Heart Rhythm Community
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612551 tn?1450025775

Metoprolol vs Atenolol for Heart Rate Control

I posted an update to my tread on "living with AFib", that touches on this subject.

I post here as I would like to draw specific attention to the difference I have learned mostly by the help of other patients who contribute to this Community and from web searches.  Strangely, in my mind, my Cardiologist never volunteered consideration of Atenolol even though I have complained to him for years (at least 10) that I suffer from dream problems, I call them trouble mares.  That is a subject for the "sleep disorders" Community to which I also contribute - so I'll I will not go into more detail here on that subject.

Following are my observations on day two of substituting Atenolol 25 mg twice a day for Metoprolol 25 mg twice a day.. both are regular, for Metoprolol it is called Tartrate, I think the Atenolol comes in only one normally longer lasting form.

Today in the early afternoon, following my third 25 mg dose of Atenolol at about 9 AM, I noticed some dizziness when I rose from a time sitting.  This is not unusual for me, but I checked my HR anyway (using my new Oximeter, subject of another post) and found even though I was then on my feet and had walked at least 10 feet my HR was in the mid 50s.  Prior to changing to Atenolol I rarely saw my resting HR below the low 70s.  I also note my resting HR yesterday and in the early hours of this morning were mostly 70s for resting, some 60s.  

I then went outside and did some physical work, spitting some Ash Hardwood for firewood.  Most of this splitting was done with a 4 ton electric splitter for which I had only to lift the rounds (upwards of 40 pounds I estimate) onto the splitter and then pull them splits apart and throw on a stack.  This went on for perhaps 40 minutes with me having to revert to an 8 pound maul (sledge hammer) and Wedge to split some rounds that stopped the light duty electric splitter.  I estimate I made no more than 30 swings with the heavy maul. This fairly strenuous exercise did make me a bit breathless and I found my HR only in the upper 90s.  Before Atenolol I recall a similar workout would have put my HR over 130, or near my maximum allowed rate.

Research on the web says that Atenolol is much longer lasting than Metoprolol and suggests that Metoprolol Tartrate has to be taken twice a day... Atenolol only once !  Strangle, again, my Cardiologist who issued a prescription for Atenolol upon my request to be allowed to try it is for 25 mg twice a day.

Given my unusual low HR I conclude that taking the Atenolol twice a day would be more comparable to taking the Metoprolol (same 25 mg) Slow Release twice a day - thus being equivalent to an increase in BB level, thus the lower HR.

I plan to skip my bedtime does, treating my morning Atenolol as a long lasting once a day. This will also cut my intake of BB from 50 mg a day to 25 mg.  I will keep a close watch on my HR and be sensitive to any unusual heart symptoms, the current unusual low HR going back to upper 60s or lower 70s at rest being considered normal, not unusual.   I look to with some hope that the reduced dose coupled with the lower brain side-effect of Atenolol will reduce the problem dreaming.  I fully expect to wake up in the early AM hours and will check my HR then, I keep my Oximeter (with HR meter) on my nightstand.
44 Responses
Avatar universal
Atenolol works great for me. One cardiologist insisted I switch to bisporolol. I did, and it was terrible. Had to go to the hospital because my heart rate wouldn't come down. Switched back to atenolol and haven't had any problems since.
612551 tn?1450025775
Thanks, do you take Atenolol only once per 24 hours?  As read about it on the Web I understood Atenolol to be more equivalent to Metoprolol SR in terms of life, Atenolol is not metabolized by the liver as Metoprolol is.

Can you share what does you take?  
1569985 tn?1328251082
Jerry -- My Rx for Atenolol is 2 25 mg. tablets per day.  I have gone from 1 to 1-1/2 per day to 2 tablets per day after my recent cardioversions.  I am weaning off of it now and am back to about one tablet a day.  I break the tablet in "large 1/4's" or just a bit less than half for each dose, every 8 hours.  My EP said I could do it however it wanted.  If I took an entire pill, my bp would plummet like a stone.  I keep a check on my hr and bp and if they are down too low, I delay my next dose.  My heart rates stays in the 50's.  If it drops to 55 or so, I delay the dose.  A 60 hr feels fast to me now.  I am having some fatigue since my Norpace was increased after my last afib episode.  My thyroid is low, so that may factor into the tiredness too.  You might want to try 1/2 tablet every 12 hours, rather than one tablet every 24.  For me, my bp and heart rate would be up if I didn't spread it out over the course of the day.  Keep us posted on how you do.  I hope it works out better for you.  Sounds like it is keeping your hr lower with less meds.
Avatar universal
I only take 25mg once a day. If I were to take another dose at night it would lower my pulse too much, and I've also read that taking it at night can cause insomnia as well. I find on 25mg my heart rate sits around 60--75 for most of the day which is perfect for me since my heart rate is affected by my IST during the day time, and usually comes back down to a normal rate on its own at night time.
1423357 tn?1511089042
Hi Jerry.  As a retired "double E", I imagine you already realize this but it bears mentioning:  You must consider that the effect seen for  a given weight of Metoprolol Tartrate cannot be compared to the same weight of Atenolol.  In other words, I don't think you can freely exchange drugs and use the same weight.

So if you were formerly on 25mg of Metoprolol 2X/day (which I know from experience is a fairly low dose), 25mg of Atenolol 2X/day may be huge in comparison.  I had been on Metoprolol dosages as high as 200mg/day (not fun), and my cardiologist said he has prescribed dosages as high as 400mg./day.

By the way, you can compare similar weights of Metoprolol Tartrate and the time release version called Metoprolol Succicate if you consider the longer half life of the latter version.
1423357 tn?1511089042
One other thing.... I originally got on Metoprolol Succinate not for my SVT or to control blood pressure, but to use the side effect of slowing the heart rate.  I had complained about awakening in the middle of the night with an elevated sinus pulse.  Unfortunately, my physician never took into consideration that my elevated heart rate could have been caused by something.  It turned out that I had very severe obstructive sleep apnea which was diagnosed several years later by a new physician.  I continue to take it today at 75mg/day for bp and arrhythmia control, along with heart attack survivability.  At 62, that unpleasant thought must be taken into consideration.
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