Baclofen Exposures Reported to US Poison Control Centers from 2000 – 2017

ABSTRACT

Background The number of baclofen prescriptions have increased steadily over the last decade, and published case reports have demonstrated the potential of this agent to cause significant CNS toxicity including prolonged coma mimicking brain death. To date, there is only limited data investigating baclofen exposures on a nationwide scale in the United States. This study aims to describe the incidence and characteristics of baclofen exposures reported to United States poison control centers (PCCs) from 2000 – 2017.

Methods National Poison Database System (NPDS) records were reviewed for all baclofen exposures from 2000 – 2017. Cases classified as “exposure” that included baclofen as a coded substance were included. For all exposures, demographic and clinical information was collected. For single-substance exposures to baclofen alone, specific information regarding treatments and clinical effects was collected.

Results 45,355 exposures to baclofen were reported to US PCCs from 2000 – 2017. The median patient age was 38 years, and 58.7% of exposures involved female patients. The average increase in reported exposures per year was 11.8%, primarily due to significant yearly increases in intentional-suspected suicide exposures. Seventy-nine percent of all exposures were managed in a healthcare facility, and 46.8% of these were managed in a critical care unit. In total, 20,609 exposures were to baclofen alone, and the primary clinical effects observed in these cases were drowsiness/lethargy (41.0% of exposures), confusion (13.65), bradycardia (11.4%), and coma (10.7%). The most commonly utilized therapies (and percentage of exposures in which they were utilized) were IV fluids (30.3%), oxygen (19.1%), intubation (14.1%), ventilation (13.0%), and benzodiazepines (10.5%).

Conclusions The rate of exposures to baclofen reported to US PCCs increased significantly during the study period, and this increase was largely driven by intentional-suspected suicide exposures. This may reflect an increased usage of the medication in patients at increased risk of self-harm. With nearly 4/5 of cases requiring care in a healthcare facility, and nearly 50% of those cases requiring admission into a critical care unit, this study suggests that baclofen exposures can cause significant toxicity and healthcare utilization.

Published in College of Pharmacy, Virtual Poster Session Spring 2020

Responses

  1. Do you think your findings support any recommendations in response to the increase in exposures? The increase in suicide attempts is quite dramatic.

    1. Thank you for your question! From Poison Center data alone it is hard to say what the primary driver of this concerning trend is, but it may reflect newly increased use of this drug in high-risk populations. Though our data could not tell us what the medication was being used for in these exposures, there is growing evidence that baclofen is being used off-label in alcohol use disorder; increased use may also be secondary to our response to the opioid epidemic as providers look for alternatives to opioids for chronic pain. People with alcohol use disorders as well as chronic pain may be a particularly at-risk group for psychological comorbidities and suicidality. I think our data has revealed that more research is needed into the use of this medication in these populations, particularly with regards to safety and whether there are certain populations more at risk of intentional overdose than others when using baclofen. Additionally, I believe our data serves as a warning to prescribers who may be considering using baclofen in their patients. Providers should consider whether these patients are at risk for self-harm based on their psychiatric history and comorbidities, as well as what other medications the patients are using that may increase or risk of overdose or enhance the toxicity of the drug.

  2. Nicely done, Brynne! It is concerning to see that nearly half of the cases end up being managed in the ICU. What was the most surprising finding of your results?

    1. Thank you Angie!

      I agree that the percentage requiring ICU admission is a concerning. In many cases, this could reflect the clinical severity of the overdose. However, it is generally the case that anyone presenting to emergency care with suspected suicidal intentions requires one-on-one monitoring (for psychiatric safety reasons), and in some settings (such as rural hospitals), the ICU may be the only place that is appropriately staffed for such monitoring. Unfortunately, our data cannot completely tell us whether medical or psychiatric reasons were the driving force for some admissions. However, when we look at the data for baclofen-only exposures (that is, cases where there were not concomitant intoxicants on board as well), intubation was required in 14.1% of cases, and coma was observed in about 10%. I think this still reflects that a large proportion of cases were quite serious, and this severity likely increased as more co-ingestants were introduced.

      For me, the most surprising data were:
      1) the sheer increase in intentional, suicidal exposures, in contrast to the unintentional exposures (e.g., children accidentally accessing grandma’s medication) remaining quite level despite a significant increase in baclofen prescribing over this time period (data not shown on poster). Usually when prescribing increases like this, those type of exposures increase as well, just because there is more of the product out in the world for kids to get into (kind of like how we are seeing increased exposures to Lysol and hand sanitizer at the Poison Center during the COVID outbreak right now). To sum, the isolated (and massive!) increase in suicidal exposures was quite surprising.
      2) I was also very surprised that beta-blockers were co-ingested in 13.2% of cases.

  3. Super interesting topic Brynne! It’s pretty alarming that there is a dramatic increase in intentional overdose with Baclofen over the years and such a large percentage requires ICU admission.

    1. Thanks for looking! I agree, these results are alarming. Check out my answer to Angie Vo’s question for my take on the ICU numbers, if you’re interested!

  4. Great study. It is very interesting to see your findings on this medication. Definitely something we can all be aware of as we go throughout our practice no matter what field we are in and do our part to lower these exposures.

  5. Brynne, great work sifting through all of these exposures!
    Any subgroup analyses planned for the future?

    1. Thank you!
      We are planning to take a look at therapeutic errors on their own, and we may be taking a look at the intentional exposures on their own as well.

  6. Hi Brynne,
    Nice job on your poster! Looks like much research went into it. Seems like Baclofen would be a medication
    that would really need to justified to prescribe based on your conclusions. Sure excited you’ll be finishing up soon! Congratulations:)

    1. Thanks you for looking! Yes I agree, I think it certainly should receive some scrutiny, especially if people are considering it a “safe” alternative to opioids. Thanks for the well wishes, too!

  7. It’s great to see your poster come together after being in the same project group over the past two years and seeing the development of the project. While disturbing, I think it’s a great find to identify these agents are becoming more prevalent in patients with intent to harm. Perhaps the results of this study may inform healthcare providers of the potential concerns of using baclofen in patients with unstable mental health disease.

  8. Brynne –
    What is your theory on why baclofen use has gone up so much? I have an idea but would love to see what you think –
    Very very important information – because people very casually use this drug.
    Dr G

  9. Really interesting. Nice job on this. Does the increase in overdoses parallel increase prescribing or has it outpaced the prescribing? Be interesting to know.

  10. Brynne, what is baclofen? 🙂 would have started out with stated what it is for and why there would be calls to the UPCC around this drug. Diana

  11. I retreat my last comment, or limit it to your abstract. Description is clear in your poster!

  12. Do the data reveal if there is any seasonal pattern in overdose?

  13. Brynne, sorry for not mentioning in my previous post, but this is a terrific study and analysis.

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