2023 Kill List: Medication-Induced Heat Intolerance
This piece was killed for a host of reasons, but the main one was we were both out of time for this to be timely (it was then September, summer heatwaves were over) and the research to solidify some claims in this piece was just not there yet.
The research is in development still, as reflected in emails to me by Professor Ollie Jay at the University of Sydney, when I asked him the following question:
In regards to how the body regulates heat exposure, how dangerous is it when a medication info packet indicates that a side effect is "sensitivity to heat" or some other phrase? What's the degree of risk to a person who is experiencing this side effect, but who lives in a hot climate and is used to heat, vs someone who is in a more temperate climate and experiences a heat wave?
My editor and I were stuck on how to quantify the severity of this risk -- all the public agencies in the US who might have answers for us had responded to me with no comment or similarly deflective responses. The question I kept coming back to was "if medical info is required to document risks and side effects of taking a drug, and this is a documented risk, why does it not arrive at a level of severity to be included in the info paperwork surrounding taking these medications?" I was unable to find, with the resources I had/under the timeline I had, any kind of rubric for why some side effects were mentioned in paperwork when meds are prescribed and why others are not.
This brought me to Prof. Jay and his colleague, Dr. Yorgi Mavrou. They replied to my questions (this was in mid-September):
Despite the strident statements that are made in various public health documents, the actual evidence supporting the true effects of different prescription medication on human thermoregulation is weak.
We are in the process of completing an exhaustive systematic review of all the evidence in the literature, which will demonstrate this (I am cc-ing the senior author on this review Dr Yorgi Mavros).
We hope to submit this review for peer-review in the next month.
In the meantime, we have established an experimental platform here at University of Sydney in the Heat and Health Research Incubator in collaboration with the School of Pharmacy to start systematically understanding these various effects on human thermoregulation. The first study is about to get underway pending final internal ethics approval.
and
As Ollie mentioned, the evidence that we have found on the impact on core temperature specifically is quite weak, particularly for antidepressant medications. However, there are a few caveats to this. Firstly, not all antidepressants have been tested, while many exposures in these trials only last a few hours where extreme heat events can last for days at a time. Furthermore, we are focussing on core temperature specifically, and while we do not see any evidence that our ability to maintain body temperature impacted, there could be other reasons as to why people feel worse in the heat. In clinical settings, it is also hard to separate the drug from the condition it is treating, so there may be other factors at play here that go beyond the biological effect of the medication.
While fascinating, this was frustrating, and I concluded that we had reached the end of this investigative piece for the time being.
My wonderful editor got me a kill fee and I decided to share the saga and the reported piece, as it stood in its last draft form, with you here.
(As an aside, I strongly recommend you read this incredible piece from The Washington Post this summer. Heavy and difficult though it is, it is some incredible coverage on an adjacent issue of mental health and heatwaves: https://www.washingtonpost.com/climate-environment/interactive/2023/schizophrenia-extreme-heat-health-risk/?itid=pr_enhanced-template_3)
Global temperatures keep passing previous high records this summer, as July saw the hottest month ever recorded on the planet, and August temperatures have been working hard to keep up with those record highs. Some municipalities with aging electric grids are struggling to keep up with power demands to keep everyone’s AC and fridges running in this heat, and are even urging citizens to reduce their usage as much as possible.
The struggle to adjust to the new normal of increased global temperatures is not limited to infrastructure: our bodies are not readily equipped to handle intense temperature fluctuations like the ones we’re seeing now. Our established medical practices, meanwhile, are based in a reality where normal temperatures of above freezing and below 86 F are necessary for our medicines to work properly.
As a result, it is becoming a matter of life or death that patients be adequately informed about what the heat might do to their bodies . Many commonly prescribed, life-saving medications—like heart medications, antidepressants, antipsychotics, and antihistamines—have serious potential side effects for people experiencing intense heat exposure.
What might normally be considered a mild, low-risk potential side effect of certain medications is quickly becoming dangerous for uninformed patients in a world where extreme global heatwaves are now common. Despite widespread acknowledgement that heat waves are dangerous, there’s little effort being made to inform the public about these compounded risks by public agencies, doctors, or big pharma.
