Do beta blockers nullify adrenaline rush in an actual emergency?
February 9, 2025 2:41 AM Subscribe
Medical/science MeFites: as I understand it, beta blockers block adrenaline from affecting heart rate, among other things. Is this a complete block, or is it more like raising the threshold at which adrenaline takes effect? What happens in a classical adrenaline rush situation like a house fire?
Not a medical person, but I do know of two cases where beta blockers can have adverse emergency effects.
The first one is that they reduce the effectiveness of EpiPens or other anti-allergy meds (my allergist always asks every patient before every allergy shot if they are on beta blockers as a consequence; no idea if they are overly paranoid though).
The other is that they definitely reduce exercise capacity. A reduction, not a deletion, but you still can’t run away as fast.
posted by nat at 4:09 AM on February 9 [1 favorite]
The first one is that they reduce the effectiveness of EpiPens or other anti-allergy meds (my allergist always asks every patient before every allergy shot if they are on beta blockers as a consequence; no idea if they are overly paranoid though).
The other is that they definitely reduce exercise capacity. A reduction, not a deletion, but you still can’t run away as fast.
posted by nat at 4:09 AM on February 9 [1 favorite]
Adding anecdata to nat’s comment: when I started on a beta blocker, it dropped my base heart rate about 8-10 bpm, and my peak by about 25 bpm. My top running speed didn’t decrease, though. (It’s been several years, and the effects on my heart rate still persist.)
posted by DrGail at 6:18 AM on February 9 [1 favorite]
posted by DrGail at 6:18 AM on February 9 [1 favorite]
I wonder if my own experience (definitely reduced my speed and distance hiking) was due to the fact that I was on beta blockers because of a mistaken diagnosis. When I went back off of them my capacity eventually returned to normal.
posted by nat at 7:34 AM on February 9 [1 favorite]
posted by nat at 7:34 AM on February 9 [1 favorite]
As an aside, I recommend reading all of the side effects listed for the drug from a reputable source before you start taking them. Same for all drugs actually.
I experienced a couple of the rarer effects. The doctors I've worked with often didn't know about these, even if they were prescribing them and they're very common.
If you know what to look for and encounter any issues, at least you can make an informed decision as to whether to continue taking the medication.
posted by DrumsIntheDeep at 7:42 AM on February 9 [1 favorite]
I experienced a couple of the rarer effects. The doctors I've worked with often didn't know about these, even if they were prescribing them and they're very common.
If you know what to look for and encounter any issues, at least you can make an informed decision as to whether to continue taking the medication.
posted by DrumsIntheDeep at 7:42 AM on February 9 [1 favorite]
I take beta blockers for tachycardia (SVTs). Initially, I stopped taking them because they're a bit sedating, but now I take a low dose at bedtime, and I seldom have tachycardia and sleep better. win.
posted by theora55 at 10:14 AM on February 9 [1 favorite]
posted by theora55 at 10:14 AM on February 9 [1 favorite]
Beta blockers are often take by i.e. musicians for performance anxiety.
I have never taken them myself, but talking with quite a number of people people who have, they describe it more as moderating the adrenaline, anxiety, etc, rather than completely eliminating it. Basically it put them in that slot of having enough adrenaline to enhance the performance but not so much that you go into "freak out" mode.
Now, they were undoubtedly shooting for a dosage that would have that type of effect on them. I can't say how much tweaking it does or does not take to achieve that.
But I would say, there is some possibility you might actually perform better in an actual emergency situation, because you still have enough of the heightened affect to be helpful in focusing your attention but not so much that you freak out.
BTW by "freak out" I don't necessarily mean a complete meltdown. But under stress it can be hard to, for example, do things requiring fine motor skills like tie or untie a knot, unlock a door with a key, do simple math facts or calculations, remember key facts, or make clear-headed decisions. All those kinds of things in an emergency or stressful situation might be better with a beta blocker rather than worse.
posted by flug at 10:36 PM on February 9 [2 favorites]
I have never taken them myself, but talking with quite a number of people people who have, they describe it more as moderating the adrenaline, anxiety, etc, rather than completely eliminating it. Basically it put them in that slot of having enough adrenaline to enhance the performance but not so much that you go into "freak out" mode.
Now, they were undoubtedly shooting for a dosage that would have that type of effect on them. I can't say how much tweaking it does or does not take to achieve that.
But I would say, there is some possibility you might actually perform better in an actual emergency situation, because you still have enough of the heightened affect to be helpful in focusing your attention but not so much that you freak out.
BTW by "freak out" I don't necessarily mean a complete meltdown. But under stress it can be hard to, for example, do things requiring fine motor skills like tie or untie a knot, unlock a door with a key, do simple math facts or calculations, remember key facts, or make clear-headed decisions. All those kinds of things in an emergency or stressful situation might be better with a beta blocker rather than worse.
posted by flug at 10:36 PM on February 9 [2 favorites]
Response by poster: Just to say thanks everyone, I appreciate the anecdata as well as the expert medical explanation. I have postural tachycardia and it would be nice if my heart could Not Do That, but adrenaline is very helpful in sheep emergencies. Cardiologist appointment next month.
posted by Rhedyn at 4:10 AM on February 10 [3 favorites]
posted by Rhedyn at 4:10 AM on February 10 [3 favorites]
Well now I want to know about sheep emergencies. Guess I can use an Ask for it!
posted by sixswitch at 6:13 PM on February 10 [1 favorite]
posted by sixswitch at 6:13 PM on February 10 [1 favorite]
Response by poster: sixswitch, sheep emergencies are sometimes just sheep escaping containment, but more critically can be sheep getting hurt or sick, so I need to be able to catch them and transport them from wherever they are to a safe shed where I can tend to them. Worst case that's a 40+kg unwell and uncooperative animal on a steep slippery hillside in terrible weather, so a surge of enhanced physical and mental focus really helps!
posted by Rhedyn at 3:30 AM on February 11 [2 favorites]
posted by Rhedyn at 3:30 AM on February 11 [2 favorites]
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Beta blockers also don't block the effects of adrenaline uniformly - there are different types of beta receptors (beta 1, beta 2, etc) that are more or less present in different parts of the body (beta 1 mostly heart, beta 2 mostly lungs, etc), and different specific medications block different subtypes more or less.
posted by telegraph at 3:34 AM on February 9 [5 favorites]