Michael Weiner, MD, MPH, Research Scientist at Regenstrief Institute and U.S. Department of Veterans Affairs and Professor of Medicine at Indiana University School of Medicine talks about how mixing medications can be dangerous.
Interview conducted by Ivanhoe Broadcast News in 2024.
What is a drug-to-drug interaction?
Weiner: A drug- drug interaction happens when two or more drugs interact so that the effectiveness or toxicity of at least one of the drugs is changed. These are common events.
It doesn’t necessarily always impact the patient, but it does impact the effectiveness of the drug. Could it go either way?
Weiner: Yes. It could enhance or change the effectiveness of the drug. It may lower the effectiveness of the drug, and it may create toxicities. Any of these effects could have important outcomes for the patient.
What are the effects for the patient?
Weiner: These drug interactions can have a wide range of effects that can range from mild to deadly. Examples may include bleeding, muscle pain, or even changes to heart rhythm, which can be serious.
How common is a drug-to-drug interaction?
Weiner: Drug-drug interactions are extremely common in the U.S. In a year, about a quarter of a million hospitalizations occur as a result of these interactions at a cost of more than $1 billion. So it’s a serious problem.
Maybe not something we hear about a lot, but it’s happening a lot.
Weiner: Absolutely.
How do doctors and nurses process the information of what you’re currently taking to decide if this new medication is okay?
Weiner: Well, most hospital settings, as well as practices, now use electronic health record systems. These systems typically have alerting systems to inform the prescriber about one of these potential problems. The systems have to stay up to date with the drugs and the evidence about them in order to be effective. In addition, pharmacists are an essential resource for this type of information.
Are they updated pretty frequently, and do they get good information when they’re across different medical practices?
Weiner: I like to think so. The systems vary and an institution may vary in how it actually updates its own information systems. But I think, by and large, prescribers are trying to get the most accurate up-to-date information that they possibly can.
If a patient is seeing different doctors for different things, does that increase their chance of a drug interaction?
Weiner: If the coordination of care is not done well, a drug-drug interaction could be overlooked, and with more and more doctors that a patient is seeing, the coordination becomes more and more difficult. In addition, we need to know all of the drugs that a patient takes if we are hoping to find all of the potential interactions. So that set of information is critical and it’s hard to get.
When you go to the doctor and they say, “What medications are you on?,” you may just think of one thing and can’t remember the other, and that’s critical.
Weiner: Absolutely. I recommend that patients actually bring not only a list but the bottles, the tubes, the other containers that these medications are in. The next best thing is the list. The next best thing is if the patient actually knows what they take, although we always want them to know what they take so that they could tell someone else or become more knowledgeable about these drugs.
The dosage and how long you’ve been taking it, are those things important as well?
Weiner: Very important including whether any reactions have occurred to any of those medications or other medications that the patient may have taken previously.
Are there certain medications that seem to interact negatively more than others? Are there some that just don’t work well together?
Weiner: Well, several commonly prescribed types of medications are especially likely to lead to interactions. These include antibiotics, blood thinners, blood pressure medications, cholesterol medications, and drugs used to treat mental illness. We especially have to watch out for those.
I’m going to throw out a hypothetical situation – a patient is in visiting their doctor and it’s determined they need a medication for what they’re seeing their doctor for that day. The doctor, whether within their own knowledge or they put it into the system and they find out what works and what doesn’t with something they’re currently taking. How do they navigate that? What are the options and how do they navigate the risk and benefits of that?
Weiner: Good question. The clinician, I would say has three steps. First, they have to identify that the problem is there or that there may be a potential interaction. Second, they really have to assess the risk of that problem. What’s the magnitude of the problem? How likely is it? And so on. Third, they need to make a decision ideally in collaboration with this patient and sometimes with other colleagues, whether it’s pharmacists or others. The decision might be to change the drug, it might be to change the dose of a drug, it might be to stop the drug, and it might be to accept the risk. In some cases, there are other options and pathways, but those are all very important to consider.
You say most of these interactions are preventable. Tell me about your study and what you found when it comes to addressing these possible interactions.