Many common medications have a side effect called “medication-induced heat intolerance” which means that a patient may experience extreme physical reactions to heat exposure because their body is now less able to adequately regulate itself in heat. These reactions can range from mild (heat exhaustion or heat cramps) to severe (heat stroke), but all reactions in this range, if not taken seriously immediately, can accelerate quickly and cause major organ failure. If a patient is taking a new medication which has heat intolerance as a potential side effect, but they are not warned about this potential reaction, the patient might not take necessary precautions or react proactively to early symptoms of heat exhaustion. They might just assume that it’s hot and they are uncomfortable but it’s not a serious matter, which can be a deadly mistake to make.
Many of my fellow millennials (including myself) are on antidepressants to deal with things that might be considered the natural mental health ramifications of living with late stage capitalism and under climate collapse, but the joke is on us. Many, if not most, antidepressants are among the host of medications distributed without much discussion of their common side effect of heat intolerance.
Prescribers and pharmacies are obligated to provide patients with information about medications and common side effects. But the way this information is shared leaves something to be desired: it can be overwhelming and opaque (printouts from a pharmacy, received alongside medications, are not something most people spend time poring over), or superficial and inconsistent.
Anecdotally: I knew my antidepressant was one that affected my ability to tolerate heat because I tend to research my medications thoroughly. But I can’t recall being told directly that this was a side effect – and checking through the informational PDFs associated with this prescription on both MyChart and my pharmacy’s web portal log of my medications confirmed that a warning about this side effect was not listed in either place.
My pharmacist and doctor might be obligated to give me warnings about serious side effects and other risks associated with this medication, but for whatever reason the heat intolerance issue didn’t make the cut. (Virginia’s Board of Pharmacy media representative did not respond to multiple requests for comment on what, specifically, a pharmacist is obligated to tell me about such side effects.)
Few federal level agencies openly mention heat as a side effect of various classes of pharmaceuticals and the dangers of this combined with ongoing heat waves. I was surprised to find that, while the EPA had warnings about medication-induced heat intolerance which were pretty easily found on its website through related keyword searches, I could not find anything in recent featured media on this issue on the Federal Drug Administration, the Centers for Disease Control, or the Department of Health & Human Services websites, save for a lone 2017 flier from the FDA. Representatives from the FDA declined to comment for this piece about whether or not the agency had plans to address the issue in future messaging campaigns.
A few state-level health departments have taken some steps to raise awareness of this issue: the Ohio Department of Mental Health and Addiction Services released a brochure with warnings about medicine-induced heat intolerance risks in July this year, and Florida’s state health department released a similar brochure in 2015. This past summer, many state health departments released warning fact sheets or preparation guides about the ongoing heat waves, but medication-induced heat intolerance did not seem to be a priority for public awareness.
Many media and news outlets, however, have been diligent to make note of this risk to patients over the years: Consumer Reports discussed this in 2017, The Weather Channel had a piece about this in 2019, the Washington Post covered it in 2020, NPR reported on this last summer, Psychology Today covered it in 2021, AARP released a helpful guide about it this year, and KTRE Channel 9 in east Texas released some good coverage of the issue this summer, complete with a sober warning from a concerned local pharmacist.
Every time I mention this side effect to peers of mine who are on antidepressants and don’t work in the medical field, they are shocked and surprised to learn about this potential side effect. Pretty much all of them express that they were never warned about this risk and that “this explains so much!” (in the words of one friend) about how their bodies are reacting to the heat waves we’ve been living through the past few years.
Media coverage of this issue clearly does not begin to meet the need for public awareness of this issue. Me polling my friends on antidepressants is hardly representative of the population at large, but the lack of information about this on state health department websites and on prescription info sheets from my prescriber and pharmacy suggests to me that, at least here in Virginia where I live, patients are not being told much, if anything about heat interactions and their meds, and the news coverage of the issue isn’t doing much to counteract this information gap.
The risk of medication-induced heat intolerance has been widely accepted in the medical community as serious since at least the 1980s. It is therefore baffling that public health departments, and state and federal regulatory organizations are not pushing prescribers to consistently and clearly warn patients of this risk when they begin using such medications. As global temps rise, this lack of awareness will become more and more deadly to the lives of uninformed patients.
NOTE: if you read this far, thanks. If you're expecting more Quiverfull/homeschool reform content, hang tight. More to come.