when you do this type of research we have staff that we train, but staff can make mistakes. We have to do our best to ensure that people aren’t outed as being HIV positive or that people aren’t outed because they are marijuana users. There is a lot of need for researchers to make it safe for people to participate.

What about cannabis being federally illegal?

People are worried at the University that we could lose federal funding because it is involved in research that is federally illegal. When the political administration is stating pretty clearly they aren’t going to tolerate a lot of marijuana activity and that’s the public stance, we need to be cautious. As a researcher I am not applying to have marijuana onsite. We do have the potential to work with the dispensaries themselves and let them dispense the products which they can do legally and collaborate with them as scientists to try and do some clinical studies. That’s something I am interested in, in the next year or two, to really figure out a way where we can try to randomly assign people who are willing to participate in a different study with product A vs. product B, or product A that’s consumed orally vs. inhaled and see if we can get some clinical evidence both in terms of people’s perceived symptoms, which is important, but also any biological measures like inflammatory markers. Ultimately, I do hope we generate some data that can be helpful for consumers and providers.