Weiner: This study was led by Doctor Alissa Russ-Jara and was sponsored by the US Department of Veterans Affairs. It was the first study that used a technique called cognitive task analysis to look at real-world decision making about drug-drug interactions. Clinicians submitted incident reports as part of this study in their own practices about potential serious drug interactions, and we then interviewed those prescribers to understand their exact decision making process at every step along the way. We identified 19 information cues that the clinicians use to make decisions and assess the problem. And these included things like whether the electronic health record system did alert them. How likely was the problem to occur? What was the magnitude of risk? Did the patient really need the drug and how important for the treatment was that drug for that patient? And in addition, did the patient have a history of this type of drug drug interaction?
What about for the clinicians that were involved? Was there anything that surprised them with how they’re doing things?
Weiner: What sometimes surprises clinicians is that they have too much information and they’re trying to wade through it and find the most important parts of it that are really going to be the key deciding factors for them. So this is a great challenge. Fortunately, technologies can help in some situations, and some of the electronic health record systems are very competent at doing that.
What did you find from the study? What did you find as the best solution to prevent these or what do you think could or should be done to prevent these? What was the main takeaway?
Weiner: I would say two main points came from this work. The first is that prescribers need greater awareness and knowledge about these potential drug interactions. The second is that we need more systematic approaches to actually addressing and resolving the problems. This includes helping prescribers know what the alternatives are, and what the best options are, for resolving a specific drug interaction that’s at hand.
This is for the patient. If someone starts taking a new medication, they’re prescribed by their doctor and they go home, maybe the doctors discuss some risks, but they go home, they start taking it in the days or maybe weeks to follow. Are there things that they can look for that would be a signal that something’s not going right about this new medication, in general, or possibly an interaction with another medication?
Weiner: Absolutely. If a patient’s taking a new drug or has a dose of a drug changed, and they start feeling ill in any way, they should alert their health care provider, whether it’s a pharmacist, a physician, a nurse practitioner or someone else. The range of possible symptoms is large. So patients may get nausea, they may get pain, they may get headaches, they may get abdominal symptoms. So there isn’t any limitation really on the nature of the symptom, but if they have symptoms, they should report them immediately.
Are there things the patients can do on their end to prevent these interactions?
Weiner: I think of three things. So I call these know, bring, ask. Know the drugs you’re taking and why you’re taking them. That’s first, second, bring the drugs to your doctor’s visits, and third, ask your healthcare professionals if any of these drugs will interact with each other. If you cover those three areas, you’ll be in pretty good shape.
Going back to the study, what was your main takeaway or was there anything that surprised you when you were reading the results and getting the results?
Weiner: I think clinical decision making is very complex, and even the most senior, most expert clinicians don’t always have full insight into their own decision making process. So the way that we conducted this study and taking that process apart actually helped us understand it in a new way. And that was one of the key benefits of the study we did.
What are you hoping to achieve with this? What do you want to bring into other medical practices and really get out to doctors? What are you hoping they’ll take away from this?
Weiner: We would love to see more systematic decision making, better information systems and tools that will help us assess risk and make decisions more efficiently and more effectively.
How easy is it for a doctor to tell a patient that they can’t use a particular drug, or find a new one because they need this medication too?
Weiner: Although some decisions are easy, it’s often not very straightforward because there are so many factors involved in the decision including how quickly the patient needs the drug and what the potential side effects actually may be. So the process involves accessing a lot of medical knowledge about the drugs and also accessing the patient’s own medical history. And both of these sources of information are large potentially. So there’s a lot to sort through.
Is there anything else you would like to add?
Weiner: I have one last message. If someone asks you why you’re taking a drug, and you say, because my doctor told me to take it, I would say you have some more homework to do.
With your study, how long did it take from start to finish? When did you start working on this?
Weiner: Well, from beginning to end, it’s many years because the study has to be developed. That can take a year. Then the study has to be funded. That could take one year, could take two years or more. And then the study itself- this type of study will often take about four years. Then we prepare reports, articles, manuscripts, and that process can take a year. So it’s a long process.
How many clinicians were involved?
Weiner: We had 20 different cases that we analyzed. It included pharmacists and physicians mostly. We had a nurse practitioner as one of our participants. And then the study team has about 6-10 people of different roles, analysts, investigators, methodological experts in certain areas, clinicians. So it’s a diverse group.
END OF INTERVIEW
This information is intended for additional research purposes only. It is not to be used as a prescription or advice from Ivanhoe Broadcast News, Inc. or any medical professional interviewed. Ivanhoe Broadcast News, Inc. assumes no responsibility for the depth or accuracy of physician statements. Procedures or medicines apply to different people and medical factors; always consult your physician on medical matters.
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Regenstrief Institute
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